Dissertations / Theses on the topic 'Marine ecosystem management – Scotland'

Coastlines are particularly susceptible to the necessary trade-offs which occur between different ecosystem services. Should the areas be managed for biodiversity or for people? Where sandy beaches are found there is usually a management decision to be made between managing for recreation or for biodiversity. Many popular tourist beaches (particularly those with a Beach Award) are often groomed with mechanical equipment to remove any stranded seaweed and associated litter which can get entangled in the wrack. This is likely to be having a negative impact on coastal biodiversity, with wide ranging implications for the entire habitat, including the intertidal zone, sand dunes and shorebirds. Beached wrack should be allowed to naturally decompose providing a habitat for numerous species of macro-invertebrates. These macro-invertebrate communities not only include many endemic species found exclusively along the strandline but they also provide a very rich source of food for shorebirds. The re-mineralised nutrients resulting from the decomposed macrophytes should then become available to provide a rich source of nutrients to dune, strandline and marine ecosystems populations of the strandline. In previous studies grooming has been shown to have a negative impact on the invertebrates of the strandline and this study reveals that tidal range has an effect on the impacts of grooming with a higher tidal range having a more negative impact on the invertebrates. A study to observe the impacts of grooming on both adult plant and seed bank communities of the sand dunes found that grooming is having a negative impact on these populations. Grooming is predominantly driven by beach managers who aspire to gain Beach Awards in order to attract tourists to their beaches. Using non-market valuation in the form of a stated preference choice experiment and a travel cost model, it was observed that Beach Awards are not valued by beach goers but are instead influenced to visit a particular beach by good bathing water quality, high levels of biodiversity and low levels of litter. It was also shown that stranded seaweed on the beach does not deter visitors. Future management suggestions include attempting to reduce the confusion arising from the presence of multiple beach awards by either removing them altogether or by making their criteria more clear and direct with consistency in their design and designation. Bathing water quality should be completely removed from the Beach Award system and real-time information in the form of electronic signage and a publicly available App should replace it.

This thesis assessed the current prospect for implementing an ecosystem-based management for fisheries (EBFM) in the Bay of Bengal Large Marine Ecosystem from national and regional level perspectives. A central result of the study is that the governance concept had been defined and used imprecisely in the literature. The way the different elements constitute EBFM revealed that both Bay of Bengal LME countries and existing regional fisheries organisations are unlikely to satisfy all the elements on the EBM checklist. The study also observes that the Bay of Bengal countries do not share a common understanding of EBFM.

The objective of this thesis is to update the Mori-Butterworth (2006) model of the krill-predator dynamics of the Antarctic ecosystem. Their analysis aimed to determine whether predator-prey interactions alone could broadly explain the observed population trends of the species considered in their model. In this thesis, the Antarctic ecosystem is outlined brie y and details are given of the main krill-eating predators including whales, seals, fish and penguins, together with an historical record of the human harvesting in the region. The abundances and per capita krill consumption of the krill-predators are calculated and used to determine the main krill-predators to be used in the updated model developed. These predators are found to be the blue, fin, humpback and minke whales and crabeater and Antarctic fur seals. The three main ship surveys (IDCR/SOWER, JARPA and JSV) used to estimate whale abundance, and the abundance estimation method itself (called distance sampling), are summarised. Updated estimates of abundance and trends are listed for the main krill-predators. Updated estimates for the biological parameters needed for the ecosystem model are also reported, and include some differences in approaches to those adopted for the Mori-Butterworth model. The background to the hypothesis of a krill-surplus during the mid-20th century is discussed as well as the effects of environmental change in the context of possible causes of the population changes of the main krill-feeding predators over the last century. Key features of the results of the updated model are the inclusion of a depensatory effect for Antarctic fur seals in the krill and predator dynamics, and the imposition of bounds on Ka (the carrying capacity of krill in Region a, in the absence of its predators); these lead to a better fit overall. A particular difference in results compared to those from the Mori-Butterworth model is more oscillatory behaviour in the trajectories for krill and some of its main predators. This likely results from the different approach to modelling natural mortality for krill and warrants further investigation. That may in turn resolve a key mismatch in the model which predicts minke oscillations in the Indo-Pacific region to be out of phase with results from a SCAA assessment of these whales. A number of other areas for suggested future research are listed. The updated model presented in this thesis requires further development before it might be considered sufficiently reliable for providing advice for the regulation and implementation of suitable conservation and harvesting strategies in the Antarctic.

Even as global fisheries are in decline, participation in ecosystem-based marine recreational activities (MRAs), defined here as recreational fishing, whale watching and diving, has increased around the world, adding a new dimension to human use of the marine ecosystem and another good reason to strengthen marine ecosystem management measures worldwide. After compiling available data for maritime countries, a meta-analysis was used to estimate the yearly global benefits of the largest MRAs. Results suggest that 121 million people a year participate in MRAs, generating 47 billion USD in expenditures and supporting one million jobs. Aside from offering the first global estimation of socioeconomic benefits from MRAs, this work provides insights on their drivers of participation and possible ecological impacts. In the case of whale watching, potential benefits are estimated for maritime countries that do not currently engage in this industry based on ecological and socio-economic criteria. Results suggest that whale watching could generate an additional 413 million USD in yearly revenue, supporting 5,700 additional jobs; this would bring the total potential benefits from the global whale watching industry to over 2.5 billion USD in yearly revenue, supporting 19,000 jobs. Recreational fishing is the largest MRA in the world, and can be a vital component of regional economies. Using available fisheries and ecosystem data, an Ecopath model was used to explore the ecological and economic effects of specific fisheries management measures in Baja California Sur, Mexico, particularly regarding longlining effort reductions and billfish bycatch. Results suggest that currently mandated policies will have little effect on marlin abundance in the area. The effects of ecosystem dynamics in an already overfished system must not be overlooked, as they can negate or even reverse desired outcomes from management. All results are discussed from an economic and conservation policy perspective, with emphasis on potential benefits and limitations.

This study reviews a training programme on Marine Protected Area (MPA) management. It notes that although MPAs are well promulgated under legislation, reports have found that there are still key challenges facing the management of these areas. The research examines how the course was developed following the Lemm and Attwood (2003) report and designed to develop competences for effective MPA management. The aim is to identify how a MPA management training course produced competences apposite to the workplace settings of the participants. An interpretive case study method was used, in two phases. The first phase explored salient issues in MPA management in South Africa through analysis of the two key ‘state of MPA management’ reports and interviews with MPA professionals. The second was an analysis of the South African Marine Protected Area Management Training Course. This involved interviews with course designers, a review of the course materials, interviews with past course participants, and an analysis of course evaluations. Evidence emerged that supported the following findings: Challenges and problems facing MPA management still exist. Competence in key areas of MPA management was addressed in an effective work-integrated approach. Social learning was a key process in the development of these competences. The competences articulate well with the workplace of participants. Gaps exist between some of the management issues and the competences developed by the course, and some aspects of the course design are ineffective. From these findings it is concluded that: The course took up the majority of issues in MPA management through the development of key competences. The course design facilitated the development of these competences. The competences developed through the course are relevant to the workplace of MPA professionals. The research found that the course adequately addresses issues in MPA management through the development of competences. Some recommendations for improvements are made.

Ecosystem restoration and management seek to repair, improve, or maintain a suite of desired environmental conditions for a specific ecosystem. However, when working on complex ecosystems, where do you start and how can you tell when you are successful? Forecasting ecological effects of restoration scenarios provides a basis for project evaluation and selection of restoration alternatives. Ecological monitoring is essential for assessing ecosystem condition over time. In an integrated approach to adaptive management a forecasting model simulates system response and is validated by monitoring programs to measure actual system response. Monitoring can then feed back as a passive adaptive management tool to modify restoration or management plans. Directed research driven by uncertainties in models and ecosystem response is an active adaptive management strategy for learning and provides a basis to calibrate models. Since all components of an ecosystem cannot be modeled or monitored effectively, scientists and managers rely heavily on ecological indicators to reveal information about ecosystem status and trends. As a result, modeling and monitoring programs focus on indicators that maximize information on ecosystem patterns and processes while minimizing cost and effort. InSouthwest Florida, conceptual ecological models were constructed to support the framework of an applied science strategy by identifying indicators for estuarine ecosystem assessment and evaluation. Forecasting models were created as a set of stressor response (habitat suitability) models for individual species and incorporated into a spatially explicit decision support system to guide selection of the most beneficial restoration alternative.

Includes bibliographical references (p. 77-84).
The World Summit on Sustainable Development (WSSD) Plan of Implementation encourages the implementation of an Ecosystem Approach to Fisheries (EAF) management by 2010. Signatory countries, which include Namibia, have adopted this as being necessary for the sustainable use of their marine resources. However, there has been little progress made towards developing simple structured guidelines for implementing an EAF within fisheries management organisations. As part of an EAF project implemented by the BCLME (Benguela Current Large Marine Ecosystem) programme, a series of Ecological Risk Assessments (ERA) were conducted for selected fisheries, which focussed on identifying all major issues related to EAF that are not adequately addressed by present management strategies. This methodology was repeated for the Namibian Rock Lobster fishery. Highly prioritised issues from the workshop were used to construct causal maps and value trees, for which indicators were suggested in consultation with stakeholders. The results of the ERA confirmed that there is a severe lack of transparency and shared understanding among stakeholders in the Namibian Rock Lobster Fishery, which is causing high tension and user conflict within the fishery. However, the importance and strength of the ERA process was found to lie in the discussion that it facilitates amongst stakeholders. Causal maps proved very useful in placing perspective on the perceived problems associated with the current management of the Rock Lobster fishery and the hierarchical structuring of value trees proved extremely useful in facilitating the transparency of the process. A list of specific objectives and suggested indicators is presented here, but there remains paucity in the data that are needed to inform some of these suggested indicators. Thresholds for these suggested indicators are defined here and are needed for evaluating the indicators for combination into an overall evaluation of the implementation of an EAF in this fishery. Expert systems are suggested here as a good tool to do so through synthesizing information from a large number of indicators for the decision-making process and to readily incorporate updated information. The tentative set of indicators presented here needs further work. However, the results of the present thesis can be used in designing such a system, to the benefit of the Namibian Rock Lobster fishery and the ecosystem this fishery depends on.

This thesis aims to analyse the law-making of EBFM (ecosystem-based fisheries management) as a post-development of the United Nations Convention on the Law of the Sea (UNCLOS), and as one of the instruments to avoid stocks collapse, destruction of critical habitats, ensuring a healthy marine environment. This analysis focuses on UNCLOS as the main legal instrument governing the use of the ocean and its living resources in the light of recent developments of international law in accordance with the Vienna Convention on the Law of the Treaties. Therefore, the research concludes that a systemic interpretation of UNCLOS in the light of recent conventions and other legal instruments among their parties provides a legal basis for the implementation of EBFM in marine areas beyond national jurisdiction. The research also discusses the role of regional fisheries management organisations as a key element for the implementation of EBFM. The thesis then looks beyond the issue of interpretation and proposes actual means for the implementation of EBFM in accordance with international law. It suggests that an implementing agreement to UNCLOS should be adopted in order to regulate the establishment of marine protected areas as a tool to EBFM in marine areas beyond national jurisdiction.

Presence of coastal aquaculture activities in marine landscapes is growing. However, there is insufficient knowledge on the subsequent ecological interactions between these activities and marine fish communities. The overall aim of this thesis was to evaluate the direct and indirect ecological effects of aquaculture activities on marine fish communities in Scotland. A combination of empirical and modelling approaches was employed to collect evidence of how aquaculture activities affect marine fish communities at the individual, population and ecosystem levels around coastal sea cages. The two fish farms evaluated in this research provided the wild fish sampled near the sea cages with a habitat rich in food resources which is reflected in an overall better biological condition. Results of the stomach content analysis indicated that mackerel (Scomber scombrus), whiting (Merlangius merlangus) and saithe (Pollachius virens) sampled near sea cages consumed wasted feed which was also reflected in their modified FA profiles. The overall effects of the two fish farms were more pronounced in young whiting and saithe than in mixed aged mackerel sampled near the sea cages. The phase space modelling approach indicated that the overall potential for fish farms to act at the extremes as either population sources (a habitat that is rich in resources and leads to an overall improved fitness) or ecological traps (a habitat that appears to be rich in resources but is not and leads to an overall poor fitness) are higher for juvenile whiting than for mackerel. Based on the empirical evidence and literature the two fish farms are more likely to be a population source for wild fishes. Using an ecosystem modelling approach indicated that fish farming impacts the food web in a sea loch via nutrient loading. Mussel farming relies on the natural food resources and has the potential to affect the food web in a sea loch via competing with zooplankton for resources which can affect higher trophic levels. The presence of both activities can balance the overall impact in a sea loch as compared to the impact induced if each of these activities were present on their own. Both activities have the potential do induce direct and indirect effects on the wild fish and the entire sea loch system. The results of this PhD identified several gaps in data and thus could be used to improve future sampling designs. It is important to evaluate the cumulative effect of the presence of aquaculture activities in terms of nutrient loading and physical structure in the environment. Using a combination of empirical and modelling approaches is recommended to gain further insight into the ecological impacts of aquaculture activities on wild fish communities. Results of this PhD study could lead to more informed decisions in managing the coastal aquaculture activities. Establishing coastal fish farms as aquatic sanctuaries can be of an advantage to increase fish production and conserve species that are endangered provided that no commercial and recreational fishing is allowed nearby. It would be useful to have long term monitoring of the fish stocks around the cages and if there is any production at the regional level. Additionally, information on behaviour, migration patterns should be collected to understand the impacts of aquaculture activities on fish stocks. From an aquaculture perspective, ecologically engineered fish farms in addition to careful site selection in new aquaculture developments may improve nutrient loading into the ecosystem.

