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Dissertations / Theses on the topic 'Coastal ecology'
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Suluvale, Eletise Taauta. "The role of contaminants in altering the coastal environment of Samoa /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phs954.pdf.
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McArthur, Victoria Ellen. "The ecology of East Anglian coastal lagoons." Thesis, University of Cambridge, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627535.
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Chu, Wai-yan Cherry. "Effect of submarine groundwater discharge on coastal ecology /." View the Table of Contents & Abstract, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36616734.
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Chu, Wai-yan Cherry, and 朱慧欣. "Effect of submarine groundwater discharge on coastal ecology." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B45014346.
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Fungomeli, Maria Mashirma <1977>. "Coastal Forests of Kenya-Ecology, Biodiversity & Conservation." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9877/3/Fungomeli_Maria_PhD_Thesis_Coastal_Forests_of%20_Kenya_Final_2021.pdf.
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Aims: the broad objective of this study is to investigate the ecological, biodiversity and conservation status of the coastal forests of Kenya fragments.
The specific aims of the study are:
(1) to investigate current quantitative trends in plant diversity; (2) develop a spatial and standardised vegetation database for the coastal forests Kenya; (3) investigate forest structure, species diversity and composition across the forests; (4) investigate the effect of forest fragment area on plant species diversity; (5) investigate phylogenetic diversity across these coastal remnants (6) assess vulnerability and provide conservation perspectives to concrete policy issues; (7) investigate plant and butterfly diversity correlation.
Methods: I performed various analytical methods including species diversity metrics; multiple regression models for species-area relationship and small island effect; non-metric multidimensional scaling; ANOSIM; PERMANOVA; multiplicative beta diversity partitioning; species accumulation curve and species indicator analysis; statistical tests, rarefaction of species richness; phylogenetic diversity metrics of Phylogenetic diversity index, mean pairwise distance, mean nearest taxon distance, and their null-models: and Co-correspondence analysis.
Results: developed the first large standardised, spatial and geo-referenced vegetation database for coastal forests of Kenya consisting of 600 plant species, across 25 forest fragments using 158 plots subdivided into 3160 subplots, 18 sacred forests and seven forest reserves; species diversity, composition and forest structure was significantly different across forest sites and between forest reserves and sacred forests, higher beta diversity, species-area relationship explained significant variability of plant diversity, small Island effect was not evident; sacred forests exhibited higher phylogenetic diversity compared to forest reserves; the threatened Red List species contributed higher evolutionary history; a strong correlation between plants and butterfly diversity.
Conclusions: This study provides for the first time a standardized and large vegetation data. Results emphasizes need to improve sacred forests protection status and enhance forest connectivity across forest reserves and sacred forests.
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Lønborg, Christian. "Bioavailability of dissolved organic matter in coastal waters." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=59094.
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Magnusson, Gisele Marie. "Economic-ecological relationships in coastal wetland restoration /." View online ; access limited to URI, 2006. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3225321.
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Olquín, Irma. "Speciation in marine systems : the case study of the sea urchin Arbacia incisa (Agassiz 1863) /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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Thesis (Ph. D.)--San Diego State University, and University of California, Davis, 2003.<br>Includes bibliographical references (leaves 65-72). Also available via the World Wide Web. (Restricted to UC campuses)
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Bailey, Susan K. "Tributyltin (TBT) contamination in Scottish coastal waters." Thesis, Edinburgh Napier University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292212.
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Tai, Koon Keung. "Ecological status and conservation value of soft shore habitats in Hong Kong /." access full-text access abstract and table of contents, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?mphil-bch-b19885970a.pdf.
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Thesis (M.Phil.)--City University of Hong Kong, 2005.<br>"Submitted to Department of Biology and Chemistry in partial fulfillment of the requirements for the degree of Master of Philosophy" Includes bibliographical references (leaves 143-161)
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Tang, Wai-wah. "A review of habitat loss and coastal development of Hong Kong with special reference to Lantau Island." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B4378432x.
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Gebe, Zimkhita. "The ecology of picophytoplankton in a coastal upwelling ecosystem." Doctoral thesis, Faculty of Science, 2021. http://hdl.handle.net/11427/33737.
