Dissertations / Theses on the topic 'Assessment and management of freshwater ecosystems'
To see the other types of publications on this topic, follow the link: Assessment and management of freshwater ecosystems.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 43 dissertations / theses for your research on the topic 'Assessment and management of freshwater ecosystems.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Wilson, Gregory B. "Ecosystem-Based Management of the Lake Erie Ecosystem: A Survey-Based Approach to Assessment of Management Needs." Kent State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=kent1302202900.
Full text
2
Browne, Samantha. "The role of acute toxicity data for South African freshwater macroinvertebrates in the derivation of water quality guidelines for salinity." Thesis, Rhodes University, 2005. http://eprints.ru.ac.za/174/.
Full text
3
Ayas, Ceren. "Decoupling Developmentalism-environmentalism: Human Nature Conceptualizations In Freshwater Ecosystems Management In Turkey." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12611182/index.pdf.
Full textAbstract:
Would it be possible to go one step further than proposing sustainable development as the ultimate answer where people live within nature harmoniously if natural resources were not managed by central authorities, who mostly are male, aged, middle-class bureaucrats? Bearing in mind that we have reached a stage where ecological credit crunch will define human&rsquos limits remarks for non-teleological and eco-friendly ways of conceptualizing the relationship between human beings and nature is explored with an emphasis of &lsquo
who&rsquo
that is local, female, young, social science-based, active in civil movement. The objective of conducting the research is to find out the ways why green approaches in social, political and economic spheres in Turkey are not integrated as a first step to decouple the antagonism in man&rsquo
s relationship with nature. The analysis tried to grasp the discrepancies of conceptualizing human-nature relationship in order to find out which segment of the society would be closer to adopt green values, with the intention of proposing them to be involved in a greater extent to decision-making mechanisms with regards to natural resources management, as well as an attempt to grasp the overall picture in understanding nature-human relationship in Turkey by focusing on wetland management based on the research conducted in Bafa Lake (Aydin), Uluabat Lake (Bursa), Salt Lake (Konya) and Egirdir Lake (Isparta). Thanks to the scale that is constructed by operationalizing the existing debates on environmental ethics, agents that would follow more ecologically sound discipline towards living harmoniously within nature is analysed.
4
Pereira, Ana Carina Santos. "Linking exposure of mediterranean freshwater ecosystems to pesticides mixtures with their environmental side-effects." Doctoral thesis, ISA, 2017. http://hdl.handle.net/10400.5/14958.
Full textAbstract:
Doutoramento em Engenharia do Ambiente - Instituto Superior de AgronomiaIn freshwater ecosystems associated with agricultural areas, organisms are exposed to a multitude of toxicologically and structurally distinct pesticides in concentrations that may fluctuate over time. However, the environmental risks of chemicals are traditionally evaluated and regulated on the basis of single substance. Understanding and improving the link between effects and exposure assessment is an important step in the current challenges of risk assessment in order to increase its ecological relevance. To this end, integrated approaches of different hierarchical levels of complexity and ecological realism have been developed and applied, including: exposure modelling, laboratory testing with individual organisms, species sensitivity distribution, ecosystem models and assessment of aquatic community interactions to evaluate the effects of realistic pesticide combinations on water bodies associated with rice, tomato and maize typical agroecosystems of Mediterranean conditions. Contributing to the overall knowledge of the adequacy of the prospective risk assessment and demonstrating that pesticide risk may be underestimated during the actual registration procedure. The data generated in the present study contributed to the derivation of optimized programs of measures under the scope of European legislation; the identification of sites with the highest expected impacts of pesticide mixtures; the evaluation of the major pesticide compounds that contributed mostly to the identified aquatic risks. Furthermore contribute to a deeper knowledge and unravel the effects of co-occurring chemicals, environmental and biological stressors in aquatic ecosystems considering the effects of biotic and abiotic interactions at community and ecosystem levels. The results contribute to reducing the risks of pesticides in freshwater
N/A
5
Damiani, Mattia. "Addressing water consumption impacts on freshwater ecosystems : development of a regionalized, global habitat-based model for life cycle impact assessment." Thesis, Montpellier, SupAgro, 2018. http://www.theses.fr/2018NSAM0013.
Full textAbstract:
Environ 65% des eaux intérieures sont menacées modérément ou fortement par l'altération anthropique et le changement climatique. La Terre a perdu environ la moitié de ses habitats d'eau intérieure au cours des cent dernières années et le prélèvement mondial d'eau devrait augmenter de plus de 50% au cours des 20 prochaines années. Dans ce contexte, la concurrence pour les ressources en eau entre les humains et les écosystèmes est appelée à s'intensifier au détriment de la biodiversité d'eau douce. Pour cette raison, il est aujourd'hui impératif de quantifier et de sauvegarder les besoins en eau de ces écosystèmesEn tant qu'outil global d'aide à la prise de décision, plusieurs modèles d'évaluation d'impact de la consommation d'eau sur les écosystèmes ont été proposés dans le cadre de l'analyse du cycle de vie (ACV). L'un des défauts importants des modèles actuels d'ACV, qu'ils soient mécanistes ou non-mécanistes, midpoint ou endpoint, c’est la prise en compte limitée des besoins environnementaux en eau (EWR). Pour cette raison, les approches existantes pour l'évaluation des EWR ont été étudiées, afin d'évaluer les avantages potentiels d'une meilleure prise en compte des principes écohydrologiques dans l’ACV sur les écosystèmesCela a permis de définir le concept d'habitat d'eau douce en ACV et d'élaborer un cadre conceptuel pour l'application des méthodes de simulation d'habitat dans la modélisation. Un indicateur midpoint du potentiel de changement d'habitat (HCP) évaluant l'impact de la modification du débit sur les habitats des poissons et des invertébrés dans les cours d'eau a été élaboré. Le nouveau modèle a été testé sur le réseau fluvial français à l'échelle du tronçon fluvial, en caractérisant le changement d'habitat en saison sèche et humide. Les HCP ont ensuite été agrégés à l'échelle du bassin versant. Après, le nouveau modèle a été généralisé pour permettre une extension globale. Les variables d'entrée du modèle HCP généralisé ont été calculées à partir des bases de données et des modèles existants sur une résolution mensuelle. Les limites, l'incertitude et les perspectives de recherche de la nouvelle approche ont finalement été discutéesApproximately 65% of inland waters are under moderate or high threat by anthropogenic alteration and climate change. Earth has lost around half of inland water habitats in the last hundred years and global water withdrawal is expected to increase by more than 50% within the next 20 years. In this context, competition for water resources between humans and ecosystems is set to rise at the expense of freshwater-dependent biodiversity. For this reason, nowadays it is imperative to quantify and safeguard water needs of freshwater-dependent ecosystems.As a global tool to support decision-making, in life cycle assessment (LCA) several models for life cycle impact assessment (LCIA) of water consumption on ecosystems have been proposed. One important flaw of current LCIA models, whether they are mechanistic or non-mechanistic, midpoint or endpoint-oriented, is their limited consideration of environmental water requirements (EWR). For this reason, existing approaches for EWR assessment have been investigated to evaluate potential benefits of better including ecohydrological principles in LCIA on ecosystems.This enabled the definition of the concept of freshwater habitat within the boundaries of LCIA and the development of a framework for the application of habitat simulation methods in LCIA modeling. A midpoint habitat change potential (HCP) indicator assessing the impact of flow alteration on instream habitats of fish and invertebrates was developed. The new model has been tested on the French river network at the river reach scale, characterizing habitat change in wet and dry seasons. HCPs were then aggregated at watershed scale. The new model was subsequently generalized to allow global extension. Input variables of the generalized HCP model have been calculated from existing databases and models on a monthly resolution. Limitations, uncertainty and research perspectives of the new approach are discussed
6
Valentine, K. Hope. "Methods in health assessment of freshwater mussels, Amblema plicata and Quadrula spp." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1293654676.
Full text
7
Uyizeye, Erasme. "Developing an Odonate-Based Index for Monitoring Freshwater Ecosystems in Rwanda: Towards Linking Policy to Practice through Integrated and Adaptive Management." Antioch University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=antioch158827000356307.
Full text
8
Nikolakopoulou, Myrto-Georgia. "The functional role of emergent macrophytes in nature-based solutions (NBS) aiming to mitigate nutrient loading in freshwater ecosystems." Doctoral thesis, Universitat de Barcelona, 2021. http://hdl.handle.net/10803/672904.
Full textAbstract:
Freshwater degradation has been largely attributed to excess nutrient concentrations of anthropogenic origin. Freshwater degradation in combination with water scarcity are the reason of severe stress on water resources globally. As one third of the world’s population does not have access to clean drinking water, nutrient pollution is imperative to be addressed. Nature-based solutions (NBS) is a recent concept to address several societal challenges, using techniques inspired by nature, or by nature itself, while preserving ecosystem sustainability. Water security is among the essential societal challenges that NBS can address, with nutrient pollution of freshwater systems being one of its primary aspects. While NBS projects aiming to address nutrient loading in freshwater systems, conspicuously include emergent macrophytes in their design, there is a lack in mechanistic understanding of how these aquatic plants enhance water treatment performance.