Externalities caused by human transformations in ecosystems structure and functioning has been threatening environmental quality and social welfare in all socioecological systems, including coastal zones. Environmental Impact Assessment (EIA) is an instrument widely used to evaluate the feasibility of developments and projects that can potentially provoke changes in biophysical-human environment. However, EIA generic and fragmented approach has not properly been considering people and environmental particularities, such processes and benefits to society, in decision making. Ecosystem-Based Management recently emerged as a strategy that can qualify EIA, by embracing ecosystem processes and services (ES), human dimensions, social engagement and Local, Traditional and Scientific Ecological Knowledge. Using a case study of a contested Port expansion in São Sebastião, São Paulo, Brazil, that endangered the sustainability of an adjacent bay (Araçá Bay), we selected analytical categories comprising different stakeholders, ecosystem services and disturbances scenarios to understand the role of EBM in coastal EIA. We presumed that stakeholders with deeper relationships with the place could provide more comprehensive assessments about changes in the availability of main local ES, as a result of greater sense of place, access to different sources of knowledge and opportunities to social participation. Also, an EBM approach would provide a more robust, i.e., a wider and more integrated assessment of impacts in the provision of the ES than the Environmental Impact Study (EIS) of the port expansion. We performed in-depth interviews with four different groups of stakeholders and analyzed their speeches with discourse analysis and statistical inquiries to assess ES scores of occurrences in current (Two-way ANOVA) and disturbances scenarios (Repeated measures ANOVA and PERMANOVA), besides their main argumentation patterns. We compared these results with the port expansion EIS to assert to robustness of the method. The groups had different perceptions from each other, which depended on the scenario and ES evaluated. We corroborated the hypotheses: groups\' closer, deeper and more engaged relationships with the place had more comprehensive assessments of changes in the ES; and stakeholders perceptions reflected trade-offs of the local urban conflicts, providing a higher variety and more integrated assessments of impacts than the Environmental Impact Study of the Port expansion. The diversity of forms of knowledge, behaviors and functions, in temporal and spatial scales, proved to be valuable for the groups\' assessments of resource and the territory, and the choice of the analytical categories was fundamental to consolidate the understanding of local socioecological processes. We concluded that the method tested was efficient and respected the intrinsic variability of coastal zones and its function as a socioecological system to assert that EBM has a great potential to improve the effectiveness of EIA.
As externalidades causadas por transformações humanas na estrutura e funcionamento dos ecossistemas têm ameaçado a qualidade ambiental e o bem-estar social em todos os sistemas socioecológicos, incluindo as zonas costeiras. A Avaliação de Impacto Ambiental (AIA) é um instrumento amplamente utilizado para avaliar a viabilidade de empreendimentos e projetos que podem provocar potenciais mudanças no ambiente biofísico-humano. No entanto, a abordagem genérica e fragmentada da AIA não tem devidamente considerado as pessoas e as particularidades ambientais, como os processos e valores sociais, na tomada de decisões. A Abordagem Baseada em Ecossistemas (ABE) surgiu recentemente como uma estratégia que pode qualificar a AIA, abrangendo processos e serviços ecossistêmicos (SE), dimensões humanas, engajamento social e Conhecimento Ecológico Local, Tradicional e Científico. Utilizando um estudo de caso de uma contestada ampliação portuária em São Sebastião, São Paulo, que ameaçou a sustentabilidade de uma baía adjacente (a Baía de Araçá), selecionamos categorias analíticas que compreendem diferentes stakeholders (ou principais atores), serviços ecossistêmicos e cenários de perturbações para entender o papel da ABE na AIA costeira. Presumimos que os stakeholders com relações mais profundas com o local poderiam fornecer avaliações mais abrangentes sobre mudanças na disponibilidade dos principais SE locais, como resultado de maior senso de pertencimento, acesso a diferentes fontes de conhecimento e oportunidades para participar socialmente. Além disso, assumimos que a ABE proporcionaria uma AIA mais robusta, ou seja, com uma perspectiva mais ampla e mais integrada dos impactos na provisão dos SE do que Estudo de Impacto Ambiental da expansão portuária. Realizamos entrevistas em profundidade com quatro grupos diferentes de stakeholders e analisamos o conteúdo por meio de análise de discurso e testes estatísticos para avaliar as ocorrências dos SE no cenário atual (ANOVA de duas vias) e nos cenários de perturbações (ANOVA de medidas repetidas e PERMANOVA), além dos principais padrões de argumentação dos stakeholders. Comparamos esses resultados com o Estudo de Impacto Ambiental da ampliação do Porto para afirmar a robustez do método. Os grupos apresentaram diferentes percepções uns dos outros, o que dependeu do cenário e do SE avaliado. Nós corroboramos as hipóteses: grupos com relações mais próximas, mais profundas e mais comprometidas com o local tiveram avaliações mais abrangentes das mudanças dos SE; e as percepções dos stakeholders refletiram os trade-offs (ou qualidade, aspecto) dos conflitos urbanos locais, proporcionando avaliações mais variadas e integradas de impactos do que o Estudo de Impacto Ambiental da expansão portuária. A diversidade de formas de conhecimento, comportamentos e funções, em escalas temporais e espaciais, se provaram valiosas para avaliações dos grupos sobre os recursos e o território, e a escolha das categorias analíticas foi fundamental para consolidar a compreensão dos processos socioecológicos locais. Concluímos que o método testado foi eficiente e respeitou a variabilidade intrínseca das zonas costeiras e sua função como um sistema socioecológico, o que afirmou que a ABE tem um grande potencial para melhorar a eficácia da AIA.

Includes bibliographical references
An Ecosystem Approach to Fisheries management (EAF) offers a holistic approach for sustainable fisheries management by extending the traditional target resources-orientated management (TROM) to include wider social-ecological dimensions of fisheries. An EAF requires balancing of multiple, often conflicting objectives, effectively dealing with complexity and uncertainty, and engaging with diverse groups of stakeholders. Various tools within the field of Multi-criteria Decision Analysis provide a formal approach which takes explicit account of multiple criteria, while effectively dealing with risk and uncertainty. A knowledge-based tool was developed in this thesis to assess the efficacy of EAF implementation for the ecological well-being dimension in the South Africa sardine fishery. An iterative, participatory approach was adopted for its implementation. The modelling philosophy applied a rapid prototyping approach, and an applied research perspective was employed to direct the research. A broad group of stakeholders participated in indicator selection, tool design, and interpretation. The knowledge-based tool provided a hierarchical framework for seven specific management objectives to which eleven ecological indicators were linked. Time series (1987-2009) were collated for each indicator, and a utility approach was used to transform indicators to a common scale. Weights for indicators and objectives were agreed to by stakeholders and combined through the objectives' hierarchy using weighted means. The resulting outputs were discussed in detail during focus group meetings to ensure that the tool was clearly presented and as intended helped improve the stakeholder's understanding of the process. It was confirmed that the 20 knowledge-based tool presents a transparent, repeatable and scientifically defensible approach, suitable to meet management requirements. The tool development process was useful in bringing diverse stakeholder groups together, and through applying the tool as a boundary object, has helped to bridge the boundary between the TROM and EAF research communities. Encouraging stakeholder interaction offers opportunities for social learning, which if carefully facilitated through the tool development process is likely to enhance the outcomes of this process and support more generally in bridging boundaries to EAF implementation. The combined focus on tool development and social processes supports effective implementation of an EAF in the South African small pelagic fishery and provide a model for other fisheries.

Ecosystem-based management (EBM) offers a holistic evaluation of tradeoffs between human activities, but this offer rests upon a foundation of science. In this thesis, I assessed and advanced the knowledge-base for EBM in five ways, focusing on nonnative species in estuarine ecosystems. In Chapter 2, I tested for the comprehensiveness of research that connects the impacts of anthropogenic activities to changes in ecosystem service production, employing a literature review of estuarine ecosystems. Research on these connections virtually never included the relationship of activities to ecosystem services production, presenting an impressive gap in research for evaluating tradeoffs using EBM. I addressed the sufficiency of existing information regarding nonnative species in eelgrass beds in Chapter 3. I tested the relationship of nonnative species in British Columbia’s (BC) eelgrass beds with arrival pathways and environmental selection factors. There were few (12) nonnatives in BC’s eelgrass; all associated most commonly with aquaculture facilities and warm temperatures. Existing reports included the majority of nonnatives: only one species, the bamboo worm Clymenella torquata, represented a new record, as I described in Chapter 4. Impacts of nonnatives are difficult to limit after invasion. In Chapter 5, I developed an approach for characterizing the potential economic impacts of nonnatives. I focused on European green crab, a nonnative species that has not yet arrived in Puget Sound, Washington. At a range of invasion densities and increasing calorie diets, I calculated a value-at-risk to shellfish harvest ranging from $1.6 - $41 million USD. Such calculations can aid in preparation for impending invasion by motivating prevention and mitigation efforts. Nonnative management is often based on the available understanding of the impacts on native species. In Chapter 6, I assessed available research on the impact of nonnative seagrass, Zostera japonica, in northeast Pacific estuaries. My results suggested existing studies that quantitatively test Z. japonica impacts are insufficient to comprehensively assess the effects of this invasion. My dissertation research highlights the need for research to determine the ecosystem role of nonnatives in their invaded range through analysis of quantitative studies across broad scales.

Human activity can affect the soil in ways which are traceable long after the land has been given over to other uses, and past land management practices can be reconstructed by investigation of these relict characteristics. In some regions the addition of fertilising materials to the arable soils has created artificially deepened anthropogenic topsoils which can be over 1m thick. Such relict soils are found all over the world, and are widespread in north-western Europe. This work focuses on the anthropogenic soils in the Northern Isles, which were formed from the Neolithic period up until the 20th century. Three multi-period sites were investigated using thin section micromorphology, organic/inorganic phosphate analysis, soil magnetism, particle size distribution, loss on ignition and soil pH. Current views of anthropogenic soil formation, based on pedological investigation and historical documentary sources, are that they are formed as a result of the addition of domestic animal manures and turf used as animal bedding to arable areas. This project sets out to test the hypothesis that in fact anthropogenic soils are the result of a wide range of formation processes which took place over extended periods of time. The hypothesis has been tested by analysing soils and associated middens of different dates, which have been sealed and protected by blown sand deposits. The results have shown that in the Neolithic period arable soils were created by cultivating the settlement's midden heaps as well as by adding midden material to the surrounding soils. In the Bronze Age human manure, ash and domestic waste were spread onto the fields around the settlements to create arable topsoils up to 35cm thick. In the Iron Age arable agriculture was intensified by selective use of organic manures on one of the sites investigated, but organic waste material was not used as efficiently as it was in later periods, and on both sites it was allowed to accumulate within the settlements. In the Norse period, when the intensive system used in historical times appears to have originated, organic waste may have been used more efficiently. These changes appear to reflect a greater organisation of land resources and manuring strategies and increased demand for arable production over time.