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The dynamic Benguela Upwelling System is one of four major upwelling regions in the world and is subdivided into two sub-systems, the northern and southern Benguela. This current study was conducted within the southern Benguela, which lies between 27°S and 35°S (Orange River Mouth to East London) and is characterized on the west coast by seasonal, wind-driven, coastal upwelling. The study targeted three picophytoplankton groups, Synechococcus, Prochlorococcus and picoeukaryotes, which are the three most abundant < 2 µm size class phytoplankton. Flow cytometry was employed to enumerate picophytoplankton abundances, using their pigments and cell sizes to identify the different groups. The aim of the study was to investigate the role of picophytoplankton in the southern Benguela coastal upwelling ecosystem. These aims were met by: i) determining the spatiotemporal variability of each of the three picophytoplankton groups over a period of 8 sampling cruises at 44 stations across four latitudinal lines in the study region, ii) determining short-term changes in carbon and nitrogen biomass of picophytoplankton and their growth rates over a 10-day period, using abundance estimates from a station off St. Helena Bay, and iii) estimating mortality of microbial communities in a laboratory study using samples collected from a coastal upwelling environment. Results showed no strong seasonality in picophytoplankton abundances but evidence of latitudinal and zonal effects. Investigations over the short term showed that populations of picophytoplankton in the southern Benguela change on the same timescale of ~3 days as the larger phytoplankton during an upwelling event. Determining mortality rates using a dilution experiment presented some challenges. Instead of increased growth rates, the study showed decreased growth rates as predator numbers decreased. These shortcomings were investigated in a second experiment, which both excluded large predators (<200µm) and also ran a parallel experiment excluding smaller predators (10-200 µm). The last of these experiments resulted in increased growth rates as predator numbers decreased. The complexity of the southern Benguela system, with its pulsed, high productivity and large concentrations of nutrients, traditionally is known to show variability through effects on the biology of large phytoplankton. However, picophytoplankton also were variable in the study area, resulting from bottom up effects of the environment, confounded by biotic factors such as predation, parasitism and competition
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Avis, Anthony Mark. "Coastal dune ecology and management in the Eastern Cape." Thesis, Rhodes University, 1993. http://hdl.handle.net/10962/d1003753.
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The importance of understanding the ecological functioning of coastal dune systems is emphasized as being fundamental to the correct management of the dune landscape. Dune vegetation along the Eastern Cape coastline, from Cape St Francis in the west to Kei Mouth in the east was described in terms of the distribution and phytochorological affinities of the taxa. At a regional scale species distribution was strongly influenced by both the climate, particularly rainfall, and the phytochorological affinities of the taxa. Seven communities were defined using TWINSPAN, and the interrelationships between these communities in anyone area appeared to be linked to a successional gradient. Dune Slacks are thought to play a key role in this successional sequence, and a temporal study of this community led to a conceptual model of plant succession in these dunefields. Climate, particularly rainfall and wind, are major factors influencing plant succession. Wind-borne sand causes the slacks to migrate in an easterly direction under the influence of the predominantly westerly winds, although easterly winds, mainly in summer months may reverse these trends. Autogenic changes appeared to be important in this succession, and a comparative study of a good example of a primary succession at Mtunzini in Natal was undertaken to elucidate the main mechanism of change. Eight communities that were identified here were concluded to be distnbuted along a gradient of increasing age, with successional changes predictable, linear and directional. Species were grouped in distinct zones along the continuum and edaphic changes (decrease in soil pH, increase in organic matter and exchangeable bases) were related to the community based changes in species composition. The mechanism of change supported the facilitation model of plant succession which is a modification of the original Clementsian concept. Similar results were found in the Eastern Cape, but due to the harsh environment, multiple pathways of succession exist. Data from this study lent support to the model of plant succession developed earlier, and confinned that the dune slacks played an important role in this facilitation by acting as centres of diversity. The foredunes were found to have an indirect role in protecting these slacks from salt spray and sand movement. The central theme of the management studies was to investigate the ecological consequences of recreational pressure within the dune environment. Current levels of beach utilization at East London were lower than other beaches in South Africa, but a general trend of increasing utilization due to sociopolitical changes can be expected. The suitability of questionnaire surveys to assess aspects such as the adequacy of facilities, perceptual carrying capacity and the beach users opinion of natural vegetation and preference for particular beaches was demonstrated. The dune vegetation was found to be sensitive to human trampling, but at current levels, the ecological carrying capacity will not be exceeded since results of the aerial census counts and questionnaire survey revealed that few people entered sensitive zones such as the coastal forest. More detailed long term studies on the susceptibility of dune vegetation to both trampling and off-road vehicle impacts revealed a low resilience of dune plant communities to these effects. Although susceptibility differed between the three communities tested, generally the greatest amount of damage occurred after the first few passages, and vehicles caused a more significant decrease in height when compared to trampling. Recovery rates were slow and low levels of repeated damage were sufficient to retard or prevent the recovery of the plants. Stricter control of vehicle use on beaches is therefore required, and in high use zones the ecological carrying capacity should be increased by providing access tracks if possible, or if not possible, by restricting access. A historical account of the process of dune stabilization showed that although first initiated in 1845, indigenous species were only used in the past three decades. The use of alien species has resulted in problems such as a reduction in the ecological integrity and aesthetic appeal of coastal systems. The techniques applied in the stabilization of drift sands with indigenous vegetation have been successful, as revealed by a quantitative survey of 17 sites in the Eastern Cape. Sites were grouped by multivariate analysis on the basis of their species composition, and variability between sites was dependent on the types of species planted. Selection of suitable species is therefore important and is discussed with respect to their natural distribution along the coast. The long term objective of stabilization should be the creation of functional, diverse, aesthetic ecosystems, since the intrinsic and economic value of the dune landscape for tourism lies therein. However, detailed studies should be undertaken prior to implementing a manipulative process such as dune stabilization, since ecological processes may be disrupted. An understanding of such processes is therefore important if one wishes to effectively manage the dune landscape.
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Hall, Alice. "The ecology and ecological enhancement of artificial coastal structures." Thesis, Bournemouth University, 2018. http://eprints.bournemouth.ac.uk/30570/.