In the present doctoral thesis, we focused on bridging this knowledge gap by investigating the plants’ physical, chemical and biological influence on the subsurface aquatic environment and the implications for nutrient mitigation. Specifically, we examined subsurface solute transport and nutrient retention under the presence of three emergent macrophyte species; Iris pseudacorus L., Phragmites australis L., and Scirpus lacustris L., while we also explored the influence of dissolved organic carbon (DOC) quality on nitrogen cycling. To this aim, we performed a series of three studies in a setup of 12 artificial flumes, where we used traditional methods of stream ecology (i.e. pulse additions of conservative and reactive tracers) to characterize subsurface solute transport and to estimate nutrient spiraling metrics. Likewise, we experimentally modified DOC lability in the flumes, and we characterized root system architecture of the used emergent macrophytes.
Regarding the physical effect of macrophytes, our results showed that macrophytes root architecture can substantially influence subsurface solute
transport. Specifically, a dense root system of fine roots results in increased hydraulic retention, while an architecture of thicker roots leads to inverse results, facilitating infiltration. Further, we found that the chemical and biological influence of emergent macrophytes on the subsurface aquatic environment is species specific, and depends on physiological differences between the species, and on the plants’ capacity to create long residence times in the subsurface. Additionally, the presence of emergent macrophytes was found to facilitate N removal, while the availability of a labile C source mostly increased microbial respiration, rather than denitrification.
Finally, in the general discussion of the thesis, we discuss the above results and further synthesized them with information from the literature, within the context of NBS.
Overall, the present doctoral thesis elucidates some unclear aspects of the functional role of emergent macrophytes in NBS aiming nutrient mitigation, highlight the importance of suitable macrophyte species selection in NBS systems to optimize treatment performance, and provides valuable guidelines to NBS practitioners for successful macrophyte species identification.La degradació dels ecosistemes aquàtics s’ha atribuït, en gran mesura, a l’excés de concentracions de nutrients d’origen antropogènic. Aquesta degradació, combinada amb l’escassetat d’aigua, és la principal causa de l’alarmant problemàtica dels recursos hídrics a nivell global. Donat que un terç de la població mundial no té accés a aigua potable, es fa imprescindible abordar la problemàtica de la contaminació per nutrients. El concepte de solució basada en la natura (SBN) ha aparegut recentment per designar aquelles tècniques inspirades en la natura que aborden diversos reptes socials tot preservant la sostenibilitat dels ecosistemes. La seguretat de poder disposar d'aigua es troba entre els desafiaments socials més importants que avui dia afronten les SBNs, essent la contaminació per nutrients en ecosistemes aquàtics un dels seus principals objectius. Si bé els SBN destinats a abordar la problemàtica de la càrrega de nutrients en sistemes aquàtics incorporen macròfits emergents en el seu disseny de forma rutinària, hi ha una manca de coneixement dels mecanismes que expliquen com aquestes plantes aquàtiques milloren el tractament de les aigües. En aquesta tesi doctoral, ens hem proposat reduir aquesta mancança del coneixement investigant com els trets físics, químics i biològics de les plantes influeixen en el medi aquàtic subsuperficial i com afecten la mitigació de nutrients. Concretament, hem examinat el transport de soluts a la subsuperficie i la retenció de nutrients sota la presència de tres espècies de macròfits emergents; Iris pseudacorus L., Phragmites australis L. i Scirpus lacustris L.. Addicionalment, hem explorat la influència de la qualitat del carboni orgànic dissolt en el cicle del nitrogen. Per portar a terme aquest objectiu, es van realitzar una sèrie de tres treballs dissenyats amb una mateixa configuració de 12 canals artificials experimentals, i on es van aplicar mètodes tradicionals de l’ecologia fluvial (és a dir, addicions sobtades de traçadors conservatius i d’elements reactius) per poder caracteritzar el transport subsuperficial de soluts i estimar les mètriques de l’espiral de nutrients. Igualment, es va modificar experimentalment el grau de labilitat del carboni en el sistema de canals, i es va caracteritzar l'arquitectura del sistema radicular d’aquests tres macròfits emergents. Quant a l’efecte físic dels macròfits, els resultats demostren que l’arquitectura radicular dels macròfits influeix substancialment en el transport subsuperficial dels soluts. Concretament, un sistema dens d’arrels fines dóna lloc a una major retenció hidràulica, mentre que una arquitectura d’arrels més gruixudes condueix a resultats inversos, donat que faciliten la infiltració a nivell intersticial. A més, hem constatat que la influència química i biològica dels macròfits emergents en el medi subsuperficial aquàtic és específica de cada espècie, i depèn de les diferències fisiològiques entre elles, i de la capacitat de les plantes per crear major temps de residència en el medi intersticial. Addicionalment, hem provat que la presència de macròfits emergents facilita l’eliminació de nitrogen, mentre que la disponibilitat d’una font de carboni làbil fa augmentar la respiració aeròbica microbiana en lloc de la desnitrificació. Finalment, a la discussió general de la tesi, es discuteixen els resultats obtinguts i es sintetitzen dins del context de les SBN amb informació extreta de la bibliografia. En general, la present tesi doctoral posa de manifest aspectes poc coneguts sobre el paper funcional dels macròfits emergents quant a la reducció de nutrients en les SBNs. També posa en relleu la importància de fer una selecció adequada d’espècies de macròfits per a sistemes on s’apliquen SBN a fi d’optimitzar el tractament d’aigües; i proporciona valuoses pautes per a professionals que apliquen SBNs per tal d’identificar les espècies de macròfits més apropiades per la reducció de nutrients.
9
Ho, Chi-fai, and 何志輝. "Ecological risk assessment and management of invasive freshwater fish species from aquarium and ornamental trades in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/194580.
Full textAbstract:
Since globalization have promoted the ornamental trade and accelerated the movement of freshwater fishes around the world, non-native species pose a high potential to be released into local freshwater habitats, and to spread and establish as invasive and nuisance species with adverse ecological, economic and social impacts. This study aimed to investigate the potential of the ornamental freshwater fish trade as an invasion pathway in Hong Kong, assess the ecological risk of common aquarium freshwater fish species being traded in the local market, identify species of concern and recommend ways for their management with a view to minimizing biological invasion risk associated with the aquarium trade. Based on a series of systematic market surveys through visiting 46 major aquarium shops in Hong Kong, about 167 freshwater fish species were found in the local aquarium trade between summer 2012 and spring 2013. Twenty-five species were randomly selected to go through two standard ecological risk assessment protocols (i.e., FISK & IFRA). The assessment results indicated that the goldfish (Carassius auratus), common carp (Cyprinus carpio carpio) and Wel’s catfish (Silurus glanis) have a high invasive risk in Hong Kong. The ornamental trade is one of the significant sources of freshwater fish invasions in Hong Kong. An integrated invasive species management plan is recommended to apply and implement in Hong Kong. The key elements of this management plan include (1) development of law and regulation on invasive species, (2) establishment of an early detection programme (like the current study), (3) implementation of control and eradication measures, (4) setting up invasive species handling guidelines and (5) fostering public education programs on biological invasion prevention. The plan should involve the participation of all stakeholders, such as government, industry, social community organization and public in order to engage them to jointly effectively tackle and manage invasive species and thereby conserve Hong Kong’s aquatic biodiversity.published_or_final_version
Environmental Management
Master
Master of Science in Environmental Management
10
Figueroa-Cano, Maria Enedina. "Indicators for the assessment of the sustainability of anthropogenic ecosystems, a model development approach for watershed natural resources management." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq48572.pdf.
Full text
11
Weiss, Steven P. "Bioassessment of the West Branch of the Wolf River /." Link to full text, 2007. http://epapers.uwsp.edu/thesis/2007/weiss.pdf.
Full text
12
Mathie, Devan M. "Assessing an In-Situ Total Algae Sensor Fluorometer for Performance in Freshwater Estuaries." Kent State University Honors College / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1588015130835849.
Full text
13
Bliss, Kevin R. "An outcome-based assessment of the New York State Department of Environmental Conservation freshwater wetlands regulatory system in Central New York." Thesis, State University of New York Col. of Environmental Science & Forestry, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3628499.