The overexploitation of marine living resources challenges the scientific community for developing new analytical approaches providing effective tools for marine management, ensuring long-term conservation of the harvested and threatened species. Currently, the scientific efforts are mainly focused on the development of techniques and concepts to improve the assessment and management of these populations from a holistic point of view within the framework of the Ecosystem Based Management (EBM). While the principles and objectives of EBM have been accepted by the scientific community and those responsible for the management of the fisheries and conservation, there is not a consensus about how it should be implemented. One of the decisive reasons hindering its implementation is the complexity related to the modeling of complex socio-ecological systems, which covers from environmentally driven effects to social aspects in the management. Focusing on key processes of ecosystems such as the relationships between species ecological processes and essential habitats offers a path to advance towards the implementation of EBM without having to reach the development of excessively complex end-to-end models of an ecosystem. The research developed along this PhD has two main objectives. 1) the application of new concepts and techniques to improve the characterization of essential habitats of two top predator species, the dusky grouper (Epinephelus marginatus, Lowe 1834) and the Atlantic bluefin tuna (Thunnus thynnus, Linnaeus 1758). 2) To propose new methodologies based on habitat information to improve current assessment and management approaches of those species. Conservation of dusky grouper and Atlantic bluefin tuna exploited populations is tackled today from different technical approaches due to differences in their ecological characteristics. Dusky grouper is a highly resident species that inhabits rocky bottoms in coastal Mediterranean ecosystems, where conservation of exploited populations through the establishment of marine protected areas has provided positive results. Atlantic bluefin tuna is a highly migratory pelagic species with a wide geographical distribution along the Atlantic waters, and performs long migrations during spring to reach the spawning areas, among of which the Balearic Sea is one of the main ones. Management of Atlantic Bluefin tuna is approached mainly by technical measures such as minimum weight regulation and limitations in the total allowable catches, established as a function of the status of the adult stock populations calculated from virtual population analysis. In recent years the application of traditional landscape ecology techniques to characterize habitat in the coastal environment has promoted the beginning of the seascape ecology discipline. These techniques have been applied here to improve the definition of dusky grouper essential habitats and to identify changes in habitat use along ontogenetic development. The definition of dusky grouper habitats at different developmental stages provided insights about the species ecology and provided criteria for designing more efficient Marine Protected Areas (MPAs). Findings from the study of dusky grouper essential habitat and the improvement on habitat definition by using seascape metrics provide the basis for developing new methods for MPA design within the framework of Rapid Assessment Programs. Therefore, in this PhD a method is proposed for rapid multidisciplinary environmental assessment of coastal areas for the design and management of MPAs. This method provide tools for the selection, design and management of coastal MPAs when time, budget or potential human pressures, either alone or in combination, create an urgent need for prioritization. The conceptual scheme applied to link littoral species with essential habitats and the transference to management has been adapted to the pelagic environment. Transferring ideas and techniques of seascape ecology to the pelagic realm was not straightforward. New pelagic seascape metrics have been proposed and tested to study the Atlantic Bluefin tuna spawning habitats around the Balearic Sea, advancing in the knowledge of species ecology. The developed pelagic seascape metrics have been applied to the development of a spawning habitat forecasting model to assist managers. This methodology is entirely based on oceanographic data obtained from operational data sources. Finally, monitoring and modeling Atlantic bluefin tuna pelagic essential habitats at larval stages allowed developing new larval indices, providing information on Atlantic bluefin tuna adult eastern stock population.
L’estat actual dels recursos vius i dels ecosistemes marins suposa un desafiament constant per a la comunitat científica, que obliga a un progrés continu que asseguri, a llarg termini, la seva explotació sostenible i la seva conservació. Avui en dia els esforços en la investigació se centren, en gran mesura, en el desenvolupament de tècniques i conceptes per millorar l’avaluació i la gestió d’aquestes poblacions des d’un punt de vista holístic en el marc de la gestió basada en l’ecosistema (EBM per les seves sigles en anglès). Mentre que els principis i objectius de l’EBM han estat acceptats per la comunitat científica i pels responsables de la gestió de la pesca i de la conservació, no existeix un consens sobre com s’ha d’aplicar. Un dels motius determinants que obstaculitzen la seva implantació és la complexitat associada a la modelització de sistemes socio-ecològics complexos, que abasta des dels efectes ambientals fins a aspectes socials en la gestió dels recursos. La identificació de processos clau en un ecosistema, com puguin ser les relacions entre l’ecologia de determinades espècies amb els seus hàbitats essencials, ofereix una possibilitat per avançar cap a l’aplicació de la EBM sense haver d’assolir el desenvolupament de models super-complexos que abordin tots els processos que ocorren en un ecosistema. Els diferents estudis desenvolupats al llarg d’aquesta tesi doctoral tenen dos objectius principals. En primer terme s’ aborda l’aplicació de noves tècniques i conceptes per tal de millorar la caracterització dels hàbitats essencials de dues espècies marines localitzades en els estatges superiors de la cadena tròfica, com són l’anfós (Epinephelus marginatus, Lowe 1834) i la tonyina vermella (Thunnus thynnus, Linnaeus 1758). En segon terme, el desenvolupament de metodologies basades en la informació obtinguda sobre els seus hàbitats essencials, la qual cosa permetrà millorar l’avaluació i gestió de les poblacions d’aquestes espècies. Avui dia, la conservació de les poblacions explotades de l’anfós i la tonyina vermella s’aborden des d’enfocaments ben diferenciats, sobre la base de les seves característiques ecològiques. L’anfós és una espècie altament resident que habita fons rocosos dels ecosistemes costaners de l’oceà Atlàntic, l’oceà Índic i el mar Mediterrani. La conservació de les seves poblacions explotades es basa principalment en l’establiment d’àrees marines protegides. Per la seva banda, la tonyina vermella és una espècie pelàgica amb una àmplia distribució geogràfica al llarg de l’Atlàntic, que realitza llargues migracions durant la primavera per arribar a les àrees de reproducció, entre les quals s’hi troba el Mar Balear. La gestió d’aquesta espècie es basa, principalment, en l’establiment de quotes de pesca a partir de l’avaluació de l’estat de les poblacions mitjançant l’aplicació de models monoespecífics. En els darrers anys l’aplicació de tècniques procedents de l’ecologia del paisatge terrestre (landscape ecology) en estudis d’ecologia del medi costaner ha donat lloc a l’inici de la “ecologia del paisatge marí” (seascape ecology). En els estudis desenvolupats en el marc d’aquest doctorat s’han aplicat aquestes tècniques per millorar la definició dels hàbitats essencials de l’anfós i per identificar canvis en l’ús de l’hàbitat al llarg del seu desenvolupament ontogènic. La millora en la identificació dels hàbitats essencials de l’anfós a diferents etapes del seu desenvolupament ha proporcionat informació rellevant sobre la seva ecologia i criteris per al disseny d’àrees marines protegides més eficients quant a la conservació d’aquesta espècie. Els resultats obtinguts durant l’estudi dels hàbitats essencials de l’anfós i la millora en la caracterització de l’estructura dels hàbitats a través de l’aplicació de mesures de paisatge submarí han proporcionat la base per al desenvolupament d’una metodologia de disseny d’àrees marines protegides en el marc dels programes d’avaluació ràpida (RAPs per les seves sigles en anglès). En aquesta tesi doctoral es proposa un mètode per a l’avaluació ràpida d’àrees costaneres des d’un enfocament multidisciplinari. Aquest mètode proporciona eines per a la selecció, disseny i gestió d’àrees marines protegides costaneres quan el factor temps, el pressupost o l’acció humana, ja sigui individualment o combinats, crea una necessitat urgent de priorització. L’esquema conceptual aplicat en l’anàlisi de les relacions entre l’ecologia de l’anfós i els seus hàbitats essencials i la transferència d’aquesta informació a la millora en l’avaluació i gestió de l’espècie s’ha adaptat a l’ambient pelàgic. La transferència d’idees i tècniques de l’ecologia del paisatge marí a l’ambient pelàgic ha suposat un repte al llarg d’aquest doctorat. S’han proposat noves mètriques de paisatge marí pelàgic, que s’han aplicat en l’estudi dels hàbitats de reproducció de la tonyina vermella en el Mar Balear, la qual cosa ha permès avançar en el coneixement de l’ecologia d’aquesta espècie i d’altres de túnids. Aquests avanços han permès el desenvolupament d’un model de predicció de la localització de les zones de reproducció de la tonyina a les Balears, basats completament en l’aplicació de dades procedents de l’oceanografia operacional (teledetecció i models hidrodinàmics). Finalment, la monitorització dels estadis larvaris de la tonyina vermella i l’anàlisi dels seus hàbitats essencials han permès desenvolupar índexs d’abundància larvària, i demostrar que la informació sobre l’hàbitat millora significativament l’avaluació d’aquest índexs. Aquests índexs larvaris estàn permetent analitzar l’evolució de la fracció adulta de la població oriental de tonyina vermella de l’Atlàntic, que es reprodueix al Mediterrani.
El estado actual de los recursos vivos y de los ecosistemas marinos supone un desafío constante para la comunidad científica, obligando a un progreso continuo que asegure, a largo plazo, su explotación sostenible y su conservación. Hoy en día los esfuerzos en la investigación se centran, en gran medida, en el desarrollo de técnicas y conceptos para mejorar la evaluación y gestión de estas poblaciones desde un punto de vista holístico en el marco de la gestión basada en el ecosistema (EBM por sus siglas en inglés). Mientras que los principios y objetivos de la EBM han sido aceptados por la comunidad científica y los responsables de la gestión de la pesca y la conservación, no existe un consenso sobre cómo debe aplicarse. Una de las razones determinantes que obstaculizan su implementación es la complejidad asociada a la modelización de sistemas socio-ecológicos complejos, que abarca desde los efectos ambientales hasta aspectos sociales en la gestión de los recursos. La identificación de procesos clave en un ecosistema, tales como las relaciones entre la ecología de determinadas especies con sus hábitats esenciales, ofrece una posibilidad para avanzar hacia la aplicación de la EBM sin tener que alcanzar el desarrollo de modelos super-complejos que aborden todos los procesos que ocurren en un ecosistema. Los diferentes estudios desarrollados a lo largo de esta tesis doctoral tienen dos objetivos principales. En primer lugar, la aplicación de nuevas técnicas y conceptos para la mejora de la caracterización de los hábitats esenciales de dos especies marinas localizadas en los estados superiores de la cadena trófica, el mero (Epinephelus marginatus, Lowe 1834) y el atún rojo del Atlántico (Thunnus thynnus, Linnaeus 1758). En segundo lugar, el desarrollo de nuevas metodologías, basadas en la información obtenida sobre hábitats esenciales, que permitan mejorar la evaluación y la gestión de las poblaciones de estas especies. Hoy en día, la conservación de las poblaciones explotadas del mero y el atún rojo se abordan desde enfoques técnicos bien diferenciados, en base a sus características ecológicas. El mero es una especie altamente residente que habita en fondos rocosos de los ecosistemas costeros del Mediterráneo. La conservación de sus poblaciones explotadas mediante el establecimiento de reservas marinas ha dado buen resultado. El atún rojo del Atlántico es una especie pelágica con una amplia distribución geográfica a lo largo de las aguas del Atlántico, que realiza largas migraciones durante la primavera para llegar a las áreas de reproducción, entre las que se encuentra el Mar Balear. La gestión de esta especie se basa, principalmente, en el establecimiento de tallas mínimas de captura y de cuotas de pesca a partir de la evaluación del estado de las poblaciones mediante la aplicación de modelos uni-específicos. En los últimos años la aplicación de técnicas procedentes de la ecología del paisaje terrestre (landscape ecology), en estudios de ecología en el medio costero ha dado lugar al inicio de la “ecología del paisaje marino”(seascape ecology). En los estudios desarrollados en el marco de este doctorado se han aplicado estas técnicas para mejorar la definición de los hábitats esenciales del mero y para identificar cambios en el uso del hábitat a lo largo de su desarrollo ontogénico. La mejora en la identificación de los hábitats esenciales del mero en diferentes etapas de desarrollo ha proporcionado información relevante sobre la ecología de esta especie y criterios para el diseño de áreas marinas protegidas más eficientes en cuanto a su conservación. Los resultados obtenidos durante el estudio de los hábitats esencial de mero, y la mejora en la caracterización de la estructura de los hábitats mediante la aplicación de medidas de paisaje marino, han proporcionado la base para el desarrollo de una metodología de diseño de áreas marinas protegidas en el marco de los programas de evaluación rápida (RAPs por sus siglas en ingles). En esta tesis doctoral se propone un método para la evaluación rápida de aéreas costeras desde un enfoque multidisciplinar. Este método proporciona herramientas para la selección, diseño y gestión de áreas marinas protegidas costeras cuando el factor tiempo, el presupuesto o la acción humana, ya sea solos o en combinación, crea una necesidad urgente de priorización. El esquema conceptual aplicado en el análisis de las relaciones entre la ecología del mero y sus hábitats esenciales y la transferencia de esta información a la mejora en la evaluación y gestión de esta especie, se ha adaptado al ambiente pelágico. La transferencia de ideas y técnicas de la ecología de paisaje marino al ambiente pelágico ha supuesto un reto a lo largo de este doctorado. Se han propuesto nuevas métricas de paisaje marino pelágico, que se han aplicado en el estudio de los habitats de reproducción del Atún rojo en aguas del Mar Balear, lo que ha permitido avanzar en el conocimiento de la ecología de esta especie y otras especies de túnidos. Estos avances han permitido el desarrollo de un modelo de predicción de la localización de las zonas de reproducción del atún rojo en Baleares, basados enteramente en la aplicación de datos procedentes de la oceanografía operacional (teledetección y modelos hidrodinámicos). Finalmente, la monitorización de los estadios larvarios del atún rojo y el análisis de sus hábitats esenciales han permitido desarrollar índices de abundancia larvaria, y demostrar que la información sobre hábitat mejora significativamente la evaluación de estos índices. Estos índices larvarios están permitiendo analizar la evolución de la población adulta de la población oriental del atún rojo del Atlántico, que se reproduce en el Mediterráneo.

Ecosystem-based management aims to provide a mechanism for achieving a consensus among multi-sectorial activities for sustaining goods and services and achieving ecological, economic and social objectives in an area. The present study adopts innovative methods and approaches aiming to promote a holistic approach towards collaboration and effective conservation management in Mediterranean Marine Protected Areas (MPAs). In order to understand the current management needs in the Mediterranean MPAs, a management effectiveness evaluation was conducted in the Mediterranean scale following an existing guide (Tempesta and Otero, 2013). Information was collected through a synthesis and integration of different approaches during the period 2013-2014, and MPA management was evaluated on the basis of 21 indicators that described the general categories: (i) management and legislation; (ii) conservation features; (iii) pressures; (iv) communication and outreach. Case studies were initially assessed separately and were finally compared in order to identify common challenges and good practices in MPA management that may be put forward. Some of the most important problems were the inadequate annual funding; limited surveillance and law enforcement; the inadequate stakeholder engagement and bottom-up approaches; policy gaps and long bureaucratic processes to take action; inadequate monitoring of ecological and socio-economic parameters; limited understanding of human activity threats and impacts along with defining critical thresholds that may assure good environmental status of marine ecosystems. We highly recommend that the evaluation be a cyclic process conducted by a neutral practitioner that will inform management decisions and that results should be disseminated in order to reach a high status of MPA management performance in the Mediterranean. The evaluation of MPA management effectiveness guided the next steps of the study towards addressing realistic MPA needs and providing suggestions to improve MPA management. We focused at Portofino MPA case study (Ligurian Sea, Italy) - the third smallest MPA in Italy hosting rich marine biodiversity and a significant amount of human activities. One of the future targets of the MPA’s consortium is to expand its area in order to improve its capacity to effectively protect vulnerable habitats and the species it hosts. Taking into account the past experience and the inadequate communication and up-to-date information in the area, this initiative is expected to raise conflicts and opposition from users. Hence, Portofino MPA represents a case study of particular interest and relevance with MPAs facing similar issues. Following a holistic methodological approach, an engagement process was carefully designed to provide an insight into the social networks’ characteristics directly involved in supporting stakeholder engagement for sound governance performance and co-management of resources. Enhancing stakeholder engagement from the beginning of the process is essential in order to holistically inform decisions and increase the efficiency of conservation management. It is widely accepted that stakeholder engagement may promote cooperation and the exploration of possible solutions to common problems; facilitate the mitigation of conflicts due to various interests; and enhance coordination and the enforcement of common rules in a more transparent way. A framework to examine structural patterns in social networks and identify central actors with the capacity to serve as communication hubs is suggested to boost information flow and enhance stakeholder participation in decision-making. The approach consists of two powerful tools, Stakeholder Analysis and Social Network Analysis, that their capacity to provide an in-depth knowledge of the complexity of social-ecological systems and the factors that influence the engagement process in MPA management has been recently identified. Identification of stakeholders and their relations in a social network, where information exchange and interaction occurs, may highlight important channels for communication, or indicate key stakeholders with the power to control information flow and influence perceptions. This information may be leveraged to accelerate behaviour, facilitate bridging between organisations, promote deliberation, and improve the diffusion of information in MPA management. The outcomes of the study showed that the social network of the Portofino MPA exhibits a core-periphery structure where some user groups seem to have more privileges regarding access to information and resources in the area. The core of the network keeps the network together, and central stakeholders have the capacity to act as communication hubs and facilitate a two-way information flow that will foster communication, trust and collective learning in natural resource management. However, more effort should be made towards strengthening relationships between actors that may influence or be influenced by decisions relating to the MPA. The adoption of alternative communication strategies that integrate visualisation and user-friendly web platforms, in parallel to personal communication are suggested to involve more actively marginalized actors into decisions, that will increase the network’s cohesion, mitigate the power of central actors and augment plurality and new ideas in the engagement process. Production and synthesis of quantitative and qualitative information, related to conservation features and human activities, is another important aspect in conservation management that negotiation and decisions will be based on. Management of small scale and recreational fishing is one of the most important concerns and challenges that Marine Protected Areas (MPAs) have to encounter from a socio-economic, cultural and ecological point of view. Monitoring and assessing fishing activity requires complicated approaches due to the heterogeneity of methods that combine different gears depending on the target species, the season and the characteristics of the area. Many standardized strategies of fisheries management have tried and failed to capture this spatial and temporal heterogeneity, or to provide improved understanding of fishing impacts on the ecosystem components. The present study developed a framework for the monitoring and mapping of recreational and artisanal fishing activity. The framework considers and may be adjusted depending on the MPA management capacity in terms of budget and technology available, personnel available, the level of trust that characterizes the relationship between the MPA and the fishermen, and the willingness of all relevant actors and authorities to provide or collate respectively information. Data from different monitoring strategies and sources were integrated to archive a complete dataset that described different fishing practices in the area. Simple spatial indicators that describe fishing effort were used to map and describe the footprint of each fishing practice on vulnerable habitats, and identify the areas that receive greater fishing pressure. However this is the first step in order to assess the impacts of fishing pressure on vulnerable habitats. Pressure-impact assessments were conducted using spatial analysis in order to holistically inform management decisions on vulnerable habitats such as coralligenous under pressure in Portofino MPA. The approach considers the cumulative impacts caused by different fishing practices and incorporates uncertainty regarding available information following the precautionary principle. Cumulative impacts are based on a conceptual model that identifies the pathways through which activities cause harm and describing the likelihood and consequences of an event. The vulnerability assessment quantifies these causal-chain links between biophysical attributes and to human stressors that are described in the conceptual models. The vulnerability informs on the potential risk of loosing (or degrading) a particular habitat due to a specific pressure, and can provide further support to the assessment of the cumulative impacts caused by different fishing practices operating in an MPA. Coralligenous communities, in terms of coverage, are more abundant in zone B, while Posidonia oceanica meadows dominate in zone C of Portofino MPA. However, a great percentage of the habitat lies outside the MPA borders, which confirms the desire of the MPA management board to expand the area. The areas that receive the highest amount of fishing effort were located between depths of 30-40 m receive the highest fishing pressure at the majority of zone B. The vulnerability assessment revealed that artisanal nets, and both recreational and artisanal bottom longlines, had the highest potential impact on coralligenous habitat, independently from the duration that are active on the seafloor. Other recreational activities that were considered to have high potential impact for coralligenous due to the destructive characteristics of the practice and gear used, or due to the pressure’s high intensity and frequency, were vertical jigging, bottom trolling and big game with a rod and reel. The cumulative impact assessment provided an in depth understanding of combined exposure-effect approaches and identified additional areas in zone C and in greater depths, that fishing activity is necessary to be managed more strictly. Several suggestions were enlisted in order to mitigate fishing impacts on coralligenous habitats, for instance the establishment of additional spatial and temporal closures, prohibition of destructive fishing practices, etc. while policy gaps were also identified in the current management system. The approach takes into account the heterogeneity of techniques and captures the different scale of impacts on benthic habitats in a systematic, transparent and repeatable way, and provides a useful tool that integrates ecological, management and policy interventions. An emerging threat in coastal MPAs is the loss of fishing gears that drift away driven by currents and finally end up on the seafloor covering in some cases a significant amount of fragile benthic habitats like coralligenous. In Portofino MPA this is reported as a common issue and frequently divers retrieve the lost gears and monitor it. To inform the MPA regarding which areas are more susceptible to lost fishing gear, a semi-quantitative spatial analysis was conducted using information from the sea-bottom morphology (depth, slope, Benthic Position Index, rugosity, curvature). The areas identified overlap spatially with areas of high fishing effort, while the local currents agree that most susceptible areas are located in the southern part of Portofino MPA. Although data quality regarding information coming from divers was poor, the suggested analysis may provide useful information in order to focus management actions on specific areas. Finally, the Marxan with Zones conservation planning model was applied on Portofino MPA’s present zoning plan in order to provide alternative solutions for the enlargement and re-zoning of the MPA. Different scenarios concerning the regulation of human activities such as fishing and diving activities taking place at different zones were developed. In our management plan, we set high level conservation targets based on relative EU Directives, the high conservation status of the Portofino MPA (SPAMI) and management objectives. In the present study preliminary results are shown for a single scenario where a 4-zone plan is suggested to the expanded surface area of the MPA, where diving and fishing activity are re-arranged in space and strictly regulated. The suggested zoning plan provided by MARXAN with Zones ensures that high conservation objectives are reached in Portofino MPA with the lowest possible operational cost. Overall, the present study aimed to provide a complete ecosystem-based management approach that considers the social and ecological drivers of the system as complementary components for supporting future conservation initiatives towards collaborative management of resources. The management suggestions of this study provide transparent, comprehensive and efficient plans that can improve the governance and the management of marine resources in the area. Innovative tools and methods were integrated to inform several aspects in the management of marine resources in order to promote a holistic approach towards collaboration and deliberation in MPA management. The developed methodology offers guidance on how to structure and focus efforts for collecting, synthesizing and analyzing of necessary information to inform holistically policymaking and management processes. Results provide useful advise in mitigating the cumulative impacts of human activities and deliver alternative solutions that are based on strict systematic conservation planning principles. Moreover, the study may assist the Portofino MPA to build the social conditions and a future engagement strategy where stakeholders will welcome the conservation initiative for its expansion, however particular effort should be made by the MPA management board towards this direction.