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Due to predicted sea level rise, increased storm frequency and coastal urbanisation, artificial coastal structures are proliferating worldwide. It is now vital to understand the impact that artificial structures are having on the marine environment and it is becoming increasingly necessary to incorporate ecologically enhanced designs into both new and existing coastal infrastructure. This thesis examines the communities associated with coastal artificial structures and trials ways in which we can improve the habitat provided for marine organisms. Firstly, the existing communities present on wooden and rock groynes within four regions along the south coast of England were surveyed and quantified and compared to natural rocky shores. The groynes were found to be less diverse than the natural rocky shores yet the wooden groynes supported a greater variety of species compared to the rock groynes. Secondly in order to assess the stability of individual populations, the variation in recruitment and mortality of the barnacle Semibalanus balanoides, and recruitment of the limpet Patella vulgata and the mussel Mytilus edulis were monitored on wooden and rock groynes within two regions and compared to natural rocky shores. High spatial variation in recruitment was observed, yet overall, communities on the groynes were comparably stable to those on the natural rocky shores. This thesis also investigates the impacts of artificial structures on surrounding mobile communities and their contribution into the food web. Baited Remote Underwater Video (BRUV) and Stable Isotope Analysis (SIA) were used to assess the distribution of mobile fauna around pleasure piers and to determine if the mobile fauna were using the pier as a feeding resource. The results showed a greater number of species in close proximity to the pier and the SIA found evidence of links between trophic levels of species collected on and around the piers. In order to assess the connectivity between populations, hydrodynamic and particle tracking models were used to determine the potential for artificial structures to act as stepping stones for the dispersal of native and non-native species. As the majority of artificial structures are known to lack biological diversity, this thesis explores how increasing the surface heterogeneity of rock armour using low cost enhancement options and improving water retention on seawalls by attaching artificial rock pools can improve diversity. The ecological enhancements attracted new species including mobile fauna which were previously absent and increased the overall diversity of the structures. To conclude the key findings are summarised and future work and management advice is outlined.
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Fruchter, Jesse. "DO LARGE, INFREQUENT DISTURBANCES RELEASE ESTUARINE WETLANDS FROM COASTAL SQUEEZING?" OpenSIUC, 2012. https://opensiuc.lib.siu.edu/theses/923.
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As disturbance frequencies, intensities, and types have changed and continue to change in response to changing climate and land-use patterns, coastal communities undergo shifts in both species composition and dominant vegetation type. Over the past 100 years, fire suppression throughout the Northern Gulf of Mexico coast has resulted in shifts towards woody species dominance at the expense of marsh cover. Over the next 100 years, sea levels will rise and tropical storm activity is projected to increase; resultant changes in salinity could reduce cover of salt-intolerant fresh marsh species. Together, the effects of fire suppression upslope and rising salinities downslope could "squeeze" fresh marsh species, reducing cover and potentially threatening persistence. To mitigate the effects of fire suppression, the use of prescribed fire as a management tool to mimic historic conditions is becoming increasingly widespread and will likely gain further popularity during the 21st century. Ecological shifts that will result from changing disturbance regimes are unknown. It was hypothesized that two recent hurricanes, Ivan and Katrina in 2004 and 2005, respectively, and a prescribed fire, in 2010, differentially affected species along the estuarine gradient and drove overall shifts away from woody dominance. Overall community composition did not change significantly in the intermediate and fresh marsh zones. However, significant changes occurred in the salt and brackish marshes and in the woody-dominated fresh marsh-scrub ecotone zones. Relative to 2004, woody species abundance decreased significantly in all zones in 2006, following Hurricanes Ivan and Katrina, and 2012, following the hurricanes and fire, though woody species regeneration in the marsh-scrub ecotone had begun to occur by 2012. It is hypothesized that interacting changes in fire and tropical storm regimes could release upslope areas from coastal squeezing.
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Nydahl, Anna. "Coastal microbial respiration in a climate change perspective." Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-62734.