Full textAbstract:
This dissertation evaluates freshwater wetland impact avoidance and mitigation resulting from the New York State Department of Environmental Conservation (NYSDEC) permitting program within Central New York. Concurrent with this, is an effort to ascertain wetland functionality through a rapid assessment approach to wetland evaluation. Three primary techniques were employed: First, NYSDEC permit decisions were compared to the NYSDEC Freshwater Wetland Regulation Guidelines on Compensatory Mitigation (NYSDEC 1993), to determine whether or not the Guidance was adhered to. Second, NYSDEC permit requirements were compared to the actual mitigation efforts conducted by a permittee in the field to determine whether or not the permittee complied with imposed requirements. And third, a rapid assessment approach comparing functions and values at wetland mitigation sites to the corresponding natural wetland that was impacted by NYSDEC permit issuance was used to determine whether or not the functions and values provided by the mitigation adequately replaced those lost at the original impacted wetland site. The results of this review indicate that the majority of wetland mitigation guidelines are not followed the majority of time. For example, less than one third of the time was mitigation based on plans providing short or long term goals or measurable performance criteria. Often permittees do not comply with imposed freshwater wetland permit requirements related to mitigation. More specifically, thirty five percent of the time, permit requirements for mitigation were not met for those files sampled. As for the functions and values being replaced, that is not happening with six out of nine measured functions: open space and aesthetic resources; erosion control; pollution treatment; protection of subsurface water resources; wildlife habitat; and flood control. The three functions found to be replaced by mitigation include recreation; sources of nutrients in freshwater food cycles and nursery grounds / sanctuaries for freshwater fish; and education and scientific research.
14
Reap, John J. "Plants in the garden an approach to modeling the impact of industrial activities in ecosystems /." Thesis, Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-04082004-201301/unrestricted/reap%5Fjohn%5Fj%5F200405%5Fmast.pdf.
Full textAbstract:
Thesis (M.S.)--Mechanical Engineering, Georgia Institute of Technology, 2004.Matthew J. Realff, Committee Member ; Farrokh Mistree, Committee Member ; Berdinus A. Bras, Committee Chair. Includes bibliographical references (leaves 191-195).
15
Wangai, Peter Waweru [Verfasser]. "Mapping and assessment of ecosystem services to improve resource management and human wellbeing in data-scarce peri-urban ecosystems / Peter Waweru Wangai." Kiel : Universitätsbibliothek Kiel, 2017. http://d-nb.info/1140054120/34.
Full text
16
Wangai, Peter W. [Verfasser]. "Mapping and assessment of ecosystem services to improve resource management and human wellbeing in data-scarce peri-urban ecosystems / Peter Waweru Wangai." Kiel : Universitätsbibliothek Kiel, 2017. http://d-nb.info/1140054120/34.
Full text
17
Dillon, Rebecca. "Re-evaluation of north-temperate reservoir food web interactions and their assessment." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1594472755977476.
Full text
18
Gordon, Line. "Land Use, Freshwater Flows and Ecosystem Services in an Era of Global Change." Doctoral thesis, Stockholm : Univ, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-16.
Full text
19
Santos, Martha Raquel Pereira. "Bacterial community as a complementary tool to the water directive framework in ecological quality assessment of Caima river." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/21461.
Full textAbstract:
Mestrado em MicrobiologiaFreshwater ecosystems have been suffering severe degradation and loss of biodiversity, caused by human disturbances such as agriculture, industry, mining, urban development and climate changes. Therefore, the European Union reached an agreement and implemented the Water Framework Directive (WFD), with the main goal of reach a good ecological status in all water bodies. However, WFD is very complex, methodologies are time-consuming and costly. Thus, the main objective of this study is to develop a rapid and cost-effective approach, by studying the bacterial community composition by flow cytometry, as a complementary methodology to WFD. To achieve this, we study 3 sampling sites at Caima River along the seasons (winter, spring and summer), with different levels of environmental impacts (Nascente- river source- with little impact, Bustelo- downstream WWTP and Palhal- exposed to mine drainage), applying first the WFD criteria and then multivariate analysis for macroinvertebrate, periphyton and bacteria communities. Physico-chemical, metals and bacteria samples were collected from the water column and sediment river bottom, showing that in all the parameters (with some exceptions) and metals the concentrations were higher in sediments. Results showed that not always the macroinvertebrate and periphyton communities were sensitive to an increased nutrient input, resulting in an ecological status higher than expected. On the other hand, community structure analysis for macroinvertebrates and periphyton was very discriminatory, associating high levels of nutrients and metals with more tolerant organisms in impacted sites, and sensitive organisms with high levels of dissolved oxygen corresponding to pristine environments. Bacteria community analysis revealed a clear separation of LNA and HNA bacteria in sediment according to the different environmental stress, being possible to dissociate the majority of the impacted sites from the clean sites, being HNA a good indicator of contamination. These results revealed that bacteria community in sediments has more reliable data about the impacts that a freshwater ecosystem can suffer. The discriminating power of bacteria community analyzed by FCM provided good responses, although, further investigations are needed to confirm the feasibility of this new method, as a complementary tool in the water quality assessment.
Os sistemas aquáticos de água doce têm vindo a sofrer uma severa degradação e perda de biodiversidade, derivado de atividades humanas como a agricultura, indústria, atividades mineiras desenvolvimento urbano e alterações climáticas. Assim, a União Europeia implementou a Diretiva Quadro da Água (DQA), com o principal objetivo de atingir o bom estado ecológico em todas as massas de água. No entanto, a DQA revelou ser bastante complexa, com metodologias muito morosas e dispendiosas. Com este estudo, pretende-se desenvolver uma metodologia rápida e económica, estudando a composição da comunidade bacteriana por citometria de fluxo, como ferramenta complementar à DQA. Para a concretização deste trabalho, foram estudados 3 locais do rio Caima com diferentes tipos de impactos: a nascente – local de referência; Bustelo - a jusante de uma estação de tratamento de águas residuais e o Palhal - com escorrências provenientes de uma mina desativada, no inverno, primavera e verão aplicando a metodologia estabelecidas pela DQA usando os macroinvertebrados e perifiton como comunidades biológicas estudadas. Adicionalmente foi aplicada a análise multivariada aos dados recolhidos por citometria de fluxo à comunidade de bactérias da coluna de água e dos elutriados dos sedimentos e aos resultados das comunidades de macroinvertebrados e perifiton obtidos da DQA. No geral, os parâmetros físico-químicos, e as quantificações de metais mostraram valores mais elevados nos elutriados dos sedimentos do rio, do que na coluna de água mostrando a importância da análise desta matriz que não está contemplada na DQA. Resultados sensu DQA mostraram que nem sempre as comunidades de macroinvertebrados e perifiton foram concordantes na resposta aos diferentes tipos de impactos e que a qualidade ecológica dos locais avaliados foi melhor do que era expectável. Por outro lado, a análise multivariada das comunidades de macroinvertebrados e perifiton foi bastante discriminatória, associando elevados níveis de nutrientes e metais com organismos mais tolerantes, que se encontram em locais mais impactados, e organismos sensíveis com altos níveis de oxigénio dissolvido em locais mais pristinos. A análise da comunidade bacteriana revelou uma distinta separação entre bactérias LNA e HNA nos sedimentos, de acordo com os diferentes stresses ambientais, sendo HNA, nos sedimentos, um ótimo indicador de contaminação. Estes resultados revelam que a comunidade bacteriana oferece uma boa resolução de locais contaminados usando a citometria de fluxo como metodologia rápida de avaliação complementar à avaliação do estado ecológico sensu DQA sendo, no entanto, necessárias mais estudos aplicados a outras tipologias de rios e outros tipos de impactos para confirmar a validade desta nova metodologia.
20
Buzulencia, Hayley Catherine. "THE CHARACTERIZATION AND SURVEY OF INORGANIC SULFUR REDOX ASSOCIATED WITH WETLAND HYDROLOGICAL FLUCTUATIONS." Kent State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=kent1574288446961206.
Full text
21
Jackson, Breeanne Kathleen. "The role of wildfire in shaping the structure and function of California `Mediterranean’ stream-riparian ecosystems in Yosemite National Park." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1431014316.
Full text
22
Nolfi, Daniel C. "National Park Service Cave and Karst Resources Management Case Study: Great Smoky Mountains National Park." TopSCHOLAR®, 2011. http://digitalcommons.wku.edu/theses/1053.
Full textAbstract:
As discussed in the National Parks Service’s (NPS) Directors Orders/Natural Resources Management Reference Manual #77 and the 2006 NPS Management Policy Handbook, implementing a management plan specifically for cave and karst resources within a national park is paramount to afford these resources appropriate protection. With support from the Federal Cave Resources Protection Act and the National Park Service Organic Act of 1906, management actions protecting caves has begun to place significant importance outside the traditional cave environment onto a broader karst landscape. The need to understand and protect the karst environment and caves as a karst resource has taken a much larger role in the scientific literature and has increased interest in its federal management application. Proactive management through the use of holistic karst wide management plans and programs is shown to provide superior measures for resource protection when compared to the shortcomings associated with reactive cave focused management. The use of Great Smoky Mountains National Park (GRSM) as a case study supports the need to develop and implement a proactive cave and karst management plan specific to their resources. Management decisions with regards to cave and karst resources currently follow the park's general directives and Superintendent's Compendium. GRSM’s caves and karst areas represent unique resources, such as extensive vertical relief and rare biota, requiring special management in order to effectively protect them and to manage those who study and recreate within them. Characteristics such as these necessitate holistically addressing management of these resources.
