Tesis sobre el tema "Harbours and marinas"

Le développement côtier introduit des habitats artificiels qui impactent la biodiversité et le fonctionnement des écosystèmes. Les solutions d'ingénierie écologique, comme les habitats artificiels à poissons (HAP), peuvent réhabiliter des zones très modifiées, comme les ports, en offrant un abri aux poissons. Les HAP peuvent aussi fournir un substrat aux invertébrés et aux macroalgues, améliorant le fonctionnement de l'écosystème. Leurs effets pourraient aller au-delà des ports et modifier les échanges trophiques avec les habitats adjacents. Cette thèse étudie la biodiversité des invertébrés associés aux HAP et explore les échanges de biomasse entre les ports et les herbiers de Posidonia oceanica adjacents le long de la côte méditerranéenne française.Les objectifs sont : (1) évaluer comment la diversité et la composition des invertébrés benthiques varient avec le temps d'immersion des HAP, (2) comprendre comment les types d'HAP et le contexte environnemental modifient les assemblages benthiques, et (3) explorer les échanges de matière organique entre les ports et les herbiers adjacents. J'ai étudié les HAP Biohut® (ECOCEAN), composés d'une cage métallique remplie de coquilles d'huîtres, attachés aux quais ou sous les pontons dans les ports.Au chapitre 1, j'ai examiné le rôle du temps d'immersion des HAP sur la diversité et la composition des assemblages d'invertébrés dans 3 ports commerciaux. Des variations dans la composition des invertébrés ont été observées entre 6 et 18 mois d'immersion, avec une augmentation de l'abondance, de la richesse et de l'équitabilité au fil du temps. Au chapitre 2, j'ai étudié les variations géographiques et intra-portuaires de la composition et de la diversité des invertébrés. L'étude a révélé des différences dans la composition des taxons entre 2 régions caractérisées par des apports en nutriments différents et des corrélations entre la composition des assemblages et la chlorophylle-a, indicateur de la concentration en nutriments. Les assemblages d'invertébrés variaient aussi selon les zones où les HAP étaient installés, probablement à cause de différences d'accès à la lumière. Au chapitre 3, j'ai étudié la connectivité trophique entre les herbiers de P. oceanica et les ports adjacents sur 4 sites : 2 avec des ports équipés en HAP et 2 non équipés. Dans les sites non équipés, les valeurs δ15N de la matière organique particulaire à l'intérieur du port étaient les plus élevées, suggérant un enrichissement en nutriments d'origine humaine. Ces valeurs diminuaient dans les herbiers selon la distance, indiquant un effet de ces nutriments sur l'herbier proche de l'entrée du port. Les poissons (Diplodus spp.) pouvaient utiliser des ressources venant à la fois de l'herbier et du port de manière similaire sur les 4 sites. Les niches trophiques des poissons capturés dans le port équipé étaient légèrement plus grandes que celles des ports non équipés et se chevauchaient moins avec celles des poissons capturés à l'extérieur. Leurs fèces faisaient également partie de la matière organique sédimentaires des herbiers. Au chapitre 4, j'ai présenté des projets développés avec d'autres scientifiques sur la diversité fonctionnelle des espèces et les relations trophiques dans les HAP, des mesures bioacoustiques sur les AFH et une comparaison de la biodiversité entre les ports et les réserves marines à l'aide d'ADN environnemental.Mon travail a révélé des aspects susceptibles d'améliorer l'utilisation des HAP. La durée d'immersion, les conditions environnementales et les emplacements dans les ports doivent faire l'objet d'une attention particulière. Bien que je n'aie pas trouvé de différences claires dans les échanges entre habitats liés aux HAP, ces derniers semblent jouer un rôle en réduisant l'enrichissement en nutriments. L'importance des poissons dans les échanges entre habitats et le fait que les HAP favorisent leur survie suggèrent que ces HAP pourraient contribuer indirectement à la connectivité trophique<br>Coastal development modifies shorelines by introducing man-made habitats, which significantly impact coastal biodiversity and ecosystem functioning. Ecological engineering solutions, such as artificial fish habitats (AFH), can help rehabilitate extremely modified areas, including ports, by offering shelter for fish. As a side effect, AFH provide a substrate to benthic invertebrates and macroalgae, that could improve ecosystem functioning. The effects of AFH may also extend beyond ports and modify trophic exchange with adjacent habitats via fish feeding hydrodynamics. This thesis investigates the patterns of distribution of invertebrate biodiversity associated with AFH and explores the exchange of biomass between marinas and adjacent Posidonia oceanica meadows along the French Mediterranean coast where these habitats are often adjacent.The objectives are: (1) evaluating how taxonomic diversity and composition of benthic invertebrates vary with AFH immersion time, (2) understanding how AFH types and environmental context modify benthic assemblages, and (3) exploring the exchanges of organic matter between marinas and adjacent meadows. I focused on Biohut® AFH (ECOCEAN), made of a metal cage filled with oyster shells, attached to docks or under pontoons in harbours and marinas.In chapter 1, I examined the role of immersion time in determining the diversity and composition of invertebrate assemblages colonising AFH in 3 commercial harbours. The findings indicated significant variations in invertebrate composition from 6 to 18 months, with increased abundance, taxonomic richness, and evenness over time. In chapter 2, I focused on the geographical and within-port variability in taxonomic composition and diversity of invertebrates dwelling in AFH. The study revealed differences in taxa composition between 2 large regions, characterised by different nutrient loads and correlations between assemblage composition and chlorophyll-a, a proxy for nutrient concentration. The number of taxa was the highest in the nutrient-enriched region. Additionally, invertebrate assemblages varied according to port habitats where the AFH were placed, possibly due to differences in light availability. In chapter 3, I investigated trophic connectivity between P. oceanica meadows and adjacent marinas at 4 sites where both habitats are present. Two marinas were equipped with AFH and the remaining 2 were not. At the unequipped sites, the δ15N values of the particulate organic matter within the marina were the highest indicating human-derived nutrient enrichment. The values decreased within the meadow, gradually according to the distance. This suggests a spill of nutrients over the portion of the meadow adjacent to the inlet. Fish relied on resources from both the seagrass meadow and the marina, similarly among the 4 sites, however, the trophic niches of fishes (Diplodus spp.) captured within the equipped marina were slightly larger than those within unequipped ones and overlapped less with the trophic niches of the fish captured outside. Fish faeces were also part of the organic matter sedimenting within meadows. In chapter 4, I reported initiatives developed with other scientists. They include species functional diversity and trophic relations within AFH, acoustic signatures of organisms dwelling in AFH and biodiversity comparison between ports and marine reserves using environmental DNA.My work has highlighted several aspects that could improve the effectiveness of AFH as ecological engineering solutions. Immersion time, local environmental conditions, and specific locations within ports need particular attention. Although I did not find clear differences in cross-habitat exchange related to AFH, they seemed to play a role in reducing nutrient enrichment. Moreover, since fish play an important role in cross-habitat exchanges and find refuge within AFH, this ecological engineering solution could indirectly contribute to change trophic connectivity