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In a climate change perspective increased precipitation and temperature are expected which should influence the coastal microbial food web. Precipitation will have a strong impact on river flow and thereby increase the carbon input to the coastal zone as well as lowering the marine salinity by dilution with freshwater. Simultaneously temperature may increase by 2-5 °C, potentially influencing e.g. metabolic processes. Consequences of this have been evaluated in this thesis with focus on microbial respiration in paper II and IV. A temperature increase of 3 °C will have a marked effect on microbial respiration rates in the coastal zone. The effect of temperature on microbial respiration showed a median Q10 value of 25 with markedly higher values during winter conditions (around 0°C). These Q10 values are several-fold higher than found in oceanic environments. The conclusion was in accordance with a consistent temperature limitation of microbial respiration during an annual field study, however, shifting to DOC limitation at the elevated temperature. Neither bacterial production nor phytoplankton production showed a consistent temperature effect, suggesting that the biomass production at the base of the food web is less sensitive to a temperature increase. Results from both a field study and a fully factorial microcosm experiment supported the conclusion. Our results suggested that areas dealing with hypoxia today will most likely expand in the future, due to increased respiration caused by higher temperatures and larger riverine output of dissolved organic carbon. Pelagic respiration measurements in the sea are relatively scarce in the literature, mainly due to the lack of sufficiently good and user friendly techniques. New methods such as the dynamic luminescence quenching technique for oxygen concentration have been developed. This makes it possible to obtain continuous measurements of oxygen in an enclosed vial. Two different commercially available systems based on the dynamic luminescence quenching technique were evaluated from the aspect of precision, accuracy and detection limit when applied to respiration measurements in natural pelagic samples. The Optode setup in paper III showed a practical detection limit of 0.30 mmol m-3 d-1, which can be applied to measure respiration in productive coastal waters (used in paper IV). This included development of a stopper where the sensor was attached, stringent temperature control, proper stirring and compensation for an observed system drift. For controlled laboratory experiments with organisms smaller than 1 µm the Sensor Dish Reader (paper I) has sufficient detection limit of (4.8 mmol m-3 d-1). This required a stringent temperature control and manual temperature correction. The Sensor Dish Reader gives the opportunity to perform multiple treatments at low cost (used in paper II), but the precision is too low for field studies due to the between ampule variation.<br>Östersjön är ett brackvatten hav som sträcker sig från Bottenviken i norr till de danska sunden i söder och omsluts av en landmassa som representeras av nio länder. Denna miljö är på många sett unik genom stor sötvattenpåverkan och litet utbyte med världshaven (30 års omsättningstid). Östersjön utsätts framförallt för tillförsel av ämnen från såväl naturliga som antropogena aktiviteter. Något som ofta uppmärksammas är problem med syrefria områden och döda havsbottnar. Detta anses påverkas av både klimatförändringar och övergödning. En av de biologiska prosesser som påverkar syresituationen i haven är respiration, syreförbrukning, som utförs av de flesta levande organismerna i Östersjön. Den här avhandlingen presenterar resultat på hur bakteriers syreförbrukning påverkas av de förändringar vi förväntar oss i vårt klimat i framtiden. Det är framförallt ökad temperatur och ökat vattenflöde i våra floder som i sin tur leder till snabbare omsättning och tillförsel av näring åt bakteriesamhället. Resultaten från artiklarna II och IV visar att den potentiella temperaturökningen som väntas skulle öka syreförbrukningen i kustnära områden. Den blir extra stor i kustområden, troligen på grund av stor tillgång på organiskt material från älvarna. Även den högre tillförseln av näringsämnen kan ökan syreförbrukningen enligt artikel II. De områden som idag är syrefattiga kommer på grund av detta att expandera, framförallt längs kusterna där nya områden kan uppstå. Eventuellt kan det vara en förklaring till den ökande ytan av syrefria bottnar i i Östersjön och världshaven. För att kunna utföra mätningar av syreförbrukning krävs väldigt precisa och gärna användarvänliga metoder som lätt kan tillämpas i fält. I avhandlingen presenteras hur två olika mätmetoder optimeras för att göra tillförlitliga förbrukningsmätningar av syre. Ny teknik gör att syrehalten kan mätas med en ljusbaserad metod som skiljer sig från dagens kemiska bl.a. genom att resultaten kan följas löpande på en dator. De båda metoderna kräver en väldigt precis temperaturkontroll. Optod uppsättningen presenterad i artikel III innefattaer en volym på 1 liter och organismer upp till en storlek på 50 μm omfattas i den uppmäta syreföbrukningen. Denna metod rekommenderas fö fätmäningar, och anvädes föfätmäningar i Artikel IV. I utvecklingen ingick utformning av en kork fö att montera optod-sensorn i. I artikel I presenteras en utrustning som baseras påen mindre volym (5 ml) vilket innebä att endast mäningar påbakterier och organismer mindre ä 1 μm kan anses tillfölitliga. Detta i kombination med viss variation mellan mäflaskor gö att den framföallt rekomenderas fö anvädning i laboratoriemiljö Det systemet anvädes fö mäningarna av syreföbrukning i laboratorieexperimentet som presenteras i artikel II.
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Tomlinson, Benjamin John. "Modelling Social-Ecological Systems in the Catalan Coastal Zones." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/384929.
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The Systems Approach Framework (SAF) is a methodological framework designed to enhance the efficacy of human decision-making processes within social-ecological systems with regard to sustainability. The SAF was applied in two case studies in the coastal zone of Catalonia, in two separate European Commission Framework Programme projects entitled “Science and Policy Integration for Coastal System Assessment” (SPICOSA) and “Vectors of Change in Oceans and Seas-marine Life, Impact on Economic Sectors" (VECTORS).
During the SPICOSA application, a common issue of interest to most stakeholders was the water quality (harmful bacteria and water clarity) of the local city beaches, particularly following combined sewer overflow events, and mitigating this impact by using stormwater collectors. Water quality influences the beach users’ decision whether to stay at the beach or to leave, thus affecting the revenue received by the bars and restaurants on the beach front. A social-ecological model was constructed using the methodology outlined in the SAF to represent this issue, so that it could be used as a tool for deliberation between the stakeholders. The model output implies that the stormwater collectors have been useful in improving beach water quality in Barcelona, but there will be diminished returns in constructing more. The value of the beach is clearly large in terms of both non-market value and revenues generated in the nearby bars and restaurants. However, the impact changes in water quality would have on the recreational appeal of the beach is estimated to be low and further research is recommended to determine beach users’ sensitivity to beach closures (bacteria limit exceeded) and turbidity.