The goal of this research was to develop statistically robust ecosystem-based approaches, while optimizing data acquisition on relatively unexploited fish species in South Florida reefs, i.e., parrotfishes, Family Scaridae, in Biscayne Bay (with seasonal roller frame beam trawl surveys, 1996-2000) and Florida Keys (with annual Reef Fish Visual Censuses, 1997-2001), by following these steps: (I) analysis of information gaps for the stocks, including systematics, biogeography, population dynamics, reproductive ecology, trophodynamics, habitat use, and fisheries dynamics of Western Atlantic parrotfishes; (II) determination of primary research objectives from prioritization in Step I; (III) determination of essential fish habitats, ontogenetic shifts, migrations, and reef-seagrass habitat, from integration of stratified sampling design for fisheries-independent surveys, habitat selection theory-based analyses, and length-based analyses; (IV) estimation of population dynamics and fisheries-specific parameters encompassing life history demographics from empirical data or comparisons to theoretical expectations adapted to local conditions; (V) simulation modeling of a realistic range of fishing scenarios and demographic characteristics to evaluate the efficacy of potential traditional fisheries and spatial management strategies; and (VI) application of sampling optimization procedures and fisheries ecology approaches. Four scarid species had an estimated combined abundance of ca. 36.8 x 106 individuals in the Florida Keys. Connectivity among seagrass beds, coral reefs and deep waters had three major patterns: seagrass dwellers, reef dwellers, with inshore-to-offshore ontogenetic , and a seagrass-reef connection, using Biscayne Bay as an important recruitment ground. Marine protected areas of the Florida Keys National Marine Sanctuary did not show effects on abundance, size composition or spatial distribution of any parrotfish studied. Simulations suggested relatively short longevities (5-10 years), moderate body growth curvature, high instantaneous natural mortality rates (0.3-0.6 y super minus one), and low annual survival rates (27-54%). Simulated estimates of fishing mortalities ranged from 0.3 to 0.6 y super minus one, indicating low levels of exploitation, but low Spawning Potential Ratios (SPR = 23.5-26%). Proposed potential exploitation based on a legal minimum size equal to their size at first maturity and fishing rates equal or below to their natural mortality should secure SPR values at 45-48%.

La mise en place de l’approche écosystémique des pêches (AEP) requiert une amélioration de nos connaissances sur la complexité des écosystèmes. Comprendre la réaction de l’écosystème à des mesures de gestion est essentiel pour atteindre les objectifs de conservation. La modélisation écosystémique a amélioré nos connaissances sur le fonctionnement des écosystèmes et leurs interactions avec les usages du domaine maritime; et est de plus en plus utilisée pour évaluer l’impact de mesures de gestion. Le comportement de pêche des flottilles démersales françaises en Manche Orientale a été analysé. Les résultats montrent que les pêcheurs conservent leurs habitudes de pêches et que le trafic maritime peut impacter leurs décisions. Une analyse globale des résultats d’études menées au cours des trente dernières années démontre l’influence des habitudes et des espèces ciblées sur le comportement de pêche. L’exploration de la dynamique de l’écosystème a nécessité l’utilisation du modèle Atlantis, en focalisant sur deux espèces commerciales, la sole (Solea solea) et la plie (Pleuronectes platessa). L’importance des zones estuariennes est révélée, ainsi que le rôle joué par les rejets et par deux espèces clés, la morue (Gadus morhua) et le merlan (Merlangius merlangius). La sole et la plie ont peu d’influence sur le réseau trophique excepté sur la dynamique des invertébrés benthiques. Nous évaluons les conséquences de l’application de fermeture de zones et d’une réduction d’effort sur le comportement de pêche et l’écosystème et mettons en évidence un bénéfice de l’application combinée de ces mesures sur la biomasse des espèces commerciales et sur la valeur débarquée par unité d’effort
The implementation of the ecosystem approach to fisheries management (EAFM) requires an enhancement of our knowledge of ecosystem complexity. Understanding the ecosystem reaction to management regulation is a key to achieve conservation objectives. Ecosystem modelling improves our knowledge on ecosystem functioning in interaction with human activities, and it is now widely used to evaluate management strategies. The fishers’ behaviour of the French demersal fisheries in the Eastern English Channel (EEC) has been investigated. Results showed that fishers tended to adhere to past annual fishing practices and maritime traffic may impact on fishing decision. A global analysis of the fisheries science literature during the last three decades evidenced the influence of tradition and species targeting in fishers’ behaviour. The exploration of ecosystem dynamics required the use of the ecosystem model Atlantis with a focus on two commercial flatfish species, sole (Solea solea) and plaice (Pleuronectes platessa). The importance of estuary areas and of nutrient inputs has been revealed as well as the role of discards and of two key species, cod (Gadus morhua) and whiting (Merlangius merlangius). Sole and plaice did not have a strong influence on the trophic network excepted on the benthic invertebrates’ dynamics. Finally, we investigated the consequences of area closure and effort reduction on fishers’ behaviour and the ecosystem impacted. We observed a noticeable benefit of combining area closure and effort reduction on the biomass of most commercial species and on the total value landed per unit effort

Marine unconsolidated sediments constitute the largest ecosystems on earth in terms of spatial coverage, but there are still critical gaps in the science required to support conservation and ecosystem-based management. This is mainly due to the inaccessibility of these ecosystems in wave-exposed environments or deeper waters and the difficulty in observing biota in their three-dimensional sedimentary habitat. Currently, the physical driving processes of intertidal unconsolidated sediment ecosystems are much better understood than those of the subtidal ecosystems. However, these ecosystems are linked through water and sediment movement. This thesis, therefore, considers the continuum of unconsolidated sediment ecosystems across the entire continental shelf (i.e. intertidal to the shelf edge). The aim of this thesis was two-fold; (i) to advance the foundational understanding of biodiversity patterns and driving processes in unconsolidated sediment habitats, and (ii) to apply this knowledge in the development of a systematic conservation plan for marine unconsolidated sediment ecosystems. The South African west coast continental shelf was used as a case study in order to represent Eastern boundary upwelling regions. This study sought to investigate biodiversity patterns in macro-infaunal communities and determine their driving processes for incorporation into habitat classifications and the development of a habitat map. Systematic conservation plans require a map of biodiversity patterns and processes, and quantitative conservation targets to ensure representation of all biodiversity features including habitats.in marine protected areas. This thesis provided these key elements by classifying the unconsolidated sediment habitats and determining habitat-specific evidence-based conservation targets to support conservation of these important ecosystems. The application of these elements was then demonstrated in a systematic conservation plan for the unconsolidated sediment ecosystems of the South African west coast. Diversity patterns were examined using physical and macro-infauna data, ranging from the beach to the shelf edge (0-412 m). These data were analysed to develop two different habitat classifications, namely seascapes derived from geophysical and biophysical data, and biotopes derived from the combination of macro-infaunal and physical data. Multivariate analyses of 13 physical variables identified eight seascapes for the unconsolidated sediment samples from 48 sites on the South African west coast. These were based on depth, slope, sediment type, and upwelling-related processes (i.e. maximum chlorophyll concentration, sediment organic carbon content and austral summer bottom oxygen concentration). Latitude and bottom temperature were not considered major drivers of seascapes on the west coast because latitude closely reflected changes in upwelling-related processes and the temperature range was narrow across the shelf. This study revealed that productivity, a biophysical variable not usually included in geo-physical habitat classifications, played a significant role in the definition of seascapes on the South African west coast. It is therefore recommended that productivity be included in future seascape classifications to improve the utility of these classifications particularly in areas of variable productivity. Seascapes should, however, be tested against biological data to improve the understanding of key physical drivers of communities in unconsolidated sediment ecosystems. Macro-infaunal community distributions were determined along with their physical drivers for the unconsolidated sediments of the South African west coast. A total of 44 828 individuals from 469 taxa were identified from 48 sites representing 46.2 m2 of seafloor. Seven distinct macro-infaunal communities were defined through multivariate analyses and their key characteristic and distinguishing species were identified. These communities reflected five depth zones across the shelf, namely beach, inner shelf (10-42 m), middle shelf (60-142 m), outer shelf (150-357 m) and shelf edge (348-412 m). The processes driving the community structure of these depth zones were postulated to be tides, wave turbulence, seasonal hypoxia, habitat stability and homogeneity, and internal tides and/or shelf break upwelling, with drivers listed in order of increasing influence with depth. The middle shelf was further separated into three distinct communities based on sediment type, sediment organic carbon content and frequency of hypoxia. Variations in water turbulence, sediment grain size, upwelling-related variables and riverine sediment input were identified as the likely primary drivers of macro-infaunal community patterns. This chapter culminated in the development of a biotope classification based on the combination of macro-infaunal communities and their physical habitats (i.e. biotopes). South Africa has developed an expert-derived National Marine and Coastal Habitat (SANMC) Classification System which is used as a biodiversity surrogate in ecosystem assessment and spatial planning. This thesis tested the validity of this classification and the data derived Seascape classification against macro-infauna species abundance and biomass data in an effort to determine how well the different classifications represent macro-infaunal diversity of the west coast. These two classifications were also compared to the Biotope classification which combines macro-infaunal communities with their physical habitats. A canonical analysis of principle coordinates (CAP) was utilised to test the success with which each sample was allocated to the relevant habitat type in each classification. The total allocation success for each classification was used as a measure of effectiveness in terms of representing biodiversity patterns. Both classifications had similar allocation successes of 89-92 percent and 92-94 percent for the Seascape and National Habitat Classification respectively, but either over- or under-classified the macrofauna communities. The Biotope classification had the highest allocation success (98 percent), therefore it is the most accurate reflection of the macrofauna biodiversity patterns on the west coast. A key finding of this study was the increasing accuracy of classifications from physically- to expert- to biologically-derived habitat classifications. In this thesis, the Biotope classification was deemed the best representative of biodiversity patterns and was therefore used to produce the Biotope map for use in spatial assessment and planning. The distinct depth patterns that emerged in both the Seascape and Biotope classifications highlighted the need for further investigation of the relationship between depth and biodiversity. Despite variability in macro-infaunal communities, a general unifying pattern in biodiversity across the shelf was sought. Three relationships between depth and species richness have been described in the literature; namely a unimodal pattern, a positively linear relationship with depth, and no relationship between depth and species richness. These hypotheses were tested on the west coast. Two different species richness metrics were utilised to test the depth-diversity relationship, namely observed species density (spp.0.2m-2) and estimated species richness (spp.site-1). Observed species density increased from the beach to the shelf edge (350 m), then decreased to 412 m. The decline may have been due to difficulty in detecting species at greater depths as a result of sampling challenges. The inclusion of an innovative extrapolative method for estimating species richness (the capture-recapture heterogeneity model) within the Bayesian statistical framework mitigated the effects of species detection heterogeneity and revealed that species richness actually increased continuously across the shelf from beach to shelf edge. Thus the general relationship between depth and species richness is positively linear on the west coast of South Africa The new macro-infauna dataset and biotope map provided the opportunity to develop the first habitat-specific evidence-based conservation targets for unconsolidated sediments of the west coast. Species-Area Relationship (SAR) based conservation targets were developed for the biotopes using a modification of the generally accepted methodology. The accepted methodology has three steps (i) the estimation of total species richness for each habitat using the Bootstrap asymptotic estimator, (ii) the calculation of the slope of the species area curve (i.e. the z-value), and (iii) the calculation of targets representing 80 percent of the species. The inclusion of an innovative extrapolative species richness estimator, the Multi-species Site Occupancy Model (MSOM) provided better species richness estimation than the more conventional bootstrap species richness estimator, even though both are based on species accumulation. The MSOM, applied in the Bayesian statistical framework takes detectability of a species into account.