Thesis (MScEng)--Stellenbosch University, 2014.<br>ENGLISH ABSTRACT: For the safekeeping or harbouring of small craft, whether for leisure or commercial use, a tranquil basin is the principle requirement in designing a functional harbour facility. Waves transmitted through the perimeter structures of a marina result in agitation of the basin and thereby a reduction in tranquillity. Similarly, waves reflected off the perimeter structures that line entrance channels could result in difficulty when manoeuvring through the entrance channel water areas. An alternative to the conventional breakwater becomes a necessity when the conventional mass-filled or caisson breakwaters are not feasible in technical or financial terms. One of the alternative options could be to consider a piled row breakwater. In broad terms, this consists of closely spaced piles that attenuate wave energy whilst not forming an impermeable barrier, allowing for currents and sediment to pass through. When comparing the different options for creating a piled row breakwater the quantity of material used to achieve a desired level of wave dissipation could be the most important aspect in considering possible alternatives, as this would relate directly to construction costs and time when considering implementation. A literature review revealed multiple references to theories that predicted the transmitted and reflected waves for various breakwater porosities and wave conditions. However, there is limited coverage in literature enabling prospective designers. For example, literature describing the applicable ranges of shape configurations that one should start off with when developing concepts is not readily available. This thesis study used physical modelling to compare the wave transmission properties of breakwaters comprised of three different piled element shapes, namely round, square and diagonal square piles. The pile element shapes are compared for varying porosity values over a range of input wave parameters. A comparison of the transmission incurred by these configurations with previous work is presented and it was found that the physical model experiment closely simulated the predicted values. The tests were scaled from actual conditions in possible marina locations and therefore the performance criteria measured could be applied in reverse to potential site locations. From analysis of the physical model results, it was clear that the highest energy loss was found, in general, to occur with low porosities (below 10%), as could be expected. For a fixed screen configuration in terms of pile element shape and porosity, the performance is heavily dependent on wave steepness, the steeper waves incurring a lower transmission coefficient than the less steep waves. For a given porosity, circular piles performed the best (transmit the least) followed by square piles and then diagonal square. When comparing the material used, diagonal square piles yielded better performing breakwaters due to the expanded cross section gained in elevation. The work has provided useful insight into the performance of piled row breakwaters in restricting transmission of wave energy. Design guidance has been provided when considering the parameters for deriving conceptual layouts for piled row breakwater structures. Recommendations were put forward for further work in this field, including potential study areas, data gathering, and study methods, as well as more applied uses of piles, for example in combination with other elements in a marina.<br>AFRIKAANSE OPSOMMING: die veilige bewaring van klein vaartuie, hetsy vir ontspanning of kommersiële gebruik, is die hoofvereiste in die ontwerp van 'n funksionele hawe fasiliteit dat die beskermde hawegebied ‘n rustende water oppervlak sal moet handhaaf. Golwe wat oorgedra word deur die omtrek golfbrekers van ‘n hawe deur middel van transmissie veroorsaak oppervlak versteurings in die hawe bak en dus ook ongewensde versteurings in die vasmeer kondisies. Op ‘n soortgelyke wyse, veroorsaak golwe wat gereflekteer word vanaf die toegangs kanaal golfbrekers problematiese kondisies vir die navigeer van bote deur die kanaal. Die behoefte aan 'n golfbreker alternatief vir die konvensionele oplossing word genoodsaak wanneer die konvensionele stortrots of caisson golfbrekers nie haalbaar is nie as gevolg van tegniese of finansiële aspekte (Park et al. 2000). Een van die opsies wat oorweeg kan word as 'n alternatief is ‘n heipaal-ry tipe breekwater. In breë terme, bestaan dit uit naby gespasieërde heipale om golf energie te breek, sonder om ‘n ondeurdringbare versperring te vorm. Wanneer die verskillende opsies vir die skep van 'n heipaal-ry tipe breekwater vergelyk word, kan die hoeveelheid konstruksie materiaal benodig per opsie die belangrikste vergelykende parameter word. Die rede hiervoor is die direkte verwantskap aan konstruksie kostes sowel as tyd aspekte wat gepaardgaan met die konstruksie materiaal hoeveelhede. Vanuit die literatuurstudie is verskeie verwysings geïdentifiseer waarin vorige teorieë oor oordrag en refleksie van golwe evalueer word vir wisselende porositeit waardes en intree golf waardes. Daar is egter 'n beperkte dekking in die literatuur wat ontwerps-riglyne betref. Byvoorbeeld, die toepaslike omvang van die vorm konfigurasies wat oorweeg moet word wanneer konsep ontwerp gedoen word, is nie geredelik beskikbaar nie. Hierdie tesis vergelyk, deur middel van fisiese skaal model toetse, drie heipaal-ry element vorms, naamlik ronde, vierkantige en diagonal geroteerde vierkante vir verskillende porositeit waardes oor 'n verskeidenheid van golf inset parameters. 'n Vergelyking is getref tussen die toetsdata en vorige werk en daar is bevind dat die fisiese model eksperiment die voorspelde waades uit die literatuur redelik akkuraat kon naboots. Die toets kondisies is geskaal vanaf werklike moontlike marina terreine en dus kon die toets resultate toegepas word in die ontwerp van potensiële terreine. Vanuit die data-analise, is waargeneem dat die hoogste energie verliese oor die algemeen plaasvind by laer porosititeit waardes (onder 10%) soos wat verwag kon word. Vir 'n gegewe golfbreker opset, in terme van die heipaal element vorm en porositeit, is die verrigting hoogs afhanklik van die golf steilheid, met hoër verrigting by steiler golwe. Vir 'n gegewe porositeit, sal ronde heipaal elemente die beste verrigting gee, gevolg deur vierkante heipale en laastens diagonal geroteerde vierkante. Vir soortgelyke hoeveelheid heipale, sal diagonal geroteerde vierkante beter verrigting lewer moontlik as gevolg van die verlengde deursnit dimensie in vooraansig. Hierdie navorsing het goeie insig verskaf oor golfdeurlaatbaarheid en weerkaatsing van heipaalry breekwaters. Ontwerp riglyne word ook verskaf wat betref die parameters wat gebruik kan word vir die konsep ontwikkelings fase vir heipaal-ry breekwaters. Aanbevelings word gemaak vir verdere navorsingswerk in hierdie veld, insluitend moontlike studie-areas, data insameling, studie metodes, sowel as vir meer toegepasde situasies, byvoorbeeld waar die heipaal elemente in kombinasie met ander marina komponente ontwerp moet word.