At the beginning of the VECTORS project, stakeholders who had participated during the previous SAF application expressed a lack of willingness to engage due to a lack of human resources. The scientific team therefore chose to continue the application with the aspiration of demonstrating the SAF model and results at a later date if the stakeholders found the required resources to engage with the process. There is a general perception that jellyfish abundances are increasing along the Catalan coast. Local authorities are concerned about the stranding events and arrivals of jellyfish to beaches and believe it could reduce the recreational appeal of the beaches. Previous studies also demonstrate the predation of jellyfish (Pelagia noctiluca ephyrae) upon some small pelagic fish larvae (Engraulis encrasicolus). Small pelagics are the principal source of revenue for the local fisheries. A social-ecological model was created in order to capture the effects of changes in abundance of Pelagia noctiluca upon the local fisheries, the tourist industry and the wider economy.
Various future scenarios for different abundances of jellyfish blooms were run. Given the changes that these scenarios would cause on the regional gross domestic product and employment, this study concludes that the overall impact of either of these scenarios on the economy would not be significant at the regional scale.
The inclusion of stakeholders in the SAF methodology is rightly fundamental, but in practice, it can be extremely difficult to persuade key stakeholders to participate, and this is a flaw in the SAF which needs addressing. SAF Application model builders are dependent on stakeholders sharing important data or knowledge but this may be withheld for a variety of reasons including, but not limited to, lack of resources to participate, disinterest, and concern about how the results will be used. The SAF is a well-structured methodology for cases where a mathematical model is both relevant and feasible and should be considered as a useful step-by-step guide for managing coastal zone systems towards sustainability.
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Kraaij, Tineke. "Fire regimes in eastern coastal fynbos: drivers, ecology and management." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1008047.
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Conventional knowledge of fynbos fire ecology is based on the summer-autumn fire regimes of the western Cape Floral Kingdom (CFK) where the climate is Mediterranean. However, the climate in the eastern coastal-CFK is milder and rainfall occurs year-round, with presumed effects on fire regimes. The Garden Route National Park (GRNP) has recently been established in the region, in a landscape where indigenous forests, fire-prone fynbos shrublands and fire-sensitive plantations of invasive alien trees are interspersed. The park faces considerable challenges related to the management of fire, including significant pressure from the adjacent plantation industry to reduce wildfire hazard by burning fynbos at short intervals, and high levels of invasion by alien trees (largely Pinus species originating from plantations). This study sought to improve understanding of fire regimes in eastern coastal fynbos shrublands, and to provide guidelines for ecologically sound management of fire in the area. My approach entailed (i) an assessment of the context within which fire management was practiced during the past century; (ii) characterisation of the recent fire history and fire regime (1900–2010); (iii) characterisation of the seasonality of fire weather and lightning; (iv) estimation of minimum fire return intervals (FRIs) from juvenile periods and post-fire recruitment success of overstorey proteoids (non-sprouting, slow-maturing, serotinous Proteaceae); and (v) determination of the ecologically appropriate fire season from post-fire recruitment seasonality of proteoids. I established that historically, plantation protection enjoyed priority over fynbos conservation in the area that is now the GRNP. Fynbos close to plantations has most likely been compromised by frequent and low-intensity burning in the past, as well as by invasion by alien trees. In terms of area burnt (1900–2010), natural (lightning-ignited) fires dominated the fire regime, particularly in the east, whereas prescribed burning was relatively unimportant. Typical fire return intervals (FRIs; 8–26 years; 1980–2010) were comparable to those in other fynbos protected areas and appeared to be shorter in the eastern Tsitsikamma than in the western Outeniqua halves of the study area. Proteaceae juvenile periods (4–9 years) and post-fire recruitment success (following fires in ≥7 year-old vegetation) suggested that for biodiversity conservation purposes, FRIs should be no less than nine years in moist, productive fynbos. Increases in the total area burnt annually (since 1980) were correlated with long-term increases in average fire danger weather, suggesting that fire regime changes may be related to global change. Collectively, findings on the seasonality of actual fires and the seasonality of fire danger weather, lightning, and post-fire proteoid recruitment suggested that fires in eastern coastal fynbos are not limited to any particular season, and for this reason managers do not need to be concerned if fires occur in any season. The ecological requirements for higher fire intensity may nonetheless be constrained by a need for safety. I articulated these findings into ecological thresholds pertaining to the different elements of the fire regime in eastern coastal fynbos, to guide adaptive management of fire in the Garden Route National Park. I also recommended a fire management strategy for the park to address the aforementioned operational considerations within the constraints posed by ecological thresholds. Finally, I highlighted further research and monitoring needs.
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Barnes, Natalie. "The nematode ecology of a UK coastal saline lagoon system." Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402227.
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Preheim, Sarah Pacocha. "Ecology and population structure of vibrionaceae in the coastal ocean." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/58184.