23
Maseti, Pumza Penelope. "Biomonitoring in two contrasting catchments." Thesis, Rhodes University, 2006. http://hdl.handle.net/10962/d1006175.
Full textAbstract:
The introduction of instream biological monitoring to water resources management has been an increasing trend world-wide. This monitoring uses biological field assessments of instream biota such as macroinvertebrates, fish and riparian vegetation as an integrated and sensitive tool for diagnosing the condition of the ecosystems and assessing ecological impacts. Biomonitoring information has become an important component in the overall assessment of water resources and is used to drive and direct processes of decision-making and management of water resources. The River Health Programme (RHP) was initiated in South Africa to serve as a source of information regarding the ecological status of river systems, in order to support rational management of these natural resources. In this study, biomonitoring indices (SASS5 and FAII) were used to assess the present ecological status of two rivers located in contrasting catchments of the Eastern Cape. The first river is the Buffalo River located in an urban and industrialized catchment. The second river is the Inxu River draining a rural and afforested catchment. SASS5 was used successfully in both rivers and the results based on water quality and SASS5 indicated that most sites selected on the upper catchment of the Buffalo River have a fair water quality with most sites selected on the lower catchment having a poor water quality. The Inxu River sites (both upper and lower catchment) based on SASS5 and water quality results have a good to fair water quality. The majority of sites sampled on both rivers systems had very low FAII scores and fell within a critically modified water quality category. This result may be due to the fact that these rivers have low fish diversities (either low natural diversity or low diversity due to the presence of alien fish species), poor water quality or inadequate sampling methods. Observations from this study suggest that this index may not be suitable for rivers with low fish diversity. A fish index that is usable to all ecoregions of South Africa with minor adaptations to suit local conditions is still needed, as the present FAII index does not meet these requirements.
24
Fordham, Colin Justin. "A spatial and temporal analysis of the changes in alien macrophyte communities and a baseline assessment of the macroinvertebrates associated with Eurasian watermilfoil, Myriophyllum spicatum L. (Haloragaceae) in the Vaal River." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1005455.
Full textAbstract:
The majority of South Africa’s fresh water (lotic and lentic), is eutrophic and this has resulted in water hyacinth, Eichhornia crassipes (C.Mart.) Solms. (Pontederiaceae) becoming South Africa’s most damaging aquatic macrophyte. Recently however, concerns have also been voiced over the presence of highly invasive submerged macrophyte species, such as Eurasian water-milfoil, Myriophyllum spicatum L. (Haloragaceae) in the Vaal River. Interaction studies between floating and submerged macrophytes have shown that floating macrophyte dominance restricts light penetration into the water column shading out submerged macrophytes while submerged macrophyte dominance reduces nutrient availability in the water column limiting floating macrophyte growth. This cycle ensures that these species cannot coexist in the same habitat for extended periods of time. The aims of this thesis were to: 1. Investigate changes in the historical and current macrophyte dominance in the Vaal River 2. Determine whether these changes could be attributed to stochastic events, such as floods and herbicide control measures. 3. The physio-chemical conditions of the water column, and whether pressure from herbivory by macroinvertebrates had possibly influenced Eurasian water-milfoil’s ability to dominate. Spatial and temporal analysis of satellite imagery revealed that water hyacinth and submerged macrophyte species dominated different regions of the study area over different periods of time from 2006 to 2010. This was significantly correlated with nitrate concentrations of the water column. One of the lower Vaal River Water Management Areas (WMA) had changed from a water hyacinth dominated state in 2006 to an alternative submerged macrophyte dominated stable state in 2008. It was concluded that this change could be attributed to: a stochastic flooding event in 2006; perturbation from integrated control measures implemented against water hyacinth; and low nitrate concentrations of the WMA. The lack of any substantial macroinvertebrate herbivory pressure or control measures implemented against Eurasian water-milfoil, compared to similar surveys conducted in the U.S.A. and its native range in Eurasia was shown to contribute to its dominance. Future successful integrated control programmes, including biological control against Eurasian water-milfoil, could provide the perturbation required to restore the ecosystem. However, without the reduction in nitrate concentration levels, water hyacinth will remain the dominant stable state of the rest of the Vaal River.
25
Iranawati, Feni. "An assessment of the geographical scale of recurrent gene flow in wild populations of two species of Mekong River carps (Henicorhynchus spp.)." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/71217/1/Feni_Iranawati_Thesis.pdf.
Full textAbstract:
The Mekong is the most productive river fishery in the world, and such as, the Mekong River Basin (MRB) is very important to very large human populations across the region as a source of revenue (through fishing and marketing of aquatic resources products) and as the major source for local animal protein. Threats to biodiversity in the MRB, either to the fishery sector itself or to other sectors are a major concern, even though currently, fisheries across this region are still very productive. If not managed properly however, fish population declines will cause significant economic impact and affect livelihoods of local people and will have a major impact on food security and nutrition.
Biodiversity declines will undoubtedly affect food security, income and socio-economic status of people in the MRB that depend on aquatic resources. This is an indicator of unsustainable development and hence should be avoided. Genetic diversity (biodiversity) that can be measured using techniques based on DNA markers; refers to variation within and among populations within the same species or reproductive units. In a population, new genetic variation is generated by sexual recombination contributed by individuals with mutations in genes and chromosomes. Over time, populations of a species that are not reproducing together will diverge as differential impacts of selection and genetic drift change their genetic attributes. For mud carp (Henicorhynchus spp.), understanding the status of breeding units in the MRB will be important for their long term persistence, sustainability and for implementing effective management strategies.
Earlier analysis of stock structure in two economically important mud carp species (Henicorhynchus siamensis and H. lobatus) in the MRB completed with mtDNA markers identified a number of populations of both species where gene flow had apparently been interrupted or reduced but applying these data directly to management unit identification is potentially compromised because information was only available about female dispersal patterns. The current study aimed to address this problem and to fully assess the extent of current gene flow (nDNA) and reproductive exchange among selected wild populations of two species of carp (Henicorhynchus spp.) of high economic importance in the MRB using combined mtDNA and nDNA markers. In combination, the data can be used to define effective management units for each species.
In general, nDNA diversity for H. lobatus (with average allelic richness (A) 7.56 and average heterozygosity (Ho) 0.61) was very similar to that identified for H. siamensis (A = 6.81 and Ho = 0.75). Both mud carp species show significant but low FST estimates among populations as a result of lower genetic diversity among sampled populations compared with genetic diversity within populations that may potentially mask any 'real' population structure. Overall, population genetic structure patterns from mtDNA and nDNA in both Henicorhynchus species were largely congruent. Different population structures however, were identified for the two Henicorhynchus species across the same geographical area. Apparent co-similarity in morphology and co-distribution of these two relatively closely related species does not apparently imply parallel evolutionary histories. Differences in each species population structure likely reflect historical drainage rearrangement of the Mekong River. The data indicate that H. siamensis is likely to have occupied the Mekong system for much longer than has H. lobatus in the past. Two divergent stocks were identified for H. lobatus in the MRB below the Khone Falls while a single stock had been evident in the earlier mtDNA study. This suggests that the two Henicorhynchus species may possess different life history traits and that different patterns of gene flow has likely influenced modern genetic structure in these close congeners.
In combination, results of the earlier mtDNA and the current study have implications for effective management of both Henicorhynchus species across the MRB. Currently, both species are essentially treated as a single management unit in this region. This strategy may be appropriate for H. lobatus as a single stock was evident in the main stream of the MRB, but may not be appropriate for H. siamensis as more than a single stock was identified across the same range for this species. Management strategies should consider this difference to conserve overall biodiversity (local discrete populations) and this will include maintaining natural habitat and migration pathways, provision of fish sanctuaries (refuges) and may also require close monitoring of any stock declines, a signal that may require effective recovery strategies.
26
Tengö, Maria. "Management Practices for Dealing with Uncertainty and Change : Social-Ecological Systems in Tanzania and Madagascar." Doctoral thesis, Stockholms universitet, Institutionen för systemekologi, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-309.
Full textAbstract:
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.
27
Alaibakhsh, Masoomeh. "Digital change detection and separation of anthropogenic and natural impacts on ecohydrological conditions in the Pilbara region, WA." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2017. https://ro.ecu.edu.au/theses/1951.