Turkey, with its climate, protected bays, cultural and environmental resources is an ideal place for yacht tourism. Subsequently, yacht tourism is increasing consistently. Yacht tourism can cause unmitigated development and environmental concerns when aiming to achieve tourist satisfaction. As the demand for yacht tourism intensifies, sustainable development strategies are needed to maximize natural, cultural and economic benefits. Integration of forecasts to the strategic planning is necessary for sustainable and use of the coastal resources. In this study two different quantitative forecasting techniques - Exponential smoothing and Auto-Regressive Integrated Moving Average (ARIMA) methods were used to estimate the demand for yacht berthing capacity demand till 2030 in Turkey. Based on environmental, socio-economic and geographic data and the opinions gathered from stakeholders such as marina operators, local communities and government officials an allocation model was developed for the successful allocation of the predicted demand seeking social and economical growth while preserving the coastal environment. AHP was used to identify and evaluate the development, social and environmental and geographic priorities. Aiming a dynamic plan which is responsive to both national and international developments in yacht tourism, potential investment areas were determined for the investments required to accommodate the future demand. This study provides a multi dimensioned point of view to planning problem and highlights the need for sustainable and dynamic planning at delicate and high demand areas such as coasts.

<p> Seagrass ecosystems are some of the most productive in the world and provide a variety of ecosystem services but are facing global decline chiefly due to anthropogenic disturbance. Mechanical disturbances to seagrass meadows from anchoring, propeller scars, and mooring scars result in losses or damage to both shoots and the underlying rhizome. I conducted a literature synthesis on the extent of, recovery from, and ecological impacts of these mechanical disturbances to seagrass meadows. The literature suggests that anchoring damage tends to be worst in deeper water where larger vessels anchor and can cause large (>100m²) loss per anchoring and recovery may take decades to over a century. Propeller damage is of largest concern in shallow (&lt;2m) areas experiencing heavy boat traffic because propeller damage can only occur where the propeller can come close to the seagrass. Mooring damage is highly variable depending on the type of mooring used (&lt;10m² to >1000m² scoured per mooring). Seagrass patches experiencing these mechanical disturbances have, in some studies, been found to have lower seagrass percent cover and shoot density than reference areas. This indicates scars can have &lsquo;halos&rsquo; of impacted seagrass meadow. Some seagrass systems cannot recover within a century (e.g. <i>Posidonia oceanica</i> meadows at the extent of their depth tolerance) while others recover annually from some disturbances (e.g., anchor scars &lt;1m²). Systems face altered species composition when scars are preferentially recolonized by certain species and patterns of recovery are affected by altered biogeochemical conditions following disturbances. Additionally, mooring, anchoring, and propeller scarring frequently alter meadow density, cover, patch size, patch shape, patch isolation, edge area, and ratios of edge to interior meadow leading to changes in faunal community structure. Correlations between these disturbances and faunal abundances, densities, and richness in seagrass ecosystems are complex, vary temporally (sometimes on the scale of days), and may result in species showing positive, negative, or no responses to a wide range of disturbance regimes. </p><p> To explore the connections between mooring scarring, the surrounding seagrass meadow condition and epifaunal community, in the second part of this thesis I measured 30 mooring scars to determine average scar size. To explore any potential &lsquo;halo&rsquo; effect around mooring scars for seagrass or epifauna and to seek any difference in epifaunal community between mooring and reference sites I also sampled paired sites at eight locations in Nantucket Harbor, Massachusetts three times each in the summer of 2015. Each location consisted of a meadow site actively experiencing mooring scarring and a reference site without moorings. My conservative sampling methods of the 30 sampled mooring scars found scars to average 21.1m². Across my paired sites, seagrass was found to have lower cover and lower canopy height in mooring versus reference sites. Seagrass cover and canopy height were lower in the first few meters (typically 2-3m) surrounding each scar in comparison to paired reference quadrats indicating a &lsquo;halo&rsquo; effect of each scar. I did not detect a difference in epifaunal community composition or density per blade between mooring and reference