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Thesis (Ph.D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering; and the Woods Hole Oceanographic Institution), 2010.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references.<br>Extensive genetic diversity has been discovered in the microbial world, yet mechanisms that shape and maintain this diversity remain poorly understood. This thesis investigates to what extent populations of the gamma-proteobacterial family, Vibrionaceae, are ecologically specialized by investigating the distribution across a wide range of environmental categories, such as marine invertebrates or particles in the water column. Additionally, it seeks to determine whether in situ population distributions directly result from a competitive advantage over other Vibrio populations. This was investigated by in vitro competition assays on mixtures of native, sterilized particles. Generalist populations were found to dominate the associations with marine invertebrates, consistent with a model of high migration dominated population assembly. A majority of populations occurred broadly within and among the different types of invertebrates sampled, with one population being a near perfect generalist with regard to seasons, host taxa and body regions. High variability across host individuals, consistent with a scenario of stochastic clonal expansion, was especially pronounced in crab and zooplankton samples. Specialization, demonstrated by specific and reproducible association with different particle types in the water column, is more common than specialization within invertebrate hosts.<br>(cont.) Co-existing Vibrio species show strong preferences for different types of particulate matter in the water column suggesting that competition for limited resources influences their evolution. While populations show different growth profiles on particle derived substrates, relative growth advantages of specialist populations in competition with other Vibrio populations on native particles may not be sufficient to explain observed environmental distributions. Instead, populations may gain an advantage on these particles by colonizing the living plant or zooplankton prior to death and degradation into particulate matter. In summary, although vibrios are known commensals of marine invertebrates, evidence suggests that population structure within animals is fairly weak compared to suspended particles in the water column. This highlights the importance of comparing multiple environmental categories and migration among them to investigate population structure and adaptation.<br>by Sarah Pacocha Preheim.<br>Ph.D.
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Gorman, Thomas Andrew. "Ecology of Two Rare Amphibians of the Gulf Coastal Plain." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/26780.
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Globally, amphibian species have been in decline and a wide range of factors have been purported to be driving the decline. The Gulf Coastal Plain of Florida has a high degree of endemism and rarity and the biodiversity in the region includes a diverse suite of amphibian species. Degradation of habitat has been considered by many to be a major part of amphibian declines, however amphibian declines are complex and in many cases multiple factors are occurring in concert. My dissertation research examined aspects of habitat ecology and occupancy for two rare amphibians, Florida Bog Frog (Rana okaloosae) (Chapter 1, 2, and 3) and Reticulated Flatwoods Salamander (Ambystoma bishopi) (Chapter 5), that are both restricted to the Northern Gulf Coastal Plain. Further, for R. okaloosae I examined the influence of a sympatric congener, Bronze Frog (R. clamitans clamitans), on microhabitat selection (Chapter 1) and growth of tadpoles (Chapter 4). My overall goal was to be able to elucidate factors that limit the geographic range of R. okaloosae and A. bishopi and to identify habitat characteristics that managers could maintain or create to conserve or increase populations of these species.
My first chapter examined the microhabitat relationships between R. okaloosae and R. c. clamitans. Rana okaloosae is endemic to northwestern Florida and is sympatric with R. c. clamitans, a more common and widely distributed congener. Further, the two species appeared to be syntopic, have overlapping breeding seasons, and are known to hybridize. The objectives of this chapter were to assess the microhabitat selection of both species and to assess differences in microhabitat use of males of both species during the breeding season. My modeling of habitat selection and comparison of variables used by each species suggests that males of these species select different resources when calling. Therefore, these sympatric ranids select for different resources at a fine scale, however there does appear to be some overlap among some selected habitat characteristics.
In Chapter 2, I assessed the habitat use of R. okaloosae at multiple spatial scales. I surveyed for R. okaloosae and evaluated habitat characteristics at used sites and sites where I had no detections to develop among- and within-stream habitat models for R. okaloosae. Rana okaloosae used habitats with high amounts of emergent vegetation at both the among-stream scale and the within-stream scale. Emergent vegetation appears frequently in models of anuran habitat selection, particularly those that occur in fire-dominated landscapes. Further understanding the habitat requirements of R. okaloosae will allow land managers to use appropriate management activities (e.g., prescribed fire) that will increase emergent vegetation and potentially restore habitat that may help increase populations of R. okaloosae.
In Chapter 3, I conducted aural surveys for R. okaloosae at two different spatial scales: range-wide and stream-level scales to understand how occupancy and colonization of R. okaloosae may be influenced by scale. My results suggest that at both spatial scales occupancy of R. okaloosae was best described by the presence of mixed forest wetlands at survey sites. At the range-wide scale, colonization and detection were constant across years, however, at the stream-level scale, colonization was predicted by the number of years since last fire and detection was best predicted by the additive combination of relative humidity and temperature. Occupancy of R. okaloosae was patchy at the range-wide and at the stream-level scales and colonization was low at both scales, while derived estimates of local extinction were moderately high. While R. okaloosae still occur in 3 watersheds where they were initially observed in the 1980â s, one of the three watersheds appears to be very isolated and detections there are becoming very infrequent.