La mise en place de l’approche écosystémique des pêches (AEP) requiert une amélioration de nos connaissances sur la complexité des écosystèmes. Comprendre la réaction de l’écosystème à des mesures de gestion est essentiel pour atteindre les objectifs de conservation. La modélisation écosystémique a amélioré nos connaissances sur le fonctionnement des écosystèmes et leurs interactions avec les usages du domaine maritime; et est de plus en plus utilisée pour évaluer l’impact de mesures de gestion. Le comportement de pêche des flottilles démersales françaises en Manche Orientale a été analysé. Les résultats montrent que les pêcheurs conservent leurs habitudes de pêches et que le trafic maritime peut impacter leurs décisions. Une analyse globale des résultats d’études menées au cours des trente dernières années démontre l’influence des habitudes et des espèces ciblées sur le comportement de pêche. L’exploration de la dynamique de l’écosystème a nécessité l’utilisation du modèle Atlantis, en focalisant sur deux espèces commerciales, la sole (Solea solea) et la plie (Pleuronectes platessa). L’importance des zones estuariennes est révélée, ainsi que le rôle joué par les rejets et par deux espèces clés, la morue (Gadus morhua) et le merlan (Merlangius merlangius). La sole et la plie ont peu d’influence sur le réseau trophique excepté sur la dynamique des invertébrés benthiques. Nous évaluons les conséquences de l’application de fermeture de zones et d’une réduction d’effort sur le comportement de pêche et l’écosystème et mettons en évidence un bénéfice de l’application combinée de ces mesures sur la biomasse des espèces commerciales et sur la valeur débarquée par unité d’effort
The implementation of the ecosystem approach to fisheries management (EAFM) requires an enhancement of our knowledge of ecosystem complexity. Understanding the ecosystem reaction to management regulation is a key to achieve conservation objectives. Ecosystem modelling improves our knowledge on ecosystem functioning in interaction with human activities, and it is now widely used to evaluate management strategies. The fishers’ behaviour of the French demersal fisheries in the Eastern English Channel (EEC) has been investigated. Results showed that fishers tended to adhere to past annual fishing practices and maritime traffic may impact on fishing decision. A global analysis of the fisheries science literature during the last three decades evidenced the influence of tradition and species targeting in fishers’ behaviour. The exploration of ecosystem dynamics required the use of the ecosystem model Atlantis with a focus on two commercial flatfish species, sole (Solea solea) and plaice (Pleuronectes platessa). The importance of estuary areas and of nutrient inputs has been revealed as well as the role of discards and of two key species, cod (Gadus morhua) and whiting (Merlangius merlangius). Sole and plaice did not have a strong influence on the trophic network excepted on the benthic invertebrates’ dynamics. Finally, we investigated the consequences of area closure and effort reduction on fishers’ behaviour and the ecosystem impacted. We observed a noticeable benefit of combining area closure and effort reduction on the biomass of most commercial species and on the total value landed per unit effort

Previous pulse-chase experiments have revealed a wide diversity of benthic response patterns to organic matter (OM) input depending on environmental setting, benthic community structure and experimental conditions i.e. quantity and quality of the added OM.  However, the mechanisms and interaction of environmental and biological factors that produce an observed response pattern are poorly understood. The present thesis set out to improve our current understanding on the set of parameters that determine benthic response patterns.  The core of this study was based on two pulse-chase experiments in two bathyal settings: the Faroe-Shetland Channel (FSC) and the SW Cretan slope in the E. Mediterranean (E. Med).  The sub-zero temperatures in the FSC enabled the observation of the benthic response in “slow-motion” and showed that the response is not static but instead might go through various “phases”.  In the warm E. Med, C processing rates were considerably lower compared to previous measurements in adjacent regions.  The discrepancy was attributed to the particularly refractory sedimentary OM at the sampling station with apparent consequences for the physiological state of the bacterial community.  Both experiments showed that bacterial metabolism and its regulation is a key factor determining the reaction of the benthic community to OM inputs.  This thesis provided further understanding on the short-term fate of organic C in deep-sea sediments but also raised certain issues that could be addressed in future studies.

The primary research problem addressed in this thesis is the development of a conceptual framework for a novel ecological economics risk measure called “ecosystem services value at risk” to guide sustainability, efficiency and fairness in the human use of natural ecosystems. Ecosystem services value at risk integrates ecosystem services valuation with financial value at risk to provide an estimate of a “worst likely loss” in ecosystem services under alternative policies. This new approach estimates the uncertainty around ecosystem services values from human activities. By framing the risk to ecosystem services in terms of loss, this risk measure conveys a more powerful message about the need to protect nature. The core elements of an ecosystem services value at risk framework are: ecosystem services valuation; total economic value; stochastic ecological resource use models; financial value at risk; intergenerational discounting; society’s time frame for evaluation; and decision rules. This research is multidisciplinary, drawing insights from ecological economics, finance, fisheries economics, ecological modeling and decision analysis. Ecosystem services value at risk is illustrated with marine examples, which are timely and critical. Marine ecosystems, which provide valuable and essential benefits to humankind, are being severely altered all over the world from overfishing, climate change, marine pollution and habitat destruction. The risk measure is shown to be meaningful by applying a stochastic Schaefer surplus production model to a well-studied marine example, Namibian hake. A case study of the collapsed Georges Bank yellowtail flounder further demonstrates its usefulness to marine policy evaluation. A simple risk measure based on the market values of catch provisioning services leads to selecting conservative harvest policies, ruling out high levels of fishing intensity. The non-market values of a second type of ecosystem service, the regulating services from conserved biomass, are next considered. Both values provide a distribution for a lower bound estimate of the ecosystem services value at risk for the marine ecosystem. Including regulating services allows even more precautionary strategies that favor conservation. The ecosystem services value at risk framework thus supports sustainability and ecosystem resilience, promising to help protect the flow of benefits from nature for current and future generations.

Connectivity is a major contributor to the overall dynamics of marine populations. However, it still remains challenging to describe connectivity on ecologically meaningful scales of time and space. This is a major impediment to evaluating the impacts of marine protected area with respect to fisheries management objectives. This dissertation brings together a wide array of spatial and connectivity information in the Gulf of Mexico (GOM) with the goal of 1) understanding the spatial distribution of fish populations and source-sink dynamics and 2) evaluating whether this information can be integrated, through a modeling framework, to identify closed areas that could be beneficial to fisheries management in the Gulf of Mexico. First, a generalized additive modelling (GAM) approach is used to describe the distribution of a large number of species groups (i.e. functional groups) across the Gulf of Mexico (GOM) using a large fisheries independent data set (SEAMAP) and climate scale (decades) oceanographic conditions. Next a numerical Lagrangian particle transport model was developed that incorporates two major connectivity processes; site specific larval production and oceanographic transport for an entire large marine ecosystem and over multiple years. The two components are then combined to develop larval dispersal patterns for the entire GOM and identify areas operating as larval sources and sinks. Last, this information is integrated into an end-to-end ecosystem model to evaluate effectiveness of closing source and sink areas for the management of reef fish fisheries. Closed area managemeny simlautions for reef fish indicated closing reef fish source areas, as opposed to sinks, in the GOM is most efficient method of increasing total biomass and yield. However, the impacts across individual functional groups were site specific. Ultimately, these simulations demonstrate the inclusion of connectivity information could improve fishery management objectives in an ecosystem context.

Notions of ‘wildness' are increasingly relevant to upland management discussions in the Scottish Highlands as several conservation-focused estates embrace a ‘wildland management ethos'. However, while a range of wildland conservation initiatives have embarked upon pathways towards ‘rewilding', this research demonstrates that, although members of this creative conservation movement are widely perceived to share a common vision, they prioritise markedly different wildland qualities. Through a series of triangulated phases, this research explores this ‘spectrum of wildness' and examines the conceptual coherence of wildland restoration discourses. Twenty semi-structured scoping interviews with key stakeholders associated with Scotland's wildest places provide the foundations for an adapted Delphi model, incorporating a Q-methodology study, which utilises insights from seventeen large upland land-holdings to interrogate the disparate discourses associated with Scotland's emergent wildland movement. A taxonomy of management approaches is presented based upon (i) different conceptions of ‘wildness', (ii) differing degrees of concern for ecological and cultural integrity, (iii) conflicting beliefs about the degree of management intervention appropriate and (iv) fundamentally divergent underlying environmental ideologies. A further twenty-three semi-structured interviews exploring wilderness restoration frameworks in the USA, New Zealand and parts of Europe provide an international perspective on Scotland's distinctive approach to wildland management and demonstrate the challenges of multi-dimensional wilderness frameworks which grow out of conflicting mandates; most notably, a critical faultline exists between restoring ‘wildness' (focussed on processes) and naturalness (focussed on endpoints). Given that practical tensions can arise from these different ideological perspectives, understanding and accommodating the social and cultural dimensions which shape multiple (re)wilding discourses is considered critical. As such, place-specific and endogenous social representations are called for, in which wild land is both a physical place and a cultural ideal, and in which (re)wilding comprises a heterogeneous mix of different wilds. This research also critically reflects upon how cultural landscapes with wild qualities present opportunities for rethinking the historical and cultural dimensions of established wilderness values. By exploring the framing of ‘wild' in Scotland's wildland initiatives, a postmodern wildlands narrative which negotiates the conceptual challenges of (re)wilding in a storied, cultural landscape is presented.

The work in this dissertation represents an attempt to investigate multiple temporal and spatial scales of inquiry relating to the variability of marine resources throughout the Gulf of Mexico large marine ecosystem (Gulf LME). This effort was undertaken over two spatial extents within the greater Gulf LME using two different time-series of fisheries monitoring data. Case studies demonstrating simple frameworks and best practices are presented with the aim of aiding researchers seeking to reduce errors and biases in scientific decision making. Two of the studies focused on three years of groundfish survey data collected across the West Florida Shelf (WFS), an ecosystem that occupies the eastern portion of the Gulf LME and which spans the entire latitudinal extent of the state of Florida. A third study was related to the entire area covered by the Gulf LME, and explored a 30-year dataset containing over 100 long-term monitoring time-series of indicators representing (1) fisheries resource status and structure, (2) human use patterns and resource extractions, and (3) large- and small-scale environmental and climatological characteristics. Finally, a fourth project involved testing the reliability of a popular new clustering algorithm in ecology using data simulation techniques. The work in Chapter Two, focused on the WFS, describes a quantitatively defensible technique to define daytime and nighttime groundfish assemblages, based on the nautical twilight starting and ending times at a sampling station. It also describes the differences between these two unique diel communities, the indicator species that comprise them, and environmental drivers that organize them at daily and inter-annual time scales. Finally, the differential responses in the diel, and inter-annual communities were used to provide evidence for a large-scale event that began to show an environmental signal in 2010 and subsided in 2011 and beyond. The event was manifested in the organization of the benthic fishes beginning weakly in 2010, peaking in 2011, and fully dissipating by 2012. The biotic effects of the event appeared to disproportionately affect the nighttime assemblage of fishes sampled on the WFS. Chapter Three explores the same WFS ecosystem, using the same fisheries-independent dataset, but also includes explicit modeling of the spatial variability captured by the sampling program undertaking the annual monitoring effort. The results also provided evidence of a disturbance that largely affected the nighttime fish community, and which was operating at spatial scales of variability that were larger than the extent of the shelf system itself. Like the previous study, the timing of this event is coincident with the 2010 Deepwater Horizon oil spill, the subsequent sub-marine dispersal of pollutants, and the cessation of spillage. Furthermore, the spatial models uncovered the influence of known spatial-abiotic gradients within the Gulf LME related to (1) depth, (2) temperature, and (3) salinity on the organization of daytime groundfish communities. Finally, the models developed also described which non-spatially structured abiotic variables were important to the observed beta-diversity. The ultimate results were the decomposition of the biotic response, within years and divided by diel classification, into the (1) pure-spatial, (2) pure-abiotic, (3) spatial-abiotic, and (4) unexplained fractions of variation. This study, along with that in Chapter Two, also highlighted the relative importance of the nighttime fish community to the assessment of the structure and function of the WFS, and the challenges associated with adequately sampling it, both in space and time. Because one focus of this dissertation was to develop low-decision frameworks and mathematically defensible alternatives to some common methods in fisheries ecology, Chapter Five employs a clustering technique to identify regime states that relies on hypothesis testing and the use of resemblance profiles as decision criteria. This clustering method avoids some of the arbitrary nature of common clustering solutions seen in ecology, however, it had never been rigorously subjected to numerical data simulation studies. Therefore, a formal investigation of the functional limits of the clustering method was undertaken prior to its use on real fisheries monitoring data, and is presented in Chapter Four. The results of this study are a set of recommendations for researchers seeking to utilize the new method, and the advice is applied in a case study in Chapter Five. Chapter Five presents the ecosystem-level fisheries indicator selection heuristic (EL-FISH) framework for examining long-term time-series data based on ecological monitoring for resources management. The focus of this study is the Gulf LME, encompassing the period of 1980-2011, and it specifically sought to determine to what extent the natural and anthropogenic induced environmental variability, including fishing extractions, affected the structure, function, and status of marine fisheries resources. The methods encompassed by EL-FISH, and the resulting ecosystem model that accounted for ~73% of the variability in biotic resources, allowed for (1) the identification and description of three fisheries resource regime state phase shifts in time, (2) the determination of the effects of fishing and environmental pressures on resources, and (3) providing context and evidence for trade-offs to be considered by managers and stakeholders when addressing fisheries management concerns. The EL-FISH method is fully transferrable and readily adapts to any set of continuous monitoring data.

Animal movement is a key biological process for the maintenance of ecosystem services, and a major concern for the conservation of biodiversity. The aim of movement ecology is to understand the causes and consequences of these movements, including the effect of internal and external factors and its ecological implications. This research field has rapidly grown in the last decades fostered by recent technological and analytical developments, and is making substantial contributions to conservation biology, such as allowing the incorporation of the spatial and temporal scales of movements into management policies to enhance their scope and efficiency. Marine protected areas (MPAs) are the most used tools to face the effects of anthropogenic impacts on marine ecosystems. They play a major role in restoring and conserving overfished fish populations, and also potentially enhancing fisheries yield in adjacent areas through the direct spillover of juvenile and adult individuals. However, in order to be effective and generate such benefits, MPAs must be designed according to the movement attributes of targeted species, but this information is still rarely available, specially in temperate regions. In the last decades, passive acoustic telemetry techniques have demonstrated to be a valuable tool to study the movements and behavior of fishes covering large spatial and temporal scales, but the acoustic nature of the signals and the large amounts of data that they provide entail a series of challenges for their analysis and interpretation. The main objective of this thesis is to characterize the movement ecology of coastal fishes in relation to MPAs. This constitutes a basic information on the biology of species, which is required to understand changes in populations and ecosystems driven by natural or human induced impacts, as well as to correctly evaluate the outcomes of management actions. Specifically, the movements of two species, the white seabream (Diplodus sargus) and the common dentex (Dentex dentex), were monitored using acoustic telemetry in the Medes Islands MPA (Catalonia, NW Mediterranean Sea). Both species play important ecological and economical roles, shaping the structure and functioning of biological communities through top-down controls, and being an important resource for local artisanal and recreational fisheries. Nevertheless, they present a contrasting biology (omnivorous vs. predator), and therefore, different conservation needs. Firstly, we characterized the general movement attributes of the two species, including their habitat requirements and space use and activity patterns, within zones with different protection levels of the MPA. Secondly, we studied the behavioral responses of the two species to environmental fluctuations, by adding environmental information (seawater temperature and wave height) to movement analysis. These behavioral responses provide essential information on the ecology of the species such as their resistance to perturbations. Thirdly, we characterized their movement behavior during the spawning season, describing, for the first time, the formation of spawning aggregations for both species. Finally, this thesis also has an important computational and numerical component. A special effort has been done to adapt and develop new methods to visualize and analyze acoustic telemetry data, specially to improve the space use estimations by incorporating the vertical dimension, in order to provide a more comprehensive view of complex movement patterns. By studying the movement ecology of these species, we provide general mechanistic insights to understand the effects of protection on coastal fish species, as well as to predict future changes in their populations derived from climate change. We specially highlight the importance of studying the movement ecology of diverse species in order to propose integrative and more efficient management actions.
Las áreas marinas protegidas (AMPs), son las herramientas de gestión más utilizadas para contrarrestar los impactos antropogénicos sobre los ecosistemas marinos y juegan un papel fundamental en la protección y restauración de las poblaciones de peces afectadas por la sobrepesca. Sin embargo, para ser efectivas y generar los beneficios que se esperan de ellas, las AMPs deben ser diseñadas en concordancia con los atributos de los movimientos de las especies de peces que se pretenden proteger, pero esta información no suele estar disponible. El principal objetivo de esta tesis es caracterizar, mediante técnicas de telemetría acústica, la ecología del movimiento de especies de peces costeros en relación a AMPs, mediante el estudio del movimiento de dos especies: el sargo común (Diplodus sargus) y el dentón (Dentex dentex), en la reserva marina de las islas Medas (Catalunya, Mediterráneo NO). Específicamente, se han caracterizado los patrones de movimiento y actividad generales de las dos especies, la presencia de respuestas comportamentales a fluctuaciones ambientales (temperatura y oleaje), y su comportamiento reproductor. Además, se ha hecho un esfuerzo especial en adaptar y desarrollar nuevas técnicas de análisis y visualización para datos de telemetría acústica, con el objetivo de mejorar las estimaciones del uso del espacio, incorporando la dimensión vertical, y de proporcionar una visión más exhaustiva de los complejos patrones de movimiento. Toda esta información es de gran aplicabilidad para la gestión de estas y otras especies costeras, así como para entender los cambios en las poblaciones y en los ecosistemas derivados del cambio global.