Full textAbstract:
A deficiency in crucial digital data, such as vegetation cover, in remote regions is a challenging issue for sustainable water management and planning, especially for areas undergoing rapid development, such as mining in the Pilbara, Western Australia. This is particularly relevant to Inflow and Groundwater Dependent Vegetation (IGDVs) (riparian vegetation and groundwater dependent vegetation) which provide important ecological services and, as such, require regional protection. However, such invaluable assets experience changes over time due to either human activities such as land development or natural phenomena such as climate change or fire events.
The main objectives of this research was to 1) advance an approach to delineate inflow dependent ecosystems at a local scale; 2) adopt it to map the assets at regional scale using remotely sensed data (Landsat 5 TM imagery due to its appropriate temporal and spatial resolution for historical studies, 1986-2011), ground-truth data and available information such as reports, digital layer and climate data; 3) develop a method for identification and quantitative assessment of IGDVs changes and attribution of the changes to particular impacts or stressors, and 4) apply the developed change detection method to investigate and evaluate impacts of an adopted water resource management options on inflow dependent assets in the Pilbara.
Outcomes of the research exposed that the proposed delineation method allowed production of accurate inflow dependent ecosystems maps for the Pilbara bioregion. The change detection method was also effective in detecting various spatial and temporal scales of changes and separating anthropogenic and natural impacts. It was further discovered that climate has had significant impacts on the assets of the area.
The finding and information produced from this research is capable to aid government, industry and communities to consider the environmental, social, cultural and economic aspects of the sustainable use, development and management of land and water resources in arid and semiarid Pilbara, WA and areas with similar ecohydrological conditions. Four papers were prepared from the research, two are published and two are under review.
28
Simaika, John P. "Conservation biogeography of South African dragonflies (Odonata)." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1711.
Full text
29
Wilbur, Cricket C. "A History of Place: Using Phytolith Analysis to Discern Holocene Vegetation Change on Sanak Island, Western Gulf of Alaska." Antioch University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1395927847.
Full text
30
Pittock, Jamie. "Integrating management of freshwater ecosystems and climate change." Phd thesis, 2011. http://hdl.handle.net/1885/150245.
Full textAbstract:
Sustaining freshwater ecosystems and responding to climate change are two of the greatest challenges facing humanity. Climate change and water are intimately linked: changes in climate affect hydrology, and societal responses to climate change (e.g. through mitigation and adaptation measures) affect water use. Thus, the management of climate change and water needs to be integrated to maximise benefits for people and nature conservation. This research asked 'What institutions and other tools can governments and societies most successfully apply, to integrate management of freshwater ecosystems?' To answer this question, the research examined management of freshwater ecosystems and climate change through different lenses, from the global to the local scales. At the international scale, the issue was explored from a 'new institutionalism' perspective, by systematically examining the key multilateral environment agreements adopted to manage climate change, biodiversity and water - the United Nations Framework Convention on Climate Change (UNFCCC), the Convention on Biological Diversity (CBD) and the Ramsar Convention on Wetlands. Documentary records from these regimes were examined for evidence of conflicts and positive synergies in policy integration, and the deployment of mechanisms for such integration. Each of these conventions requires national governments to integrate measures to achieve the objectives of the conventions into all appropriate sectoral institutions. This research showed that horizontal (at the same scale) and vertical (from global to local scale) integration mechanisms are missing, or poorly used. As a result, international climate change policies are having perverse impacts on freshwater ecosystems, and opportunities are being missed for positive, synergistic implementation of the three conventions. The papers presented here recommend responses that can improve such integration. At a national level, the research assessed national priorities and the state of integration of climate, energy, water and biodiversity policies from Australia, Brazil, China, the European Union, India, Mexico, South Africa, Tanzania and the United Kingdom. The sectoral silos identified were similar to those at the international scale. A framework for policy integration was used to assess legislation, coordination, leadership, and mechanisms for consultation and review. Numerous examples of negative impacts of climate change mitigation policies on freshwater ecosystems were identified, and few positive, synergistic measures were found. Developing countries had more holistic policies linking climate change adaptation and mitigation, whereas developed jurisdictions had conflated climate and energy policies. Little evidence was found of national governments either deploying tools that would aid conservation of freshwater ecosystems, or adopting measures to better enable subnational institutions to adapt to climate change. The research presented here recommends more systematic adoption of the better policy integration practices identified at the national scale. A number of long-standing measures for management of freshwater ecosystems were examined to see whether they continue to provide benefits for conservation as hydrology changes with the climate. The tools assessed were freshwater protected areas, environmental water allocations and periodic relicensing of water infrastructure. It was found that these measures have considerable benefits for freshwater conservation under climate change, can be applied now, and can be even more effective if modified to better account for the impacts of climate change. Empirical research undertaken at the local to basin scale assessed lessons from autonomous adaptation in river-basin management for more effective climate change adaptation. Six programs were assessed, from Brazil, China, India, Mexico, Tanzania and four eastern European countries along the lower Danube River. Eight main lessons were identified for more effective adaptation: providing multiple benefits; communicating opportunities for adaptation; promoting local ownership; providing immediate benefits; undertaking adaptive management; linking local, national and global institutions; providing consistent funding for adaptation; and seizing policy reform windows. The research found that national governments need to focus on facilitating adaptation through existing local institutions, especially through enabling laws, information and financing mechanisms. This work was supplemented with research on climate change adaption responses by governments in Australia's Murray-Darling basin. A number of responses to drought were identified as maladaption (both physically and as opportunity costs), because they were not sufficiently far-reaching for effective adaptation to climate change. At each scale, a framework of appropriate measures in legislation, leadership, horizontal integration, vertical integration, review and advisory mechanisms proved to be a robust framework for better management of freshwater ecosystems and climate change. While there are good-practice examples at all geopolitical scales, they are not often applied. Thus, at each scale, there are many opportunity for better integration and more positive, synergistic outcomes. It is clear that the large epistemological community and 'high politics' that has developed around climate change has a downside; that is, a limited engagement with other sectors. Hence, freshwater ecosystems and resources may be adversely affected by climate change both directly, as hydrology changes, and indirectly, through perverse impacts of mitigation and adaptation policies. Further research is needed to examine why international and national institutions have not better integrated their policies for management of freshwater ecosystems and climate change, to implement more sustainable solutions.
31
Nogueira, Joana Filipa Garrido. "Freshwater biodiversity assessment in areas with and without protection." Master's thesis, 2019. http://hdl.handle.net/1822/65330.
Full textAbstract:
Dissertação de mestrado em EcologyFreshwater ecosystems are essential to human well-being and are considered areas of high biodiversity. However, this biodiversity has been suffering severe declines due to the expansion of human activities. Protected areas are essential for biodiversity conservation and have proven to be successful in stopping species extirpation, when managed properly. Unfortunately, they are usually focused on terrestrial biodiversity, leaving many times freshwater ecosystems aside. The main goal of this study was to determine the influence that the Montesinho Natural Park (MNP), mainly designed to protect terrestrial biodiversity, has on freshwater biodiversity present in Mente, Rabaçal, Tuela and Sabor Rivers. Therefore, we sampled two aquatic faunal groups: fishes and invertebrates (bivalves and other macroinvertebrates) inside, in the periphery and outside the MNP. Biodiversity (richness, abundance, Shannon-Wiener diversity and Pielou’s evenness) and water quality (IBMWP, IASPT and %EPT) indices were calculated. It would be expected that results indicated better abiotic and biological conditions inside the park. However, this was not the case, with results showing that the protected area does not affect positively neither water quality nor the two faunal groups monitored. The macroinvertebrate communities and Margaritifera margaritifera abundance were not influenced by the protected area and only M. margaritifera length was significantly lower inside the MNP. For the fish communities, richness and abundance were significantly higher outside the protected area. Given these results, we conclude that MNP does not guarantee protection for the aquatic biodiversity and its ecosystems. This work highlights the view that protected areas need to be designed and managed for aquatic biodiversity if they intend to be successful in their conservation. Control of non-native species, reduction of point source pollution, regulation of fisheries and improvement of rivers connectivity are some of the most important actions that need to be taken by governmental, local population and stakeholders in order to achieve a proper protection of freshwater ecosystems and prevent the extirpation of species with conservation importance.