sites; however, the relatively constant per blade concentration of epifauna combined with the differences in seagrass biomass between the mooring versus reference sites indicate an overall increase in the total amount of epifauna in areas with less disturbance. Epifaunal community composition was different and between locations and sampling dates indicating these factors are more important than proximity to mooring scarring in determining epifaunal abundance and richness. When considering scar area and the &lsquo;halo&rsquo; of each scar I estimate that at least 32ha (2%) of Nantucket Harbor was impacted by mooring scarring. Given that the estimates of seagrass do not include areas previously denuded of this plant and that my measurements were conservative, likely a larger portion of this harbor&rsquo;s potential seagrass habitat is impacted. Combined with the findings of loss due to these direct boat-related physical disturbances of seagrass meadows worldwide across regions, this halo effect is likely to also be found for moorings globally. I encourage management of the issue by employing and fine-tuning mooring methods (such as deploying moorings with anchor connections that do not drag on the sea floor) to minimize these unintentional but strong effects of mooring on the recipient habitat.</p><p>

Os aspectos ambientais relacionados às atividades cotidianas de marinas de águas interiores, de terminais hidroviários de passageiros, de embarcações de lazer e de turismo e de outras instalações de apoio, como os estaleiros fluviais, indicam a necessidade da adoção de modelos sustentáveis de gerenciamento destas organizações, pois suas atividades ocorrem diretamente nos corpos d\'água e nas margens de rios e reservatórios, áreas estratégicas para o equilíbrio dos ecossistemas aquáticos e protegidas por uma legislação ambiental rigorosa. Este trabalho sugere alternativas tecnológicas e propõe a implementação de um programa de gestão de resíduos e efluentes, visando adequar a infra-estrutura e a operação de marinas, de terminais de passageiros e de embarcações de turismo, lazer e recreio, à série de normas ISO 14000 e a legislação ambiental, em relação à destinação dos resíduos sólidos, dos resíduos oleosos e dos efluentes sanitários gerados. As propostas foram fundamentadas em dados provenientes de uma avaliação sobre a situação atual das instalações receptoras, dos equipamentos e da gestão de resíduos e efluentes, realizada em uma marina e em uma empresa de navegação de turismo que operam no reservatório de Bariri, na Hidrovia Tietê-Paraná. Os resultados deste trabalho demonstram a importância da implementação de programas de treinamento e de controle dos resíduos e dos efluentes gerados nas atividades em terra e a bordo. Esses programas baseiam-se na redução da geração dos resíduos, na segregação, na reutilização e na reciclagem dos materiais, assim como na educação ambiental e no tratamento e destinação final adequada dos resíduos e efluentes, possibilitando, desta forma, a prevenção, o controle e o combate da poluição dos recursos hídricos, além de proporcionar o aumento da atratividade do empreendimento e da segurança e satisfação de usuários e de funcionários.<br>The environmental aspects related to the daily operations in small craft inland harbors, in passenger waterway terminals, in leisure and tour vessels, in addition to other supporting facilities such as fluvial shipyards, indicate the need for adoption of sustainable models of management of such organizations, due to the fact that their activities are directly related to water bodies and to river banks and reservoirs, which are strategic areas for the aquatic ecosystems balance and protected by a strict environmental legislation. This study focus on technological options and proposes the implementation of a management program of waste and sewage in order to adapt the facilities and the operation of the marinas, passenger terminals and recreational boating to the ISO 14000 serial rules and to the environmental legislation in relation to the destination of solid wastes, oily residues and sewage effluents. The proposals were based on data from an investigation about the current situation of the facilities, the equipment, and the waste and sewage management, carried on both a marina and a tour navigation company which operate in the Bariri reservoir in the Tietê-Paraná Waterway. The results of this study demonstrate the importance of the implementation of programs for training and controlling the waste and sewage produced in shore and off-shore activities. These programs are based on the reduction of the production of waste, on the segregation, on the reutilization and the recycling of the materials, as well as on environmental education and on the treatment and final destination of waste and sewage. This way, they may prevent, control and act against water resources pollution besides making business more attractive and the places safer and more appealing for users and workers.