Los objetivos de la tesis fueron estudiar los factores que pueden explicar la variabilidad existente en la distribución e intensidad de la pesca artesanal en torno a una reserva marina (RM), valorar el efecto de la protección sobre la pesca y analizar y valorar los efectos bio-económicos de configuraciones alternativas de diseño y gestión. Los resultados revelaron que las embarcaciones artesanales calan más artes, de menor longitud, en zonas de elevada diversidad de hábitats. El rendimiento pesquero depende del nivel de protección, la distancia a la RM y la diversidad de artes por unidad de área. La protección está teniendo resultados positivos sobre las poblaciones de peces explotadas y beneficiando a la economía local. El aumento de superficie protegida, distribuido en varias reservas integrales en emplazamientos adecuados, distanciadas unas decenas kilómetros, más que la reducción del esfuerzo, tendría efectos positivos sobre el poblamiento de peces y la economía local.
The aim of the present work is to study the factors that may explain the variability in distribution and intensity of artisanal fishing around a marine reserve, evaluate the reserve effect and analyze and assess the biological and economic effects of alternative configurations of a marine protected area. The results revealed that artisanal vessels used more fishing gears, but shorter, in high habitat diversity areas. The fishing yield depends of protection level, distance to marine reserve and diversity of fishing gears per unit area. The protection measures have had positive results on exploited fish populations and in the local economy. The increase of protected area surface, distributed on several no take zones at appropriate locations, a few kilometers apart, more than the reduction of the fishing effort, would have positive effects on the population of commercial fishes and the local economy.

Coral reefs are suffering unprecedented declines in coral cover and species diversity. These changes are often associated with  substantial shifts in community structure to new dominant organisms. Ultimately, these “phase shifts” can be persistent and very difficult to return from. Building insurance against degradation and decreasing the likelihood of reefs undergoing shifts to undesirable states will require sustainable management practices that uphold coral reef resilience. This thesis consists of five papers that contribute new knowledge useful for managing the resilience of coral reefs, and other marine ecosystems. Paper I shows how the morphology of natural substrate (dead coral colonies) can significantly influence coral recruitment patterns. Paper II focuses on larval lipid levels, a key determinant of coral dispersal potential, in a common Caribbean coral (Favia fragum). It shows that i) lipid levels exhibit a significant, non-linear reduction throughout the larval release period of F. fragum and ii) exposure to a common pollutant (copper) could potentially lead to a more rapid lipid consumption in the larvae. Paper III presents a broader analysis of the different undesirable states a coral reef can shift to as a consequence of reef degradation. It concludes that different states are caused by different driving factors and that management must explicitly acknowledge this. Paper IV proposes a suite of resilience indicators that can help managers assess when a coral-dominated reef might be moving towards a shift to an undesirable state. These indicators capture key-processes occuring on different temporal and spatial scales and signal resilience loss early enough for managers to take appropriate measures. Finally, Paper V reviews the feedback loops that reinforce the undesirable states of five important marine ecosystems and suggests certain strategies that can ease the restoration back to healthier conditions. Managing these critical feedbacks will recquire monitoring the processes underpinning these feedbacks, breaking already established feedbacks loops through large-scale management trials and acknowledging transdisciplinary solutions that move management beyond the discipline of ecology
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 5: In progress.

Madagascar, a country whose extraordinary levels of endemism and biodiversity are celebrated globally by scientists and laymen alike, yet historically has received surprisingly little research attention, is the setting of the present dissertation. Here, I contribute to the need for applied research by: 1) focusing on the most intensely fished section of the Toliara Barrier Reef, the Bay of Ranobe; 2) characterizing the marine environment, the human population, and the fisheries; and 3) collecting the longest known time-series of data on fisheries of Madagascar, thereby providing a useful baseline for future analyses. In Chapter 1, the bathymetry of the Bay was characterized following a unique application of the boosted regression tree classifier to the RGB bands of IKONOS imagery. Derivation of water depths, based on DOS-corrected images, following a generic, log-transformed multiple linear regression approach produced a predictive accuracy of 1.28 m, whereas model fitting performed using the boosted regression tree classifier, allowing for interaction effects (tree complexity= 2), provided increased accuracy (RMSE= 1.01 m). Estimates of human population abundance, distribution, and dynamics were obtained following a dwelling-unit enumeration approach, using IKONOS Panchromatic and Google Earth images. Results indicated, in 2016, 31,850 people lived within 1 km of the shore, and 28,046 people lived within the 12 coastal villages of the Bay. Localized population growth rates within the villages, where birth rates and migration are combined, ranged from 2.96% - 6.83%, greatly exceeding official estimates of 2.78%. Annual pirogue counts demonstrated a shift in fishing effort from south to the north. Gear and boat (pirogue) profiles were developed, and the theoretical maximum number of fishermen predicted (n= 4,820), in 2013, from a regression model based on pirogue lengths (R2= 0.49). Spatial fishing effort distribution was mapped following a satellite-based enumeration of fishers-at-sea, resulting in a bay-wide estimate of intensity equaling 33.3 pirogue-meters km-2. Landings and CPUE were characterized, with respect to finfish, by family, species, gear, and village. Expansion of landings to bay-wide fisheries yields indicated 1,885.8 mt year-1 of mixed fisheries productivity, with an estimated wholesale value of 1.64 million USD per annum.

In this thesis I investigated the status of the Mediterranean Sea ecosystem and the sustainability of its marine resources using an interdisciplinary approach, which combined data integration and modelling approaches. Results highlighted a series of commonalities for Mediterranean marine ecosystems: they indicate that ‘small pelagic fishes’, mainly European pilchards and anchovies, both with high biomasses and high proportions in catches, are important structuring species for the Mediterranean ecosystem (at regional, sub-regional and local scales). ‘Large pelagic fishes’ are the main keystone species for both the past and current Mediterranean ecosystem configuration, while ‘sharks’ and ‘medium pelagic fishes’ played a key role in the past, but their ecological role is currently replaced by benthopelagic and benthic cephalopods. In addition, the ‘Mediterranean monk seal’ “Monachus monachus”, where it still occurs, is the species with the highest TL followed by ‘piscivorous cetaceans’ and ‘large pelagic fish’. Looking at temporal ecosystem dynamics, biomass trends and ecological indicators (e.g., community biomass, trophic levels of the community, catch and diversity indicators) reveal that the combined effect of excessive fishing pressure and changes in primary productivity altered the Mediterranean marine ecosystem over time, especially reducing the proportions of top predators (e.g., pinnipeds, large pelagic fish) and mid trophic level organisms (e.g., small pelagic fishes) and increasing the abundance of groups at lower trophic levels (e.g., invertebrates). The Western and the Adriatic Seas are the most degraded ecosystems with biomasses declines among all the species compartments assessed (from forage fish to sharks/rays and skates, except for invertebrates that remained stable in time). The Ionian Sea was found to be the area with less biomass changes historically in comparison with available survey data. Even at a more local scale (Amvrakikos Gulf), both ecological indicators and biomass trends highlight a degradation of the demersal compartments of the food web but a relative stability of the pelagic ones mainly due to high eutrophication levels. Fishing pressure and changes in primary production (PP) play an important role in driving species temporal dynamics; yet, PP seems to be the strongest driver upon the Mediterranean Sea ecosystem. Fisheries data (mainly catch and effort) are found to be under-reported and under-estimated at regional, sub-regional and local scale. For example, fishing mortalities (and so landings data obtained from Food and Agriculture Organization [FAO] fisheries statistics) of three most important commercial species (European pilchard ‘Sardina pilchardus’, anchovy ‘Engraulis encrasicolus’ and hake ‘Merluccius merluccius’) were in fact observed in early decades (1950s), in all the Mediterranean sub-regions, between 5 and 10 times inferior from the average reference values reported in stock assessment for these fish stocks in the Mediterranean Sea. Even in the assessment of the Italian fisheries, the reconstructed of total catches were 2.6 times the landings officially reported by the FAO on behalf of Italy for the same period and same area, with unreported commercial landings (from both industrial and artisanal sectors) contributing 50% to the total catch (in relation to FAO reporting) and discards contributing another 7%. In Europe, several models and associated indicators exist that could be used in support of European policies (MSFD); yet, Ecopath with Ecosim (EwE) is the most applied tool for modelling marine and aquatic ecosystems and the one that can produce the largest number of indicators useful for the Marine Strategy Framework Directive (MSFD). Since anthropogenic pressures are rapidly expanding in the basin, this work constitutes an important first step to advance further in the regional assessment of the Mediterranean Sea ecosystem and to inform conservation plans and management actions.
En aquesta tesi he investigat l'estat ambiental del mar mediterrani i la sostenibilitat dels seus recursos marins mitjançant un enfoc interdisciplinari que combina la integració de dades i la modelització d'ecosistemes. Els resultats posen en relleu una sèrie de punts en comú dels ecosistemes marins mediterranis: el grup de "peixos pelàgics de mida petita", principalment compost per sardines i seitons, amb grans biomasses i captures, és un grup important en relació amb l'estructura de l'ecosistema mediterrani (tant a nivell regional, sub regional i a escales locals). El grup de “peixos pelàgics de gran mida” destaca per ser important com a grup clau de l'ecosistema, tant en el passat com en el present, mentre que el grup dels “taurons” i “peixos pelàgics de mida mitjana” han jugat un paper ecològic clau en el passat, però aquest és actualment reemplaçat pels grups de peixos bentopelàgicos i cefalòpodes bentònics. A més, el vell marí del mediterrani “Monachus monachus”, en aquelles zones on encara existeix, és l'espècie amb el nivell tròfic més alt, seguida pel grup de "cetacis que s'alimenten de peixos" i "peixos pelàgics de grans dimensions". Pel que fa a la dinàmica temporal de l'ecosistema, les tendències de la biomassa i dels indicadors ecològics (per exemple, la biomassa de la comunitat, els nivells tròfics de la comunitat, les captures i els indicadors de diversitat) revelen que l'efecte combinat d’una pressió pesquera excessiva i els canvis en la productivitat primària ha alterat l'ecosistema marí mediterrani a través del temps, especialment pel que fa a una reducció de les proporcions dels depredadors superiors (per exemple, pinnípedes, i peixos pelàgics de grans dimensions) i organismes de nivells tròfics mitjans (per exemple, peixos pelàgics de mida petita), i l'augment en abundància de grups d'organismes en nivells tròfics inferiors (per exemple, invertebrats). El mar mediterrani occidental i el mar adriàtic són els ecosistemes més degradats amb baixades de biomasses per a totes les espècies avaluades (des dels peixos pelàgics de mida petita als taurons i ratjades, amb excepció dels invertebrats que es mantenen estables en el temps). El mar jònic és l'àrea amb menys canvis històrics en termes de biomassa en comparació amb les dades disponibles de mostrejos. Fins i tot a una escala més local (en el Golf de Amvrakikos), tant els indicadors ecològics com les biomasses evidencien una degradació dels compartiments demersals de la xarxa tròfica, encara que s'observa una relativa estabilitat dels compartiments pelàgics, principalment a causa dels alts nivells d'eutrofització. La pressió pesquera elevada i els canvis en la producció primària (PP) juguen un paper important en la dinàmica temporal de les espècies; però, els canvis en la PP semblen ser els principals impulsors de la dinàmica temporal de l'ecosistema del mar mediterrani. Les dades pesquers (principalment la captura i l'esforç pesquer) es troben subestimats i conseqüentment registrats de forma errònia a escala regional, sub regional i local. Per exemple, la mortalitat per pesca (i per tant les dades de desembarcament que s'obtenen de les estadístiques de pesca de l'Organització per a l'Agricultura i l'Alimentació [FAO]) de tres de les espècies comercials més importants (Sardina europea “Sardina pilchardus”, anxova “Engraulis encrasicolus” i lluç “Merluccius merluccius”) per a les primeres dècades d'aquest estudi (1950), i en totes les sub regions mediterrànies analitzades, era entre 5 i 10 vegades inferior als valors de referència mitjana registrats en avaluacions de l'estoc d'aquestes poblacions al mar mediterrani. Fins i tot en l'avaluació de les pesqueries italianes, la reconstrucció de les captures totals mostra que les captures totals són 2,6 vegades més grans que els desembarcaments registrats oficialment per la FAO durant el mateix període i per la mateixa zona, amb desembarcaments comercials no declarats (dels sectors industrials i artesanals) que contribueixen al 50% de la captura total (en relació als informes de la FAO) i els descarts que contribueixen un altre 7%. A Europa hi ha diversos models i indicadors associats que podrien ser utilitzats en suport de les polítiques europees de gestió mediambiental, com la Directiva Marc sobre l'Estratègia Marina (MSFD); de totes formes, Ecopath with Ecosim (EwE) és l'eina més aplicada per a la modelització dels ecosistemes marins i aquàtics i la que pot produir un major nombre d'indicadors útils per a la MSFD. Atès que les pressions antropogèniques s'estan expandint ràpidament a la conca mediterrània, aquest treball constitueix un primer pas important per avançar en l'avaluació regional de l'estat ambiental de l'ecosistema marí mediterrani i per informar els plans de conservació i gestió presents i futurs.