Os ecossistemas de água-doce são essenciais para o bem-estar humano, sendo consideradas áreas com grande biodiversidade. No entanto, esta tem sofrido uma diminuição enorme devido à expansão das atividades humanas. As áreas protegidas são essenciais para a conservação da biodiversidade e já provaram ser bem-sucedidas em travar a extirpação de espécies quando são bem geridas. Infelizmente, são maioritariamente focadas na biodiversidade terrestre, ignorando muitas vezes os ecossistemas de água-doce. O principal objetivo deste trabalho foi determinar a influência do Parque Natural de Montesinho (PNM), que foi projetado para proteger a fauna terrestre, na biodiversidade de água-doce presente nos Rios Mente, Rabaçal, Tuela e Sabor. Assim sendo, foram amostrados dois grupos faunísticos: peixes e invertebrados (bivalves e outros macroinvertebrados) dentro, na periferia e fora do PNM. Com estes dados foram calculados índices de diversidade (riqueza, abundância, diversidade de Shannon-Wiener e equitabilidade de Pielou) e índices de qualidade de água (IBMWP, IASPT e %EPT). Seria expectável que os resultados indicassem uma melhor condição abiótica e biológica dentro do parque. Contudo, este não foi o caso pois os resultados mostraram que a área protegida não afeta positivamente nem a qualidade de água nem nenhum dos dois grupos faunísticos monitorizado. As comunidades de macroinvertebrados e a abundância de Margaritifera margaritifera não foram influenciadas pela área protegida e apenas os comprimentos de M. margaritifera foram significativamente menores dentro do PNM. No que diz respeito às comunidades de peixes, a riqueza e a abundância foram significativamente maiores fora da área protegida. Assim sendo, concluímos que o PNM não garante a proteção de espécies aquáticas e dos seus ecossistemas. Este trabalho reforça a visão de que as áreas protegidas têm que ser desenhadas e geridas tendo também em conta a diversidade aquática se tencionam ser eficazes na sua proteção. O controlo de espécies nãonativas, a redução de fontes localizadas de poluição, a regulação das pescas e a melhoria da conectividade dos rios são algumas das medidas mais importantes a tomar pelo governo, pela população local e por outras partes interessadas de modo a alcançar uma proteção adequada dos ecossistemas de água-doce e impedir a extirpação de espécies com importância de conservação.
32
Mattocks, Steven R. "Ecological Consequences of Lost Anadromous Forage Fish in Freshwater Ecosystems." 2016. https://scholarworks.umass.edu/masters_theses_2/433.
Full textAbstract:
Beginning in the early 1600s, dam construction in New England obstructed anadromous fish access to spawning grounds during migration. As a result, anadromous forage fish populations have declined, which has impacted freshwater, marine, and terrestrial ecosystems. To determine the impacts of dams on anadromous forage fish and freshwater ecosystems, I used historical and current data to estimate population changes in alewives (Alosa pseudoharengus) from 1600-1900. A significant reduction in spawning habitat occurred in New England as a result of 1,642 dams constructed between 1600 and 1900, resulting in 14.8% and 16.6% lake and stream habitat remaining by 1900, respectively. In eight New England watersheds, this translates to an estimated cumulative annual loss of 30 B juvenile alewives available as freshwater forage and 538 M year 1, 2 and 3 alewives available as marine forage. The cumulative annual lost number of adult return spawners was conservatively 17 M fish, or 3,642 metric tons. Lost marine-derived nutrients from adult return spawners were 11 T phosphorus, 64 T nitrogen, and 410 T carbon. A comparison of predator fish growth and condition in alewife and non-alewife lakes showed that white perch (Morone Americana) and yellow perch (Perca flavescens) have higher condition in early summer in lakes with alewives. Predator growth rates (length-at-age) were significantly higher in early life stages (ages 1 and 2) when alewives were present, but significantly lower in late life stages (ages 3 and older). Results indicate a greater maximum length obtained by mature fish when alewives are absent, and an earlier age and length at maturity when alewives are present. These results indicate significant ecosystem impacts of lost anadromous forage fish, with bottom-up trophic effects across multiple time scales and biological processes. An ecosystem-based management approach should be used by inland and marine aquatic managers, and ecosystem connectivity and trophic interactions should be considered when managing migratory fish and prioritizing restoration goals.
33
MCCLEARY, KATHRYN. "A comparative paleolimnological assessment of the influences of early Arctic population groups on freshwater ecosystems from southern Baffin Island, Nunavut." Thesis, 2011. http://hdl.handle.net/1974/6827.
Full textAbstract:
Recent paleolimnological research in the eastern Canadian high Arctic on the ecological impact of the Thule c.1000-1500 AD has documented the influence of prehistoric anthropogenic activities. Six lake and pond sites (three pairs) on the south-western coast of Baffin Island, Nunavut, were used to compare impacted and non-impacted sites in the southern-most region of Thule occupation, as well as to compare Thule occupation sites with sites occupied by another early Arctic population group, the Dorset. Tanfield 1 and Tanfield 2 (impacted and control, respectively) are adjacent to several multiple-occupation Dorset sites on Cape Tanfield; Juet 1 and 2 (impacted and control, respectively) are adjacent to a short-term occupation Dorset site on Juet Island; McKellar 1 is adjacent to a multiple-occupation Thule site near McKellar Bay. A nearby site (McKellar 2) was also studied, but it was clearly an anomalous, eutrophic site, rather than a control for McKellar 1. Diatom assemblages and sedimentary 15N profiles were analyzed in sediment cores from all study sites. Selected paired sediment intervals were AMS radiocarbon dated using both humic acids and terrestrial macrofossils in an attempt to establish basal dates for each core. Significant differences between several of the paired AMS radiocarbon dates serve as a cautionary note for dating Arctic sediments using either humic acids or terrestrial macrofossils. Paleolimnological analyses revealed that at both multiple-occupation sites (Tanfield 1 and McKellar 1), the activities of the Dorset and the Thule influenced lake ecology, while at the short-term occupation site (Juet 1), the Dorset occupation was not sufficiently large to have a discernible impact. McKellar 1 showed a greater impact compared to Tanfield 1, consistent with the intense marine mammal hunting by Thule at the former, compared to the moderate marine mammal hunting by Dorset at Tanfield 1. The origin of marine-derived nutrients at McKellar 2 could not be ascertained with certainty. The influence of early Arctic population groups remains obvious in present-day nutrient- and production-related water chemistry variables. This research points to the value of collaborations between paleolimnologists and archaeologists and may provide insight into the future implications of current anthropogenic activities in the Arctic.Thesis (Master, Biology) -- Queen's University, 2011-10-04 15:52:18.29
34
"Regional scale risk assessment methodology using the relative risk model as a management tool for aquatic ecosystems in South Africa." Thesis, 2012. http://hdl.handle.net/10210/8096.
Full textAbstract:
Ph.D. (Zoology)Due to the excessive utilisation of the ecological services of surface aquatic ecosystems in South Africa, the integrity state of these systems continues to decline resulting in the loss of key ecosystem services. This trend suggests that the national requirements to maintain a sustainable balance between the use and protection of these systems are not being met. In an attempt to address this status quo, all stakeholders of these systems need to become more closely engaged in the social and institutional decision making processes to manage these systems. Management plans need to be integrated and take a wide range of conservation and use objectives for specific ecosystems into account. Furthermore, approaches need to allow for the assessment of multiple stressors that have synergistic effects, while the unique characteristics of the ecosystem taken into consideration. Risk assessments entail assigning magnitudes and probabilities to hazards or anthropogenic activities or natural catastrophes that have adverse effects m ecosystems. In these assessments the existence of a hazard and the related uncertainty of its effects results in the formulation of risk. An Ecological Risk Assessment is a structured approach that describes, explains and organises scientific facts, laws and relationships, thereby providing a sound basis to develop sufficient protection measures for the environment, which facilitates the development of utilisation strategies for the environment. A Regional Scale Risk assessment using the Relative Risk Model (RRM) is a form of Ecological Risk Assessment that is carried out on a spatial scale where considerations of multiple sources of multiple stressors affecting multiple endpoints are allowed. The use of the RRM also allows for the characteristics of the landscape that may affect the risk estimate to be considered. This study is based on a research hypothesis that the RRM is a suitable water resources management tool that can address the risk assessment of multiple stressors in South African freshwater environments. To test this hypothesis this study aims to contextualise the RRM methodology within the current water resources management practices in South Africa and demonstrate the applicability of RRM within the South African water resources management framework. The applicability of the RRM will be tested using two case study regions. The case studies are the Elands River and its associated ecosystems in the upper Crocodile River catchment in Mpumalanga and the entire catchment of the Umvoti River in KwaZulu-Natal
35
Horrigan, Nelli. "Neural network based decision support framework for the assessment and management of freshwater stream habitats." 2005. http://hdl.handle.net/2440/37736.