Computer models are nowadays routinely used in harbor engineering applications. Models based on the two-dimensional elliptic mild-slope equation can simultaneously simulate refraction, diffraction, reflection, and dissipation in completely arbitrary coastal domains. However, floating structures such as floating breakwaters and docks are often encountered in the modeling domain. This makes the problem locally 3- dimensional. Hence it is problematic to incorporate a floating structure into the 2-d model. Tsay and Liu (1983) proposed a highly simplified but approximate approach to handle this problem practically. The validity of their approach is examined in detail and it is found that the actual solutions deviate considerably from the theoretical solutions, although their approximation provides results with the correct trend. Therefore, correction factors have been developed and may be used to produce more reliable results using the framework of Tsay and Liu (1983). The resulting method is applied to Douglas harbor in Alaska. The result shows that docks in the harbor distort the wave field considerably and create a reflective pattern that can affect navigation safety in some areas. Also plots are developed for the transmission coefficients for waves propagating past rectangular and cylindrical floating objects of infinite extent for a wide range of conditions encountered in practice.

Harbors are extreme examples of coastal urbanization. Artificial substrata in the Ravenna harbour are almost completely dominated by mussel beds. Mussel clumps provide substrata for small mobile fauna (meiofauna). The aim of the thesis is to study the meiofauna associated to the mussels attached to the harbour structures. Moreover, the thesis provides the basis for the construction of a local meiofaunal genetic database, with the final goal of time and cost reduction on meiofaunal assessment through a metabarcoding approach. Mussel beds and associated meiofauna were sampled in two locations of the port (North vs. South) in two types of artificial substrata (rock boulders vs. concrete seawalls) at two different times. Taxonomic assessment of the meiofauna was carried out. Mussel bed complexity was evaluated by means of different measures (e.g. weight, volume, length of valve). The main results are: 1) meiofauna assemblages are very different in the two substrata, but these differences were influenced by locations and by the sampling periods. The number of taxa and diversity index on the rock boulders, the more complex primary substratum, resulted higher than those on the seawalls. 2) Variables analysed altogether showed differences between substrata, locations and times. A weak correlation was found between the mussel bed descriptors and the associated meiofauna assemblages. The number of structural mussels and the mean size lengths resulted responsible for the relationship. These results suggest that other measures of mussel complexity are needed, and that meiofauna assemblages vary depending on different substrata and to abiotic conditions associated to the locations (e.g. marine currents, exposition-to-sun). The genetic research identified a lack of sequences of species from the Adriatic Sea, especially for the “permanent” meiofauna. Alignment of the available sequences identified in the V7 and V8 regions of the SSU_18S a good target for meiofaunal barcoding.

Coastal urbanization is resulting in shorelines being increasingly built-over and protected by artificial structures which are generally colonized by species poor assemblages dominated by opportunistic organisms. “Eco” approaches integrating ecological research into the design of these structures, such as enhancing substrate complexity and seeding of surfaces with target organisms, provide the chance to improve the structure and function of target-designed novel ecosystems. I tested the effects of two design techniques, specifically tiles mimicking increasing substrate complexity and seeding of habitat forming oysters, on the development of benthic intertidal assemblages at two jetty sites of Ravenna’s port. I used orthogonal combinations of different complexity tiles (flat, 2.5 cm high ridges tiles and 5 cm high ridges) and two seeding conditions (unseeded and seeded with oyster recruits), and measured the developing assemblages over the first 6 months. I also analysed the effect of substrate complexity on seeded oyster survivorship and growth. A great difference between the assemblages at the two sites was detected due mostly to higher presence of algae at the southern site and bare substrate at the northern site. Lower abundance of the opportunistic algae Ulva spp. and Cladophora sp. were registered on more complex tiles. The same algae were more abundant on unseeded tiles. The seeded oysters reduced the presence of opportunistic species by both space pre-emption and by creating biogenic microhabitats. No effects of substrate complexity was observed on oyster survivorship and growth. These results suggest that both increasing substrate complexity and seeding could help reducing the presence of opportunistic species on port structure in the short term. Longer-term observations will be needed to explore the efficacy of these interventions over longer times and their practical applications on port seawalls and other types of artificial structures.

The increase of human population and their pressures in coastal areas is causing an exponential sprawl of artificial structures in marine areas, leading to the loss of natural habitats. Artificial structures are characterised by low species richness and a prevalence of non-native species compared to natural rocky reefs. Commercial and tourist ports are examples of artificial habitats. Little is known about the distribution and dynamic of the species inhabiting ports, and the factors leading to a prevalence of non-native species in these habitats are still not fully understood. Here, the distribution and abundances of two native (Mytilus galloprovincialis, Ostrea edulis) and two non-native (Xenostrobus securis, Crassostrea gigas) bivalve species that grow on the artificial seawalls of the canal-port of Ravenna were assessed to: 1) explore their distribution in different areas of the harbour, and 2) identify whether the observed patterns were related to variations in environmental parameters or to variable supply of larvae reaching different areas of the port and settling on the artificial seawalls. DNA extraction and amplification protocols were developed to barcode the bivalves settlers due to the impossibility to identify them microscopically. Results showed an increase of non-native species as the canal-port goes inland. Temperature, oxygen and nitrate seawater concentration explained most of the variation in species abundance among sites. The non-native mussel X. securis was associated to higher sea surface temperatures compared to the native M. galloprovincialis. Settler abundances were clearly correlated to the spawning window of the species, but not to adult abundances on the seawalls, suggesting a prevailing role of post-settlement processes. Future work should explore the potential role of other environmental variables, extend the duration of the observations, and use a metagenomics approach to characterise propagule pressure dynamics in the water column.