Philosophiae Doctor - PhD
Ocean Governance in South Africa has gained momentum over the last decade with the publication of the Green and White Papers on the National Environmental Management of the Ocean in 2012 and 2014, and the promulgation of the Marine Spatial Planning Act in 2019. Parallel to this South Africa developed and implemented the Operation Phakisa Ocean Economy Development Programme and declared a network of twenty Marine Protected Areas. The timing of this study over the last five years allowed the opportunity to undertake a detailed study of the Ocean Governance Policy Development and Implementation as the formulation of the policy and its early implementation unfolded. The Study is primarily based on interpretation of the Green and White Papers as the primary and directed ocean governance policies produced by the Government of South African and the National Department of Environmental Affairs. It places these most recent specific ocean environmental policies in the context of the many other environmental policies that exits in the country.

[Truncated abstract] Selection of priority areas for Marine Park conservation is often compromised by the lack of comprehensive biodiversity data and the resources and expertise necessary to gain this information directly by sampling. One cost effective alternative is the use of species groups or indicator species as surrogates for total biodiversity. However use of these surrogates requires an ecological understanding of how they reflect biodiversity gradients. A framework for unravelling these relationships has been suggested that involves relating species biodiversity to different and competing ecological models using appropriate statistical analysis. I use this framework to explore coral species biodiversity over a range of environmental gradients encompassing the North West Shelf of Australia and the Great Barrier Reef in North East Australia. ... I assessed physiological responses of corals to physical factors to corroborate crossshelf patterns in species biodiversity. Finally, I investigated to what extent coral cooccurrence based species groups (or guilds) can be used as surrogates for total coral biodiversity. The major findings of this thesis were: i) coral biodiversity along cross-shelf environments was highly correlated to specific gradients of abiotic reef conditions; ii) larval modelling indicates the potential for significant connectivity across continentalshelf environments such that differences in species distribution are not simply as a result of self seeding. iii) similar correlative patterns were demonstrated for coral species that occur along comparable abiotic gradients in reef areas of both Eastern and Western Australia, suggesting a causal relationship between the physical environment and coral biodiversity; iv) coral physiological parameters measured using lipid fractions independently corroborated the hypothesis that there is a biological basis for observed coral distributions; v) reef coral communities are not highly structured across abiotic physical gradients and biodiversity across the shelf increases as conditions become suitable for a wider range of species; vi) total coral biodiversity can be estimated very accurately (within r2 values ranging from 0.75 to 0.90) using a small number (15-30) of optimally chosen indictor species using the randomForest statistical method. These results suggest coral biodiversity over cross-shelf environments conforms most closely to the

Face à l'intensification des pressions exercées par les activités humaines sur l'environnement marin, une organisation rationnelle de ces activités est nécessaire pour endiguer la dégradation des écosystèmes sur lesquels reposent l'approvisionnement en biens et services des sociétés humaines. Les concepts récents de l'approche écosystémique et leur prometteuse application à la planification spatiale maritime apportent des réponses à ce défi, mais la complexité du tissu formé par les écosystèmes marins et les usages humains interagissant avec rend difficile l'opérationnalisation de ces approches. Les travaux de cette thèse proposent de replacer la conservation des écosystèmes marins au cœur du processus de planification, par l'intégration des principes de la gestion écosystémique au sein de la planification spatiale maritime, et par l'évaluation du rôle des aires marines protégées (AMP) comme outil préférentiel pour la conservation des écosystèmes au sein du processus de planification. L'évaluation de l'impact cumulé des activités humaines à une échelle pertinente pour la gestion à Moorea, en Polynésie française, a permis de mettre en évidence la forte contribution des activités terrestres dans l'impact cumulé à l'échelle de lagon, soulignant la nécessité d'une gestion intégrée du continuum terre-mer. Nous démontrons ensuite la valeur ajoutée de cette même approche afin d'orienter de manière rationnelle et transparente les décisions de gestion et notamment la contribution des AMP à effectivement réduire les pressions humaines en leur sein. En effet, les AMP sont un outil de zonage préférentiel pour la conservation des écosystèmes marins et s'intègrent ainsi dans la planification spatiale maritime, à condition de gérer efficacement les activités responsables de pressions délétères sur le milieu. Nous avons utilisé un système de classification des AMP basé sur les activités régulées ou non en leur sein pour évaluer le niveau de protection réel des AMP en France et en Mer Méditerranée. Les résultats indiquent que, même si certains pays ont atteint les objectifs de 10% d'AMP en 2020, la grande majorité des AMP ne présentent pas de niveaux de protection suffisants pour délivrer des bénéfices socio-écologiques. Afin de s'assurer que les AMP puissent remplir leur rôle dans la conservation des écosystèmes, les objectifs récemment fixés pour 2030 fixent désormais 10% de protection stricte ou forte. Dans cette optique, nous analysé quels facteurs expliquent la présence des plus hauts niveaux de protection en Mer Méditerranée, et les résultats montrent les hauts niveaux de protection en Mer Méditerranée sont opportunistes et ne ciblent ni une biodiversité remarquable, ni des niveaux de pressions humaines élevés. Considérés ensemble, les résultats des différents chapitres mettent en lumière le manque de considération des objectifs de conservation, que ce soit au sein du MSP, par un manque d'approches dédiées localement à l'évaluation de l'impact cumulé des activités humaines et d'évaluation de différents scénarios de planification au regard des enjeux de conservation, et au sein des AMP, pourtant dédiées à l'atteinte de ces objectifs de conservation. Au-delà d'apporter ce constat, les différentes approches proposées ici permettent de replacer la biodiversité au cœur de la planification de l'espace marin
As the pressures exerted by human activities on the marine environment intensify, a rational organization of these activities is needed to stem the degradation of the ecosystems on which the supply of goods and services to human societies depends. Recent concepts of the ecosystem approach and their promising application to maritime spatial planning provide answers to this challenge, but the complexity of the tissue formed by marine ecosystems and the human uses interacting with them makes it difficult to operationalize these approaches. This thesis proposes to put marine ecosystem conservation back at the heart of the planning process, by integrating the principles of ecosystem-based management into maritime spatial planning, and by assessing the role of marine protected areas (MPAs) as a preferred tool for ecosystem conservation within the planning process. Assessing the cumulative impact of human activities at a scale relevant to management in Moorea, French Polynesia, has highlighted the strong contribution of land-based activities to cumulative impact at lagoon scale, underlining the need for integrated management of the land-sea continuum. We then demonstrate the added value of this same approach in guiding management decisions in a rational and transparent way, and in particular the contribution of MPAs to effectively reducing human pressures within them. Indeed, MPAs are a preferential zoning tool for the conservation of marine ecosystems, and can thus be integrated into maritime spatial planning, provided that the activities responsible for deleterious pressures on the environment are effectively managed. We used an MPA classification system based on regulated and unregulated activities to assess the actual level of protection afforded by MPAs in France and the Mediterranean Sea. The results show that, although some countries have achieved the target of 10% MPAs by 2020, the vast majority of MPAs do not have sufficient levels of protection to deliver socio-ecological benefits. In order to ensure that MPAs can fulfill their role in ecosystem conservation, the recently set targets for 2030 now set 10% of strict or strong protection. We therefore analyzed which factors explain the presence of the highest levels of protection in the Mediterranean Sea, and the results show that the high levels of protection in the Mediterranean Sea are opportunistic, targeting neither particular biodiversity components nor high levels of human pressure. Taken together, the results highlight the lack of consideration given to conservation objectives, both within the MSP, through a lack of approaches dedicated locally to assessing the cumulative impact of human activities and evaluating different planning scenarios with regard to conservation issues, and within the MPAs, which are nonetheless dedicated to achieving these conservation objectives. the various approaches proposed here make it possible to place biodiversity back at the heart of marine spatial planning

The South African coastal and marine environment is an essential ecologic and economic asset. Its associated services and products are substantially contributing to economic growth and sustainable development of the country. However, it is internationally and nationally recognised that land-based marine pollution (LBMP) is the most important single risk to the health and sustainability of coastal and marine waters and the associated ecosystems. The regulation of LBMP at the national level is still difficult and challenging. The issue of LBMP management has only recently been introduced in South Africa with the development of the National Programme of Action to Protect Marine Environment from Land-based Activities, 2008. South Africa is only starting to consider the question of LBMP regulation. This thesis aims to conduct a critical analysis of the South African regulatory framework pertaining to LBMP in comparison to international best practice and the French regulatory framework, in order to identify the key South African challenges in this regard and to make recommendations to address them. In order to do so, this research commences by providing an analysis of LBMP and the theoretical foundations associated with LBMP regulation, as promoted by international best practice. The study identifies and assesses the main regulatory features to be considered in the development, implementation and/or assessment of a regulatory framework pertaining to LBMP. These features will form the methodological framework to conduct the comparative legal assessment between the French and South African regulatory frameworks pertaining to LBMP. This thesis then provides a detailed and thorough legal analysis of the French and South African regulatory frameworks pertaining to LBMP using the methodological framework developed using guidance from international best practice. Finally, based on lessons learnt from the comparative legal study, this study concludes with a set of recommendations for the South African context.
Thesis (LL.D.)--North-West University, Potchefstroom Campus, 2011.

The development of human societies rests on functioning ecosystems. This thesis builds on integrated theories of linked social-ecological systems and complex adaptive systems to increase the understanding of how to strengthen the capacity of ecosystems to generate services that sustain human well-being. In this work, I analyze such capacity in human-dominated production ecosystems in Tanzania and Madagascar, and how this capacity is related to local management practices. Resilience of social-ecological systems refers to the capacity to buffer change, to re-organize following disruption, and for adaptation and learning. In Papers I and II, qualitative interview methods are used for mapping and analyses of management practices in the agroecosystem of the Mbulu highlands, Northern Tanzania. Practices such as soil and water conservation, maintenance of habitats for pollinators and predators of pests, intercropping, and landscape diversification, act to buffer food production in a variable environment and sustain underlying ecological processes. The practices are embedded in a decentralized but nested system of institutions, such as communal land rights and social networks, that can buffer for localized disturbances such as temporary droughts. Paper II compares these findings with practices in a farming system in Sweden, and suggests that similar mechanisms for dealing with uncertainty and change can exist in spite of different biophysical conditions. In Papers III and IV, interviews are combined with GIS tools and vegetation sampling to study characteristics and dynamics of the dry forests of Androy, southern Madagascar. Paper III reports on a previously underestimated capacity of the dry forest of southern Madagascar to regenerate, showing areas of regeneration roughly equal areas of degenerated forest (18 700 ha). The pattern of forest regeneration, degradation, and stable cover during the period 1986-2000 was related to the enforcement of customary property rights (Paper III). Paper IV reports on a network of locally protected forest patches in Androy that is embedded in a landscape managed for agricultural or livestock production and contributes to the generation of ecosystem services and ecosystem resilience at a landscape scale. Forest protection is secured by local taboos that provide a well-functioning and legitimate sanctioning system related to religious beliefs. In Paper V, two spatial modeling tools are used to assess the generation of two services, crop pollination and seed dispersal, by the protected forest patches in southern Androy. The functioning of these services is dependent on the spatial configuration of protected patches in the fragmented landscape and can be highly vulnerable to even small changes in landscape forest cover. In conclusion, many of the identified practices are found to make ecological sense in the context of complex systems and contribute to the resilience of social-ecological systems. The thesis illustrates that the capacity of human-dominated production ecosystems to sustain a flow of desired ecosystem services is strongly associated with local management practices and the governance system that they are embedded in, and that, contrary to what is often assumed, local management can and does add resilience for desired ecosystem services. These findings have substantial policy implications, as insufficient recognition of the dynamics of social-ecological interactions is likely to lead to failure of schemes for human development and biodiversity conservation.

Östersjön omfattas av en stor mångfald marina ekosystemtjänster som livnär närliggande samhällen. Deras funktion är hotad av en mängd terrestra och akvatiska aktiviteter som har förorenat havet, vilket kräver en långsiktig hållbar förvaltning. Syftet med denna uppsats är att bidra med kunskap om och förstå utmaningar och möjligheter i att uppnå en god ekologisk status i Östersjön. Studien baseras på en granskning av förvaltningsmetoder hos länsstyrelser och kommuner i två områden som är skyddade av den regionala överenskommelsen Helsingforskonventionen; Höga Kusten i Västernorrland och S:t Anna-Missjö i Östergötland. Till grund för det analytiska ramverket ligger Havs- och vattenmyndighetens rapport, som beskriver ekosystemtjänster som Östersjön bidrar med, samt även tjänsternas status, åtgärder och utmaningar som uppstår vid förvaltning. Resultatet baseras på kvalitativa metoder för att samla in data, genom att specifikt studera dokument samt intervjuer med lokala tjänstemän. Den insamlade empirin har blivit kategoriserad och analyserad i linje med Havs- och vattenmyndighetens rapport, därefter har innehållet diskuterats. Resultatet visar att mest fokus lades på hantering av övergödning, ohållbart fiske och reglering av föroreningar, samt deras trade-off- och synergieffekter som påverkar förvaltningen av just dessa ekosystemtjänster. Följaktligen, är det nödvändigt för tjänstemän att samverka med lokalbefolkningen för att uppnå en hållbar förvaltning av de skyddade områdena och deras ekosystemtjänster. Generella utmaningar ansågs vara tid, resurser och kunskap för förvaltning av marina miljöer. Dock genomsyrar myndighetens ramverk om ekosystemtjänster stora delar av länsstyrelserna och kommunernas arbete med marin förvaltning på Höga Kusten och S:t Anna-Missjö. Ekosystemtjänsternas status och funktioner är integrerade i länens och kommunernas förvaltningsmetoder av de skyddade områdena. Ekosystemtjänster som begrepp är däremot frånvarande och inte explicit nämnt i arbetet.
The Baltic Sea offers a diversity of marine ecosystem services which is providing support to nearby human communities. Their functions are jeopardized by terrestrial and aquatic activities which have heavily polluted the sea, necessitating long-term sustainable management. The aim of this bachelor thesis is to provide a scientific contribution to understanding the challenges and opportunities for reaching a good ecological status in the Baltic Sea, as well as insight into the ongoing management practices of Swedish county administrative boards and municipalities. Practices that involve conserving ecosystem services in two different marine protected areas the High Coast and St. Anna-Missjö, both of which have been designated important by a regional convention; the Helsinki Commission. Therefore, the Swedish Agency for Marine and Water Management has adopted a report on which ecosystem services the Baltic Sea provides, and the status of the services in different parts of the sea. This study is based on qualitative methods to gather data by a thorough reading of documents written by the counties and semi-structured interviews of local officials. The data has summarily been categorised and analysed in line with the national agency’s report, then discussed afterwards. The results show that the management practices were heavily emphasised on dealing with activities that lead to eutrophication, unsustainable fishery as well as regulation of polluting substances; where trade-offs and synergy-effects converge that impacts the management of other marine ecosystem services. Hence, it is necessary for officials to network with locals to have sustainable management of the protected areas and their ecosystem services. The officials pointed to the presence of a lack of time, resources and expertise in managing marine environments. Although the agency’s perspective on marine ecosystem services permeates large parts of county administrative boards and municipalities' work with marine management in the High Coast and St. Anna-Missjö. The status and functions of ecosystem services are integrated in their management practices of the protected areas. However, the concepts themselves are more absent and not mentioned explicitly.