Full textAbstract:
Modelling of stream macroinvertebrate communities has been widely accepted as an interesting and powerful tool to support water quality assessment and management. Stream Decision Support Framework (SDSF) offers an alternative approach to the current statistical models as Australian River Assessment Scheme (AusRivAs) for the derivation of scientific basis to support management applications regarding fresh water systems. Implementation of Artificial Neural Networks (ANNs) offers a possibility to overcome constraints of the statistical methods in dealing with high nonlinearity of stream data. This thesis includes several case studies illustrating application of Self Organising Map (SOM) and Multilayer Perceptron (MLP) neural networks to various tasks involving analysis, assessment and prediction of stream macroinvertebrates in three Australian states. The data for this study have been provided by the Queensland Department of Natural Resources (NR&M), EPA Victoria and the Department of Land and Water Conservation, New South Wales (NSW). SDSF approach utilises predictive models for both 'referential' and 'dirty-water' approaches. Applicability and high accuracy of ANN models for the purpose of prediction both occurrence of individual taxa and taxonomic richness of stream macroinvertebrates have been demonstrated using data from Victoria and NSW. A comprehensive analysis of salinity sensitivity of stream macroinvertebrate has been demonstrated using both types of ANNs plus statistical methods, and pressure specific Salinity Index was suggested as a measurement of changes within macroinvertebrate communities in response to the secondary salinisation. Scenario analysis of the combined effect of increasing salinity and nutrient load demonstrated predictability and ecological meaningfulness of the Salinity Index. Application of SOM has been demonstrated using the data from Queensland and Victoria in order to analyse natural variability of macroinvertebrate communities between reference sites. SOM component planes provided a valuable insight into the relationships between abiotic variables (as water quality and geoclimatic factors) and distribution of taxa and trophic structure of macroinvertebrate communities. Potential of SOM as data exploration tool has been also demonstrated for the analysis of the output of scenario simulation in order to understand the difference in response to salinisation in different sites. Flexibility and potential of SDSF have been illustrated by using the combination of SOM and MLP, and combination of ANNs with statistical methods. Application of both SOM and Canonical Correspondence Analysis allowed the extraction of additional information and provided convenient visualisation of the relationships between water quality factors and the structure of macroinvertebrate communities. In general, SDSF provides convenient, flexible and accurate approach for the analysis, assessment and prediction of stream biota. In addition to the freedom from the limitations inherent to the traditional statistical methods it allows many more options than currently used modelling frameworks, namely: highly accurate predictions using both 'referential' and 'dirty-water' approaches, sensitivity analysis, scenario analysis and pattern exploration using SOM.Thesis (Ph.D.)--School of Earth & Environmental Sciences, 2005.
36
Maseti, Pumza Penelope. "Biomonitoring in two contrasting catchments /." 2005. http://eprints.ru.ac.za/243/.
Full text
37
Mutch, Paul D. "Assessment of small scale tallgrass prairie restoration in an urban environment." 2007. http://hdl.handle.net/1993/2944.
Full textAbstract:
Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence.February 2008
38
(8098112), Ben L. Gottesman. "Using Soundscapes to Measure Biodiversity, Habitat Condition, and Environmental Change in Aquatic Ecosystems." Thesis, 2019.
Find full textAbstract:
Biodiversity loss is the silent crisis of the 21st century. Human activities are drastically altering the diversity of life on Earth, yet the extent of this transformation is shrouded by our limited information on biodiversity and how it is changing. Emerging technologies may be suited to fill this information gap, and as a result increase our capacity to measure and manage natural systems. Acoustic monitoring is a remote sensing technique that is rapidly reshaping the temporal and spatial scales with which we can assess animal biodiversity. Through recording and analyzing soundscapes—the collection of sounds occurring at a given place and time—we can assess biodiversity, habitat condition, and environmental change. However, the relationships between soundscapes and these three ecological dimensions are still in the early phases of categorization, especially in aquatic systems.
This dissertation investigates how soundscapes can be used to measure biodiversity, habitat condition, and environmental change in aquatic habitats. It addresses several knowledge gaps: First, I develop a framework for classifying unknown sounds within a soundscape, which I use to measure the acoustic diversity and dynamics within a tropical freshwater wetland. Second, I demonstrate that soundscapes can reflect the resilience of animal communities following disturbance events. Altered soundscapes revealed that Hurricane Maria, which swept through Puerto Rico in September 2017, impacted dry forest animal communities more than adjacent coral reef communities. Third, in kelp forest habitats off the coast of California, USA, I showed that soundscape variables correlated with ecological variables associated with regime shift in kelp forests, including urchin density, kelp cover, and fish diversity. Overall, this dissertation demonstrates that soundscape recording and analysis is a promising way to assess the ecological conditions of aquatic systems.
39
Dewson, Zoë Spence. "Small stream ecosystems and irrigation : an ecological assessment of water abstraction impacts : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Ecology at Massey University, Palmerston North, New Zealand." 2007. http://hdl.handle.net/10179/1575.
Full textAbstract:
Content removed due to copy right restriction: Dewson, Z.S., Death, R.G. & James, A.B.W. (2003) The effects of water abstractions on invertebrate communities in four small North Island streams. New Zealand natural Sciences 28, 51-65.Small streams are often used for small-scale water abstractions, but the effects of these water abstractions on the instream environment, invertebrate communities and ecosystem functioning of small permanent streams is poorly understood. This research extends current knowledge by surveying existing water abstractions and completing flow manipulation experiments in the field. Reduced discharge often decreases water velocity, water depth, and wetted channel width and can increase sedimentation, modify the thermal regime and alter water chemistry. In a survey of sites upstream and downstream of existing water abstractions, I found that downstream sites had higher densities of invertebrates, but fewer taxa sensitive to low water quality compared with upstream sites. There were greater differences in physicochemical characteristics such as velocity and conductivity and in invertebrate communities between upstream and downstream sites on streams where a larger proportion of total discharge was abstracted. Using before-after, control-impact (BACI) designed experiments, weirs and diversions were created to experimentally decrease discharge by over 85% in each ot three small streams, ranging from pristine to low water quality. The response of invertebrates to short-term (one-month) discharge reduction was to accumulate in the decreased available area, increasing local invertebrate density. After a year of reduced flow, the density of invertebrates and percentage of mayflies, stoneflies and caddisflies decreased at the pristine site, whereas only taxonomic richness decreased at the mildly polluted stream. Reduced discharge had no affect on the invertebrate community at the stream with the lowest water quality. Reduced discharge had little influence on leaf decomposition rates, but distances travelled by released coarse particulate organic matter (CPOM) increased with increasing discharge. The effects of reduced discharge on primary production were not consistent between streams. Overall, the severity (magnitude/duration) of flow reduction appeared to influence invertebrate responses to water abstraction although the outcomes of water abstraction were dependent on the invertebrate assemblage present in each stream.
40
Denault, Catherine. "Assessment of the likely impact of climate change on infrastructure and natural ecosystems of a small watershed in British Columbia : implications for hydraulic infrastructure design and stormwater management." Thesis, 2001. http://hdl.handle.net/2429/12024.
Full textAbstract:
The stationarity of rainfall statistical parameters is a fundamental assumption in hydraulic
infrastructure design. Given the increase in rainfall intensity associated with climate change,
this assumption might no longer prove valid. This study examines the possible impacts of
climate change on the urban infrastructure and natural ecosystems of a small watershed in
British Columbia. The methodology was developed with the purpose of providing simple
methods to evaluate drainage system vulnerability to increases in rainfall intensity, and to
envisage the potential economical and environmental impacts of climate change.
Non-stationarities in rainfall records are first analyzed with linear regression analysis, and the
detected trends are extrapolated to build future rainfall scenarios. The Storm Water
Management Model (SWMM) is then used to analyze the effects of increased rainfall
intensity on the Mission/Wagg Creek system. Anticipated changes in land use and the
projected changes in rainfall intensity are included in the simulations to obtain probable
future runoff conditions. The total length of undersized stormwater sewers, combined with
the total number of culverts found to be surcharging during the simulations, attests to the
vulnerability of the infrastructure network. An innovative method is proposed to investigate
the environmental impacts of climate change. Using SWMM, climate change equivalent
levels of imperviousness are determined. These levels represent the Total Impervious Areas
(TIAs) for which the runoff values are equal to the runoff values obtained under climate
change conditions. This method allows considering the well-researched impacts of
urbanization as likely impacts of climate change.
In terms of impacts on the infrastructure, the results of this study indicate that climate change
would not create severe impacts in the Mission/Wagg Creek system. The infrastructure in
place, with the exception of a few trunk sewers and culverts, has the adequate capacity to
handle the runoff generated by the future larger storms. The equivalent levels of
imperviousness, however, suggest that the impacts on the natural ecosystems of the creeks
could be far more damaging.
41
Hagström, Erika. "Utveckling av metod för att synliggöra och värdera ekosystemtjänster i öppen dagvattenhantering." Thesis, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-302162.