L'image du port mal famé est un thème reconnu dans la culture contemporaine. Elle se construit autour des bouges des quais, des marins en bordée et des prostituées. Ils déterminent la représentation des bas-fonds portuaires, continuité des lieux de misère, du vice et du crime. Espaces spécifiques des villes, leur image est construite par la littérature et la presse, au milieu du XIXe siècle. L'héritage de vision négative des ports, les récits de flibuste, la défiance envers les marins construisent leur représentation. Les bas-fonds de l'Ouest de la France s'inscrivent dans un univers plus large : celui des marins déviants, des quartiers mal famés des villes mais aussi d'une province arriérée et dangereuse. Dans le premier XIXe siècle, les mauvais lieux du rivage en cumulent les caractéristiques. Dans les années 1880, le port, révélé par la bordée, focalise l'attention des romanciers. En parallèle, la misère et l'insécurité constituent des thèmes privilégiés pour la presse, les observateurs sociaux et les autorités. Les figures de l'homme de mer, des prostituées, des soldats, des miséreux et des criminels jouent un rôle central de fascination et de condamnation. Cet univers revendique ses codes. La disparition des bas-fonds est annoncée dès l'entre-deux-guerres. L'effacement des mystères de la mer laisse place à la nostalgie des observateurs de la vie maritime. Leur mémoire perdure alors après la Seconde Guerre mondiale<br>The image of ill-reputed harbour is a common pattern in modern culture. It's built on harbour's slum, sailor's bender, prostitutes and docks, that define the representation of this area. This image echoes other places of misery, vice and crimes. The representation of those harbour's slums, that occupy specific neighborhoods in cities, are created by writers and journalists in mid-19th century. This image is also the legacy of negative vision of port, of buccaneering's stories and sailor's distrust. The harbour's slum is part of a broader universe : sailors with deviant behaviour, ill-reputed neighborhood, backward and dangerous province. During the first part of the 19th century, some places of the coastline have rough reputation but in the 1880's, the novelists, who discover sailor's bender, focus on ports. At the same time, journalists, social commentators and authorities focus on misery and insecurity. Seafarers, who claim his belongings to the slums, prostitutes, soldiers, the poor and criminals play a central role in the fascination and the condemnation of the harbour's slum. During the inter war period, the harbour's slum is seen as dying out. As the mystery vanishes, the nostalgia begins, that lasts after World War II

Il porto di Ravenna rappresenta uno dei più grandi porti commerciali Italiani. Si tratta di un ambiente urbanizzato e soggetto ad un’intensa circolazione navale e quindi soggetto a inquinamento e introduzione di specie aliene. La biodiversità in questo ambiente è relativamente alta e include i molluschi bivalvi, specie utilizzata per il biomonitoraggio di contaminanti ambientali grazie alla loro ampia distribuzione, vita sessile, attività di filtrazione e facilità di campionamento. Lo scopo di questo studio è quello di utilizzare i mitili come bioindicatori di contaminazione virale nel porto di Ravenna e nel tratto di mare antistante, considerando sia la variabilità spaziale che quella temporale. In particolare, è stata investigata la presenza di virus umani come il Norovirus (NoV) e il virus dell’epatite A (HAV) e del virus della Necrosi Nervosa (NNV) responsabile nel periodo estivo di focolai di mortalità nei pesci allevati. L’indagine ha mostrato la presenza di contaminazioni da virus umani nei mitili raccolti nella parte più interna del porto con una maggiore contaminazione da NoV nei mesi invernali, similmente a quanto osservato in altre aree. La genotipizzazione dei virus trovati ha mostrato la presenza di ceppi multipli di NoV che rappresentano quelli più diffusi a livello mondiale. È stata inoltre rilevata la presenza di HAV IA, genotipo già isolato in infezioni umane associate al consumo di prodotti ittici crudi. Invece, mitili contaminati da NNV sono stati rilevati in tutti i siti campionati, incluse le piattaforme offshore, mostrando un’ampia diffusione di questo virus. La maggior parte delle contaminazioni da NNV è stata evidenziata durante il periodo estivo. La genotipizzazione ha mostrato la somiglianza dei virus evidenziati con ceppi di NNV precedentemente trovati in pesci e in molluschi bivalvi nel mar Adriatico. Questi risultati suggeriscono che i mitili abbiano accumulato l’NNV rilasciato da pesci selvatici infetti che vivono in quest’area.