In Chapter 4, I experimentally evaluated the effects of R. c. clamitans tadpoles on R. okaloosae tadpoles. My results suggest that there was limited influence of R. c. clamitans on R. okaloosae. Conversely, it appeared that Rana c. clamitans was more susceptible to intraspecific competition than interspecific competition. The lack of a strong competitive effect of Rana c. clamitans on Rana okaloosae suggests that competitive interactions among tadpoles may have a limited effect at the densities I examined.
In Chapter 5, our objectives were to evaluate a suite of within-pool factors (i.e., vegetation structure, water level, and an index to presence of fish) that could influence occupancy of breeding wetlands by larval flatwoods salamanders on Eglin Air Force Base in Florida, USA. Site occupancy over a 4 year period was best described by a model that incorporated high herbaceous vegetation cover and open canopy cover. Detection probability was assessed, but it varied among years and was not included in the model. Our study suggests that managing the breeding habitat of flatwoods salamander for open canopies and dense herbaceous vegetation may contribute to this speciesâ recovery.
In conclusion, Chapters 1-3 of my dissertation contribute to a growing understanding about the habitat ecology of R. okaloosae. I have evaluated habitat use of R. okaloosae at multiple spatial scales. At the finest spatial scale R. okaloosae selected for sites that had an abundance of cover probably decreasing their risk of predation (Chapter 1). Similarly, in Chapter 2 at two spatial scales, among and within-streams, R. okaloosae selected for emergent vegetation. Finally, at the broadest spatial scale, range-wide, R. okaloosae were found to be associated with mixed forest wetlands (Chapter 3). I did not find strong support for competition between R. okaloosae and R. c. clamitans tadpoles, although there was some evidence of asymmetric competition (Chapter 4). Further, adult males of each species did not select the same habitat characteristics for calling sites, so there appeared to be some resource partitioning (Chapter 1). Finally, the presence of A. bishopi larvae was found to be associated with herbaceous vegetation and moderate amounts of canopy cover (Chapter 5). Results from Chapter 2 and 5 suggest that both R. okaloosae and A. bishopi are associated with habitat conditions that are likely a result of fire penetrating wetland areas.<br>Ph. D.
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Baum, Kristen Anne. "Feral Africanized honey bee ecology in a coastal prairie landscape." Texas A&M University, 2003. http://hdl.handle.net/1969/150.
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Wimble, G. T. "The palaeoecology of the lowland coastal raised mires of South Cumbria." Thesis, Bucks New University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374830.
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Nicholas, Kirsty Rebecca. "Secondary production of coastal plankton communities in the western Irish Sea." Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307669.
Full textAbstract:
The effect of hydrography onthe planktonic community structure and secondary production of an area offthewest coast of the Isle ofMan was investigated in 1993. This region is subject to stratification in summer (May to September), the boundary between mixed and stratified water masses being marked bytheManx West Coast front (MWC). Acoastal front was also occasionally present, separating the mixed water mass from coastal water. Large interannual variability inthe strength of the stratification was apparent between 1993 and 1994. There were large seasonal changes in nutrient concentrations, with maximal concentrations inthe winter months. Nutrient depletion of theupper layer of thewater column in summer was apparent. Phytoplankton spatial distribution was strongly related to the physical structure of the area and higher fluorescence was measured during thegreater stratification in 1994. Abundances were initially highest inthe surface layers of the water column, though inlate summer were highest at the thermocline. Thetiming of the spring bloom was variable. Aseasonal succession of phytoplankton species was observed. The winter phytoplankton assemblage was dominated bylarge benthic and chain diatoms and the summer assemblage byRhizosolenia species. Agreater number of dinoflagellates were present inthe stratified area. The zooplankton assemblage was dominated bythe copepod species Pseudocalanus elongatus, Acartia clausi, Temora longicomis and Oithona simtlts, peak abundances occurring inJuly. No spatial variation was evident inzooplankton densities and composition except for ichthyoplankton densities, which were greater inshore. No spatial differences were noted incopepod grazing rates, eggproduction rates or chemical composition. However, seasonal and interspecific differences were considerable, with ingestion rates highest during the spring bloom and grazing impact greatest during the summer. Copepods grazed only a small proportion of the chlorophyll a inthe water column. Maximum rates of egg production occurred in April, prior to the spring phytoplankton bloom, butwere also high in the summer. Interspecific differences inthe numbers of eggs produced bycopepods and intheir seasonal production patterns were large. Only a small portion of the populations were producing eggs at anyonetime. This individual variability was attributed to the age structure of the population. Copepods were consuming enough algae to cover the energetic costs of reproduction. A. clausi and T. longicornis had the highest rates of grazing and egg production. T. longtcomis actually had the greatest impact onthe ecosystem, despite being far less abundant than the other copepod species. High mortality inthejuvenile stages was hypothesised as the reason for its low adult abundances. Protein was the major chemical constituent of the zooplankton, then lipids with carbohydrates only forming a small percentage of the dry weight. The amount of each of these components peaked inthe summer, their relative percentage varying seasonally. The stratified site, being the deepest, had the highest standing stocks of plankton. It was calculated that copepod stocks and productivity were generally high enough to support the observed densities of ichthyoplankton in the region.