Full textAbstract:
Nature provides various services to society that humans are completely dependent on for their survival. These services are called ecosystem services, and can be, for example, clean air, clean water and pollination of crops. To live close to nature and green areas is also important for our well being. Although we are often aware of the values that nature creates and its importance, green areas are often replaced with buildings and roads as the big cities grow and densify. The ongoing densification of cities, combined with the projected climate changes will result in that the capacity of storm water pipes is likely to be insufficient during major rainstorms which can create big problems with, for example, flooding. The increasing challenges of storm water management resulted in that open storm water solutions began to be used as supplement to the storm water pipes. Open water solutions are designed to take care of water in a way that mimics nature's way of taking care of rainfall. These open water systems are a form of urban ecosystems and, in addition to dampen the water flows, can provide a range of other ecosystem services. The aim of this thesis was to create a method for integrating and valuing ecosystem services in the design of open storm water management and thus make the values from ecosystem services visible. The thesis was limited to investigating seven different open storm water solutions: green roofs, infiltration of lawns, temporary damming on specially constructed flood areas, percolation trenches, natural streams, ponds and wetlands. In addition to the ability to manage and control large water flows, 11 ecosystem services were identified that can be obtained from the open storm water solutions: drinking water, non-potable water, natural water purification, carbon sequestration and storage, local climate control and air purification, noise reduction, pollination, habitat and biodiversity, activity based cultural values, aesthetic values and resource for research and education. The values of the ecosystem services were determined in a semi-quantitative survey in which 16 people responded to questions examining to what extent they consider that ecosystem services can be obtained in the various storm water solutions. The values of the ecosystem services also depend largely on the site's potential and how the solutions are designed. Factors that can affect the value of the ecosystem services with respect to these aspects were investigated in a literature study and in the questionnaire study. The results of the literature study and questionnaire study formed the basis for the non-site adapted assessment tool that was developed as the last step in the thesis. The tool was designed in Excel and consists of three steps. Step 1 aims to weight the ecosystem services by the sites’ potential, step 2 involves the actual valuation and possible adaption to alternative design, and in step 3 a factor is calculated as a measure of the values obtained from ecosystem services created from open storm water solutions in relation to the total area. The aim is that the assessment tool should be used as a complement to an investigation about which storm water treatment solution that is most suitable in a project.Naturområden och grönytor levererar olika tjänster som människan är helt beroende av för sin överlevnad. Dessa tjänster kallas ekosystemtjänster och är exempelvis ren luft, rent vatten och pollinering av grödor. Närhet till naturen och grönområden har också stor betydelse för människans välbefinnande, till exempel genom att ha en stressdämpande effekt. Trots att vi är medvetna om värdena som naturen skapar, byggs grönytor i städer bort i takt med att de växer och förtätas. Täta städer innebär stora arealer hårdgjorda ytor vilket också resulterar i större volymer dagvatten då nederbörden inte kan infiltrera ner i marker och istället rinner av på ytan. Ledningarnas kapacitet riskerar att överskridas vid stora skyfall vilket kan orsaka stora problem med översvämningar. Problemet kommer dessutom förvärras i framtiden med de väntade klimatförändringarna. Ökande utmaningar med dagvattenhanteringen har resulterat i att öppna dagvattenlösningar började användas som komplement till ledningar under mark. Öppna dagvattenlösningar innebär att vattnet tas omhand på ett sätt som efterliknar naturens sätt att ta hand om nederbörd, och är en form av urbana ekosystem som, utöver att dämpa vattenflöden, kan tillhandahålla en rad andra ekosystemtjänster. Syftet med detta examensarbete var att skapa en metod för att integrera och värdera ekosystemtjänster i utformningen av öppen dagvattenhantering och därmed synliggöra ekosystemtjänsternas värden. Examensarbetet avgränsades till att utreda sju olika öppna dagvattenlösningar: gröna tak, infiltration på gräsytor, tillfällig uppdämning på översvämningsytor, svackdiken, naturliga diken och bäckar, dammar samt våtmarker. 12 ekosystemtjänster identifierades kunna erhållas från de öppna dagvattenlösningarna. Dessa var dricksvattenresurs, icke drickbart vatten, vattenrening, kolbindning och lagring, klimatreglering och luftrening, bullerreducering, flödesreglering, pollinering, livsmiljöer och biologisk mångfald, aktivitetsbaserade kulturella värden, estetiska värden samt resurs för forskning och utbildning. Ekosystemtjänsternas värden hos de olika dagvattenlösningarna bestämdes i en semikvantitativ enkätstudie där 16 personer fick värdera dagvattenlösningarnas kapacitet att bidra till de olika ekosystemtjänsterna. Värdena beror också till stor del på platsens förutsättningar och hur de utformas. Vilka faktorer som kan påverka värdet av ekosystemtjänsterna med avseende på dessa aspekter utreddes i en kvalitativ litteraturstudie. Resultatet från litteraturstudien samt enkätstudien utgjorde grunden för det icke platsanpassade värderingsverktyget som togs fram som det sista steget i examensarbetet. Verktyget utformades i Excel och består av tre steg där steg 1 syftar till att vikta ekosystemtjänsternas värden efter platsens förutsättningar, i steg 2 sker själva värderingen samt en eventuell anpassning till alternativ utformning och i steg 3 beräknas en faktor fram som är ett mått på ekosystemtjänsternas värden som fås från öppna dagvattenlösningar i förhållande till den totala arean. Syftet är att värderingsverktyget ska användas som ett komplement till en utredning om vilken dagvattenhantering som är lämpligast i ett projekt.
42
Oyeleke, Babawale Sowemimo. "Assessment of productivity and supply chain of aquaculture projects in Gauteng Province for sustainable operation." Diss., 2017. http://hdl.handle.net/10500/23118.
Full textAbstract:
The main aim of the study is to assess the productivity and supply chain of aquaculture projects in Gauteng Province, South Africa. The research adopted the use of quantitative method; and collected data and information from the five regions that make up the province. Both primary and secondary data were collected. The study used correlation analyses to determine the perfect fit or negative fit of some variables to supply chain as well as the consumers‟ reactions to the questionnaires. Gross margin analysis as well as gross profit margin ratio was used to determine the profitability of aquaculture production in the province.
Findings of the study revealed underutilization of production capacities of the established fish farms. The fish farmers in the study are currently using 36% of the capacities of the established aquaculture projects in the study area. The profit margin was in excess of 40% in all the projects surveyed. The study further revealed lack of proper, effective and efficient supply chain for aquaculture projects which adversely affect aquaculture growth and sustainability in Gauteng ProvinceAgriculture, Animal Health and Human Ecology
M. Sc. (Agriculture)
43
Ospan, Arman K. "A cumulative effect assessment using scenario analysis methodology to assess future Cowichan River Chinook and Coho salmon survival." Thesis, 2021. http://hdl.handle.net/1828/12939.
Full textAbstract:
This dissertation describes a proposed methodology for Cumulative Effects Assessment (CEA) with the purpose of improving the process by making it both more substantive and quantitative. The general principles of the approach include the following: use of effect-based analyses where selected Valued Component (VC) sensitivities are identified first and then effect pathways are determined building bottom-up linkages from VC sensitivities to potential stressors or combinations of stressors to effect drivers and forces behind the drivers. Models were developed based on statistical or historic trend analysis or literature review that predicted the responses of the VCs to changes in effect drivers. Further, scenarios of divergent futures were created that involved different developments of each effect driver or force, and finally the models were applied to each scenario to project the state of the studied VCs. A practical implementation was conducted to demonstrate the use of the proposed methods on future population trends of two anadromous salmon species from the Cowichan River, British Columbia, Chinook and Coho. The assessment was conducted for both early freshwater and marine phases of their life. For the freshwater phase, the assessment focused on two main factors affecting salmon survival, streamflow and stream temperature and established two main drivers affecting these stressors, land use and climate change, and two main forces behind these drivers, Local and Global human development driven change, respectively. Effects of stream temperature and streamflow on salmon freshwater survival were simulated using two models; one was based on Chinook freshwater survival correlations with stream temperature and was developed only for Chinook, and the other was based on literature-derived temperature and streamflow thresholds and was developed for both species. Connections between the stressors (stream temperature and streamflow) and drivers (land use and climate change) were established through a hydrologic model and stream temperature regression model. For the marine environment, models were created using Pearson correlation and stepwise regression analysis examining links between survival of Cowichan River Chinook and Strait of Georgia hatchery-raised and wild Coho and various environmental variables of the nearshore zone of Strait of Georgia and Juan de Fuca Strait. The models were applied to project future salmon survival under four future scenarios for 2050 that were created by combining two opposite scenarios of land use in the watershed, forest conservation and development, and two climate change scenarios, extreme and moderate. Scenario projections showed a decrease in overall (combined early freshwater marine) survival by 2050 for all three studied salmon populations. None of them are likely to survive in scenarios with extreme climate change, while scenarios with moderate climate change showed positive survival rates although lower than present-day baseline levels. Analysis also showed that land use management within the Cowichan River watershed can also affect freshwater survival of both Chinook and Coho and marine survival of Chinook through influence of river discharge on nearshore processes. However, our land-use management scenarios have considerably weaker effect than climate change on salmon survival. Therefore, we conclude that land use management alone is not sufficient to offset effects of climate change on salmon survival.Graduate