La côte ouest irlandaise située dans les comtés de Clare et Galway est depuis récemment affectée par une augmentation de la fréquence des inondations et une montée du niveau marin. L'impact de ces changements climatiques se fait particulièrement ressentir au niveau des aquifères karstiques côtiers de ces régions, tel que le bassin karstique de Bell Harbour (~50 km²) sélectionné dans le cadre de ce projet: le positionnement d'un biseau salé dans cet aquifère est clairement dû à l'interaction entre sa recharge liée aux événements pluvieux et la forte influence de la marée. Des données (niveaux d'eau et conductivités spécifiques) ont été collectées à l'aide de sondes, à deux sources côtières, six forages, trois lacs et au milieu de la baie durant des périodes prolongées. Trois types d'environnement hydrodynamiques (conduits, fissures et matrices) ont été définis pour chacun des six forages en comparant deux méthodes qui se sont avérées cohérentes entre-elles. Les variations des conductivités spécifiques combinées à la chimie des eaux des six forages et de lacs ont permis d'évaluer l'étendue du biseau salé dans l'aquifère en fonction de la recharge de l'aquifère et des cycles de marée haute/basse et vives eaux/basses eaux: l'étendue du biseau salé dépend des propriétés hydrodynamiques de l'aquifère mais aussi de l'influence relative de la recharge et de la marée sur les niveaux piézométriques, induisant chacun des comportements opposés. Ainsi, la compétition entre la recharge et la marée contrôle l'intrusion d'eau de mer dans l'aquifère, ce qui explique les changements spatio-temporels du biseau salé dans l'aquifère. Les fortes amplitudes de marée semblent être le moteur des brèves intrusions salines dans l'aquifère proche de la rive alors que la position du niveau piézométrique semble influencer l'intensité de cette augmentation de la salinité. La recharge karstique de la région est suffisamment importante tout au long de l'année pour que le biseau salé ne s'étende pas plus loin qu'un kilomètre de la rive. La diminution des précipitations durant l'été (~10 %) ainsi que l'augmentation du niveau marin prévues pour les prochaines décennies, contribueront certainement à une intrusion plus importante du biseau salé dans l'aquifère<br>Low-lying coastal areas in the west of Ireland, such as the Galway and Clare coasts, have seen recent increases in flooding frequencies coupled with overall increases in sea level. The impacts of these changes are most strongly felt in coastal karst catchments and this study focuses on one such area, the Bell Harbour catchment (~50 km²), where there is a clear interaction between rainfall inputs and tidal influences, to create a terrestrial salt water wedge. Data (specific conductivity and water levels) have been collected at two coastal springs, six boreholes, three lakes, and from discrete locations in the middle of the bay, using dedicated loggers over extended periods. Two approaches that provided consistent results were used to explain the different hydrodynamic behaviours identified in the boreholes (conduits, fissures and matrix flows). Specific conductivity variations and water chemistry measured inland allowed for assessment of the spatial extent of the saltwater wedge into the aquifer as a function of both karst recharge and tidal movements at high/low and neap/spring tidal cycles. The extent of the saltwater wedge depends on the intrinsic properties of the aquifer but also on the relative influence of the recharge and the tide on groundwater levels, which induce opposite behaviours. This dynamic between recharge and the tide thus controls the seawater inputs, hence explaining temporal and spatial changes in the saltwater wedge in this coastal karst aquifer. Strong tidal amplitudes seems to be the motor of sudden saltwater intrusion observed in the aquifer near the shore while the relative elevation of the groundwater appears to influence the intensity of the salinity increase. The magnitude of annual recharge in the area is high enough to limit saltwater intrusion to no more than about one kilometre inland from the shore. Given the anticipated decreases in summer precipitation (~10 percent), coupled with anticipated sea level rises, the extent of the saltwater wedge into the aquifer is likely to increase in coming decades

Dans le cadre de cette thèse en archéologie grecque, j’ai entrepris de travailler sur l’organisation du commerce maritime grec en Méditerranée orientale et en mer Noire aux Vème et IVème s. av. J.-C., et principalement sur la nature et l'intensité des échanges qui s'opéraient dans cette partie de la Méditerranée à l'époque. Pour mener à bien mon travail, j'ai constitué un nouveau catalogue des épaves grecques que j'ai ensuite confronté aux sources textuelles, épigraphiques, et archéologiques existantes. L'étude attentive des cargaisons des bateaux à laquelle je me livre participe à une meilleure compréhension des acteurs commerciaux de l'époque, des réseaux d'échanges et surtout du véritable rôle joué par Athènes<br>In this present thesis concerning Greek Archaeology, I undertook to work on the organization of Greek maritime commerce in Eastern Mediterranean and Black Sea during the 5th and 4th century BC. I worked mostly on the trade's nature and intensity occurring in this part of the Mediteranean in this time. In order to carry out my work properly, I established a new catalog of greek shipwrecks, that I then confront with textual, epigraphic and archaeological sources. The careful study of the ship's cargo takes part in a better understanding of the commercial actors, trading network and above all of the importance of Athens at this time

Le phoque veau-marin (Phoca vitulina) et le phoque gris (Halichoerus grypus), deux espèces sympatriques de mammifères marins, sont de plus en plus considérés comme des compétiteurs potentiels, et ce plus particulièrement au cœur de leur distribution européenne. L’objectif de cette thèse est d’étudier les stratégies de chasse et l’écologie trophique de ces espèces en limite de leur aire de distribution (baie de Somme, Manche Est, France), et d’explorer l’hypothèse de compétition interspécifique. Des outils de bio-télémétrie ont été déployés sur 49 individus afin d’obtenir des données sur leurs déplacements et plongées en mer. L’analyse des localisations en surface et du comportement en plongée, complétée plus récemment par la détection de tentatives de captures de proies (accélérométrie), a permis de mieux comprendre les stratégies de chasse de ces espèces, et d’améliorer la détection des zones de chasse. Les niches trophiques des deux espèces de phoques ont ensuite été caractérisées par analyse du régime alimentaire, des isotopes stables (vibrisses des mêmes individus capturés), et des zones de chasse. Un important chevauchement interspécifique a été identifié entre ces niches, résultant de la consommation de poissons plats benthiques en zone côtière, ce qui apporte ici le contexte informatif d’une potentielle compétition. Cette étude montre aussi le rôle clé des stratégies individuelles de chasse sur les conclusions écologiques à l’échelle de l’espèce/sous-population,dont la potentielle compétition qui serait induite par certains phoques gris. La poursuite des suivis est nécessaire pour détecter tout potentiel changement écologique dont l’origine serait trophique<br>Harbour seal (Phoca vitulina) and grey seal (Halichoerus grypus) are two sympatric marine mammal species that are increasingly considered as potential competitors, especially at their European core distributions. The objective of this PhD was to study the foraging strategies and trophic ecology of these species at the limit of their range (Baie de Somme, Eastern English Channel, France), and to investigate the hypothesis of potential interspecific competition. Biotelemetry devices were fitted on 49 individuals to document their movements and dives at sea.The analysis of surface locations and diving behaviour, completed recently by the detection of Prey Capture Attempts (accelerometry), allowed for a better understanding of the two seal species’ foraging strategies and improved the detection of their foraging areas. Trophic niches of the two seal species were then characterised with the analysis of diet, stable isotopes (in the whiskers of the same captured individuals), and foraging areas. A high interspecific trophic overlap was identified between these niches, resulting from the consumption of benthic flatfish in coastal areas, and we suggest that it provides here the basis for potential competition between both species. This study also showed the key role of individual foraging strategies on the ecological conclusions at the scale of the species/sub-population, including that the potential competition may be due to some individual grey seal strategies. Continuing these studies is essential to detect any potential ecological changes that could be trophically-induced