In recent years, society has begun to take a new view of its relations with the surrounding environment, and in particular has become aware of the need to ensure the sustainability of the oceans and their biodiversity. This concerns have also moved the scientific community to include aspects of environmental science and engineering in their curricula. This thesis links both the causes and effects of maritime transport with the necessary protection of marine resources aiming to justify a specific proposal that would allow the right balance between the needs of maritime transportation and the desired environmental protection of the Strait of Gibraltar and the Gulf of Cadiz. Recent studies show that the model of human activity in this area is hardly sustainable in the terms in which has occurred to date and conclude that continuing with the current rate of growth of these activities would result in environmental problems leading to decreased levels of quality of life and a weakness of the productive sectors. It has also been demonstrated that the effects of chronic discharges in areas adjacent to the Strait of Gibraltar are more damaging than large spills even though limited in time, as occurred in the aftermath of the Prestige accident. Shipping is one of those human activities that have an ongoing impact on the marine environment and is capable of generating acute risks of serious environmental and economic consequences to the region. For these reasons, other Spanish waters enjoy some degree of protection against threats arising from shipping: the Mediterranean Sea is a Special Area under MARPOL Convention; the Cantabrian Sea and the north-western Atlantic waters are part of the Western European PSSA; and the Canary Islands were also designated as PSSA were several protective measures have been implemented. The designation of a Particularly Sensitive Sea Area (PSSA) represents a major advance in environmental protection that complements other existing conservation strategies. It is striking to note that despite the fact that the area subject to study supports one of the largest maritime traffic intensities of the planet and includes important spaces of environmental conservation - including UNESCO's Biosphere Reserves-, lacks an adequate level of protection to minimize the risks of marine pollution. In summary, this thesis studies the characteristics of the maritime area of the Strait of Gibraltar and the Gulf of Cadiz, as well as the levels of protection against the risks arising from shipping. A thorough analysis of the different options offered by international regulations to improve the aforementioned levels of protection leads to the conclusion that it would be appropriate to formally designate the area as a PSSA. Consequently, the dissertation postulates a detailed and definitive proposal for the designation of the PSSA STRAIT OF GIBRALTAR AND GULF OF CADIZ including various associated protective measures that could be implemented to improve safety of navigation, thus reducing the impact that maritime activities pose on the marine environment. The proposals put forward may also constitute a case study on how to combine science and engineering to achieve an environmental objective. In particular, Chapter 5 forms the basis for an eventual formulation of the proposed PSSA to the International Maritime Organization (IMO). Finally, the thesis provides lines of future research on further protection of the proposed PSSA. As a result, in addition to its value in the academic context, the work undertaken could materialize into concrete proposals that would contribute to the transfer of knowledge to the advantage of economic and social development through implementation of the academic research. This indeed contributes to the achievement of the UPC's own driven general strategies, as well as the enacted goals of the Campus of International Excellence of the Sea in the territorial context of the area covered by this thesis.
Esta tesis estudia las características del litoral y de las aguas marítimas de la zona del Estrecho de Gibraltar y Golfo de Cádiz, así como los niveles de protección frente a los riesgos derivados de la navegación y otras actividades marítimas en esa zona. Tras analizar detalladamente las diferentes opciones que ofrece la normativa internacional para mejorar los referidos niveles de protección, se concluye que resultaría adecuada la designación por parte de la Organización Marítima Internacional de esas aguas como Zona Marina Especialmente Sensible (ZMES) de acuerdo con las disposiciones del Convenio MARPOL. Consecuentemente, el trabajo personal de planteamiento de la tesis aporta una propuesta concreta para la designación de la ZMES del ESTRECHO DE GIBRALTAR Y GOLFO DE CÁDIZ que constituye el objeto principal de la tesis. Finalmente, a través de metodologías de selección de criterios, se diseña un sistema de ordenación de tráfico marítimo para la zona designada, que incluye distintas Medidas de Protección Asociadas que podrían implantarse para mejorar la eficiencia y los niveles de seguridad de la navegación reduciendo por tanto el impacto de las actividades marítimas sobre el medio marino

In recent years, society has begun to take a new view of its relations with the surrounding environment, and in particular has become aware of the need to ensure the sustainability of the oceans and their biodiversity. This concerns have also moved the scientific community to include aspects of environmental science and engineering in their curricula. This thesis links both the causes and effects of maritime transport with the necessary protection of marine resources aiming to justify a specific proposal that would allow the right balance between the needs of maritime transportation and the desired environmental protection of the Strait of Gibraltar and the Gulf of Cadiz. Recent studies show that the model of human activity in this area is hardly sustainable in the terms in which has occurred to date and conclude that continuing with the current rate of growth of these activities would result in environmental problems leading to decreased levels of quality of life and a weakness of the productive sectors. It has also been demonstrated that the effects of chronic discharges in areas adjacent to the Strait of Gibraltar are more damaging than large spills even though limited in time, as occurred in the aftermath of the Prestige accident. Shipping is one of those human activities that have an ongoing impact on the marine environment and is capable of generating acute risks of serious environmental and economic consequences to the region. For these reasons, other Spanish waters enjoy some degree of protection against threats arising from shipping: the Mediterranean Sea is a Special Area under MARPOL Convention; the Cantabrian Sea and the north-western Atlantic waters are part of the Western European PSSA; and the Canary Islands were also designated as PSSA were several protective measures have been implemented. The designation of a Particularly Sensitive Sea Area (PSSA) represents a major advance in environmental protection that complements other existing conservation strategies. It is striking to note that despite the fact that the area subject to study supports one of the largest maritime traffic intensities of the planet and includes important spaces of environmental conservation - including UNESCO's Biosphere Reserves-, lacks an adequate level of protection to minimize the risks of marine pollution. In summary, this thesis studies the characteristics of the maritime area of the Strait of Gibraltar and the Gulf of Cadiz, as well as the levels of protection against the risks arising from shipping. A thorough analysis of the different options offered by international regulations to improve the aforementioned levels of protection leads to the conclusion that it would be appropriate to formally designate the area as a PSSA. Consequently, the dissertation postulates a detailed and definitive proposal for the designation of the PSSA STRAIT OF GIBRALTAR AND GULF OF CADIZ including various associated protective measures that could be implemented to improve safety of navigation, thus reducing the impact that maritime activities pose on the marine environment. The proposals put forward may also constitute a case study on how to combine science and engineering to achieve an environmental objective. In particular, Chapter 5 forms the basis for an eventual formulation of the proposed PSSA to the International Maritime Organization (IMO). Finally, the thesis provides lines of future research on further protection of the proposed PSSA. As a result, in addition to its value in the academic context, the work undertaken could materialize into concrete proposals that would contribute to the transfer of knowledge to the advantage of economic and social development through implementation of the academic research. This indeed contributes to the achievement of the UPC's own driven general strategies, as well as the enacted goals of the Campus of International Excellence of the Sea in the territorial context of the area covered by this thesis.
Esta tesis estudia las características del litoral y de las aguas marítimas de la zona del Estrecho de Gibraltar y Golfo de Cádiz, así como los niveles de protección frente a los riesgos derivados de la navegación y otras actividades marítimas en esa zona. Tras analizar detalladamente las diferentes opciones que ofrece la normativa internacional para mejorar los referidos niveles de protección, se concluye que resultaría adecuada la designación por parte de la Organización Marítima Internacional de esas aguas como Zona Marina Especialmente Sensible (ZMES) de acuerdo con las disposiciones del Convenio MARPOL. Consecuentemente, el trabajo personal de planteamiento de la tesis aporta una propuesta concreta para la designación de la ZMES del ESTRECHO DE GIBRALTAR Y GOLFO DE CÁDIZ que constituye el objeto principal de la tesis. Finalmente, a través de metodologías de selección de criterios, se diseña un sistema de ordenación de tráfico marítimo para la zona designada, que incluye distintas Medidas de Protección Asociadas que podrían implantarse para mejorar la eficiencia y los niveles de seguridad de la navegación reduciendo por tanto el impacto de las actividades marítimas sobre el medio marino

La surpêche affecte les structures et dynamiques de nombreux écosystèmes marins, ainsi que les services écosystémiques qui en dépendent. En réponse, scientifiques et gestionnaires plaident pour une gestion écosystémique des pêches, intégrant la complexité des écosystèmes exploités, et fondée sur des objectifs de durabilité écologiques comme économiques. Dans ce cadre, l'objectif de cette thèse est d'élaborer une approche écosystémique de la gestion des pêches, conciliant la préservation de la biodiversité et de la résilience des écosystèmes exploités avec le maintien d'une production et de profits élevés. Pour cela, nous développons des modèles bio-économiques de pêcheries mixtes, constituées d'espèces indépendantes ou en interaction trophique. Nous montrons que maximiser l'ensemble des captures ou des profits d'une pêcherie mixte peut menacer la biodiversité et la résilience des écosystèmes exploités, mais que des instruments économiques peuvent y remédier. L'aversion au risque en présence d'incertitude favorise aussi une réconciliation entre différents enjeux de gestion. Nous déployons ensuite des approches de gestion multi-critères, afin d'identifier les meilleures stratégies en termes écologiques et économiques. Les stratégies choisies dépendent des préférences des gestionnaires : favoriser la production suppose d'orienter la pêche vers les faibles niveaux trophiques, tandis que favoriser la biodiversité ou la résilience suppose d'orienter la pêche vers des niveaux trophiques plus élevés. Nous suggérons ainsi qu'une diversification du profil de pêche permettrait de concilier enjeux écologiques et économiques pour une gestion écosystémique et durable des pêches
Overfishing affects the structures and dynamics of many marine ecosystems, as well as the associated ecosystem services. To tackle this issue, many scientists and managers are calling for an ecosystem-based fisheries management, integrating the complexity of harvested ecosystems, and based on ecological and economic sustainability objectives. In that perspective, our aim is to build an ecosystem approach to fisheries management, reconciling biodiversity and resilience preservation with the maintenance of high yields and profits. To this aim, we develop bio-economic models of mixed fisheries, composed of species that are either independent or in trophic interactions. We show that maximizing the aggregate catches or profits of a mixed fishery can threaten the biodiversity and resilience of harvested ecosystems, but that economic instruments can address these issues. In uncertain systems, risk aversion also helps reconciling constrasting management goals. We then apply multi-objective management approaches to identify the best strategies from an ecological and economic point of view. Chosen strategies depend on managers' preferences: favoring production implies to focus harvest on small trophic levels, while favoring biodiversity or resilience implies to focus on higher trophic levels. We therefore suggest that diversified fishing patterns could allow reconciling ecological with economic objectives, in order to achieve a sustainable ecosystem approach to fisheries management

Les récifs coralliens sont l’écosystème marin le plus complexe, mais aussi le plus menacé par les perturbations croissantes liées aux activités anthropiques. Leur conservation représente un véritable défi. Alors que le maintien des récifs au plus proche de leurs configurations et dynamiques actuelles doit être privilégié, nous devons également nous préparer à une évolution rapide de leur fonctionnement et adapter réseaux et outils de suivis à cette nouvelle situation. Des avancées technologiques récentes ont permis l’émergence d’outils innovants qui pourraient permettre à court terme d’augmenter considérablement la résolution spatio-temporelle des suivis. Parmi eux, l’acoustique passive est en plein essor. L’objet de cette thèse a été d’affiner son cadre d’utilisation pour évaluer et suivre l’état écologique et le fonctionnement des écosystèmes coralliens. Des enregistrements des paysages sonores et des relevés écologiques (assemblages de poissons et habitat) ont été réalisés sur 31 récifs de pente externe autour de trois îles de l’Indo-pacifique avec des caractéristiques environnementales variables, incluant des pressions anthropiques contrastées. L’analyse des résultats obtenus avec différentes combinaisons de paramètres d’échantillonnage (bande de fréquences, moment du cycle journalier choisi pour réaliser l’enregistrement, durée des échantillons de son) a permis de sélectionner un protocole d’échantillonnage basé sur les deux types d’indices écoacoustiques les plus utilisés pour l’étude des récifs coralliens. Ce protocole permet la caractérisation rapide et fiable de l’état écologique des récifs. En se basant sur ces lignes directrices, la capacité de six indices écoacoustiques à évaluer des fonctions clé de l’écosystème corallien a ensuite été démontrée. En comparant les apports de l’acoustique passive et de données environnementales pouvant être collectées par télédétection, la plus-value de l’utilisation d’indices écoacoustiques pour prédire la structure des assemblages de poissons récifaux a été identifiée et quantifiée. Une application de l’approche écoacoustique au suivi continu d’un site isolé a mis en évidence le potentiel particulièrement important de l’acoustique passive comme outil d’appui à la gestion dans ce type de contexte. Face à l’ampleur et à la vitesse des changements climatiques annoncés, les méthodes de suivi employées aujourd’hui, basées sur la présence d’observateur in situ, seront vraisemblablement insuffisantes. Combinée à d’autres outils de suivi, l’acoustique passive pourrait contribuer à détecter rapidement les perturbations des écosystèmes, condition indispensable pour en comprendre les causes et mettre en œuvre des réponses rapides et adaptées
Coral reefs are the most complex of marine ecosystems, but also the most threatened by ecological disruption resulting directly or indirectly from human activities. Their conservation represents a huge challenge. While maintaining coral reefs as close as possible to their current configurations and dynamics is among the highest priorities, we must also prepare for rapid changes in their functioning and adapt monitoring tools and networks to this new situation. Recent technological advances enabled the emergence of innovative tools with the potential to drastically increase the spatio-temporal resolution of coral reef monitoring. Among these, Passive Acoustic Monitoring (PAM) is on the rise. The aim of this thesis was to improve and facilitate the use of PAM as a tool for the assessment and monitoring of coral reefs’ ecological states and functioning. Soundscape recordings and ecological surveys (reef fish assemblages and habitat) were performed at 31 outer reef slope sites around three Indo-Pacific islands with variable environmental characteristics, including contrasted anthropogenic pressures. Analysing the results obtained with multiple combinations of sampling settings (frequency bandwidth, time of sampling (day/night), and sample duration) allowed the selection of a sampling scheme based on the two types of indices mostly used in coral reef studies. This scheme enables a rapid and reliable categorisation of reef’s ecological states. Based on these sampling guidelines, the capacity of six ecoacoustic indices to evaluate coral reef key functions was demonstrated. By comparing the contributions of PAM and coarse environmental data that could be sampled remotely, the added value of using ecoacoustic indices to predict reef fish assemblage structure was identified and quantified. An application of ecoacoustics to the continuous monitoring of a remote site highlighted the strong potential of PAM as a supporting tool for managers in such context. In view of the amplitude and velocity of expected climatic changes, current observer-based monitoring methods are likely to be exceeded. Combined to other monitoring tools, PAM could contribute to promptly detect ecosystem disturbances, which is essential to understand their causes and put in place rapid and adapted responses