Dissertação de Mestrado, Estudos Integrados dos Oceanos, 18 abril de 2019, Universidade dos Açores.<br>O boto e um pequeno predador marinho com um elevado estatuto de conservação nas águas europeias. Para uma proteção eficaz desta espécie é importante ter conhecimentos detalhados das respostas comportamentais as mudanças das condições ambientais. Neste estudo, investiguei a influência das condições ambientais sobre a variação do comportamento de deslocação de grande escala da população de botos no Mar do Norte. Foram analisados dados de deslocações de 57 indivíduos rastreados por satélite num período de 19 anos. Para cada relocalização, estimou-se o estado comportamental subjacente do indivíduo (residência ou em deslocação) recorrendo a processos de modelação do estado espacial (State-space modelling, SSM). Estes estados comportamentais foram então correlacionados com variáveis ambientais estáticas e dinâmicas através de regressões logísticas. Estimou-se que os botos estão cerca de 81% do seu tempo em áreas circunscritas, passando apenas uma pequena parte do seu tempo (6%) em rápidas deslocações de longa distância, classificadas como estado de deslocação. Esses movimentos de curta duração e longas distâncias refletem provavelmente deslocações entre áreas de procura de alimentação. As restantes relocalizações (13%) não puderam ser atribuídas sem ambiguidade a nenhum destes estados comportamentais. Foram encontradas diferenças individuais consideráveis na extensão destas deslocações, com máximos variáveis entre 24 km e 867 km, relativamente à posição inicial. Consequentemente, a proporção de tempo gasto no estado de deslocação rápida (variando de 0,5% até 20,0%) e no estado residente (variando de 50,5% ate 99,5%) foi altamente variável entre indivíduos. O estado residente foi associado com baixos níveis de salinidade, temperatura e velocidade da corrente; com altas concentrações de clorofila-a em relação à media sazonal; e com declives intermédios do fundo. Estes resultados indicam indiretamente que as presas dos botos provavelmente se agregaram em áreas com as condições ambientais referidas, servindo, portanto, como área de alimentação. Estudos anteriores sobre a distribuição e abundância dos botos suportam a importância desses fatores ambientais. Os conhecimentos adquiridos neste estudo podem ser usados para melhorar os modelos populacionais espaciais que estão atualmente a ser desenvolvidos para estudar o impacto do ambiente marinho em mudança, e com as crescentes perturbações antrópicas, que afetam a dinâmica da população de botos.<br>ABSTRACT: The harbour porpoise is a small marine predator with a high conservation status in European waters. In order to protect the species effectively, it is crucial to acquire detailed knowledge on behavioural responses to changing environmental conditions. Here, I investigated the influence of environmental conditions on variation in large-scale movement behaviour of the harbour porpoise population in the North Sea. The movement tracks of 57 satellite- tracked individuals tagged over a total period of 19 years were analysed. For each relocation, the underlying behavioural state (area-restricted or transient state) of the individual was estimated using a state-space modelling (SSM) approach. The behavioural states were then modelled as a function of multiple static and dynamic environmental variables by means of a logistic regression. Harbour porpoises were estimated to spend about 81% of their time in area-restricted state (i.e. movements within feeding areas), while they spent only a small amount of their time (6%) in making fast and long-ranging movements, classified as transient state. These short movement bursts over long distances likely reflected transient movements between foraging grounds. The remaining relocations (13%) could not be assigned unambiguously to either state. Considerable individual differences in the extent of movements were found, with the maximum net displacement from the first location ranging from 24 km to 867 km. Accordingly, the proportion of time spent in transient state (ranging from 0.5% to 20.0%) and resident state (ranging from 50.5% to 99.5%) was highly variable among individuals. The area-restricted state was associated with low levels of salinity, temperature and current velocity; with high levels of chlorophyll a concentrations relative to the seasonal mean; and with intermediate sea bottom slopes. These results indirectly indicate that prey species may aggregate in areas where such environmental conditions are found, therefore serving as feeding grounds to harbour porpoises. Earlier studies on harbour porpoise distribution and abundance support the importance of these environmental drivers. The findings from this study can be used to better inform spatially explicit population models that are currently being developed to study the impact of a changing marine environment with increasing anthropogenic disturbance on harbour porpoise population dynamics.