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Turner, Stephanie Jane. "The ecology of hard-substratum epifaunal assemblages : effects of larval recruitment, competition and grazing." Thesis, University of St Andrews, 1989. http://hdl.handle.net/10023/13951.
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Artificial substrata were employed at sites on the east and west coasts of Scotland, in such a manner as to model the habitat found on the undersides of boulders on the shore. Panel treatments were devised to examine the effects of substratum 'age' and larval availability, and the presence or absence of varying densities of herbivorous molluscan grazers on the development of the epifaunal assemblages. The importance of inter- and intraspecific competition in structuring the bryozoan component of the assemblage was also examined. A necessary pre-requisite for the settlement of many marine invertebrate larvae may be the development of a microfouling film, the nature of which may vary depending on its 'age', with corresponding effects on the 'attractiveness', or otherwise, to potentially settling larvae. The lowest numbers of recruits were frequently recorded on the 'youngest' panels, and greater numbers generally occurred on panels immersed for longer periods. Also of overriding significance, however, was the seasonal variability in larval availability. The assemblages were characterized by high levels of post-settlement mortality. The outcomes of the overgrowth interactions between 18 species of encrusting bryozoans were highly variable and complex, each species of an interacting pair won some encounters, and neither consistently overgrew the other. Therefore, the pattern of competitive abilities was neither entirely intransitive or transitive. Variations in outcome were found to be at least partially attributable to differences in the encounter angle between colonies. The competitive ability of a species also varied among sites and between years. The herbivorous grazing gastropod Gibbula cineraria was found to have a markedly deleterious effect on the developing assemblages. Furthermore, individuals and colonies of the epifaunal species were apparently unable to achieve an 'escape-in-size' under the experimental conditions employed.
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Arimitsu, Mayumi. "The influence of glaciers on coastal marine ecosystems in the Gulf of Alaska." Thesis, University of Alaska Fairbanks, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10146002.
Full textAbstract:
<p> Glacier runoff (i.e., meltwater and rainwater discharged at the glacier terminus) provides about half of the freshwater discharge into coastal margins of the Gulf of Alaska, where contemporary glacier melting rates are among the highest in the world. Roughly 410 billion metric tons of glacier runoff enter the Gulf of Alaska each year. With freshwater discharge volumes of that magnitude, I hypothesized that glacier runoff has both direct and indirect effects on the receiving coastal marine ecosystems that support rich food webs, abundant and diverse marine communities, commercial fisheries and tourism industries. To examine the influence of glacier runoff on coastal marine ecosystems, I focused on three questions: 1) How does the marine food web respond to physical and biological gradients induced by glacier runoff? 2) What is the contribution of riverine organic matter (OM) and ancient carbon resources in glacier runoff to marine food webs from plankton to seabirds? and 3) How does the influence of glaciers on coastal marine ecosystems differ at small to large spatial and temporal scales? I measured physical, chemical and biological indices within four fjord systems along the eastern Gulf of Alaska coast. In chapter one I used geostatistics as well as parametric and non-parametric models to demonstrate a strong influence of glacier runoff on ocean conditions and coastal food webs across all the fjord systems. In chapter two I used isotopes (δ<sup> 2</sup>H, δ<sup>13</sup>C, δ<sup>15</sup>N, and δ<sup> 14</sup>C) to trace riverine OM and ancient carbon resources into the marine food web. This work included the development of a novel multi-trophic level 3-isotope Bayesian mixing model to estimate the proportion of allochthonous resources in animal tissues. Mean estimates from 14 species groups spanning copepods to seabirds ranged from 12–45 % riverine OM source assimilation in coastal fjords, but ancient carbon use by marine food webs was low. In the third chapter I synthesized information on the scale-dependent influence of glaciers on lower-trophic level productivity, predator-prey interactions and ways that humans may be affected by anticipated changes in glacier coverage. This contemporary understanding of glacier influence on coastal ecosystems aligns with paleoenvironmental evidence suggesting that over geological time scales glaciers have and will continue to shape marine ecosystems in the Gulf of Alaska.</p>
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Ness, Kirsten L. "The Effects of Shoreline Development on Lake Littoral and Riparian Habitats: Are Shoreline Protection Regulations Enough?" Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/NessKL2006.pdf.
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Notman, Gillian Margaret. "A comparison of the trophic ecology of grazing gastropods on the rocky shores of northern and southern Britain." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=182328.
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Intertidal grazing gastropods play an important role in structuring rocky shore communities. For many years the main food resource to these animals was considered to be epilithic biofilms. This study shows that macroalgae are a more important component of gastropod diets than was previously appreciated and that biofilms contribute surprisingly little to their trophic ecology. Stable carbon and nitrogen isotope analyses were used to examine grazer diets, comparing sources of assimilated carbon and nitrogen in gastropod tissues between moderately wave exposed and sheltered sites in northern and southern Britain. Carbon isotope (δ13C) values of biofilms were considerably lower than those of grazing gastropods at all of the sites examined. The δ13C values of grazer tissues were much more closely related to the carbon isotope values of macroalgae, demonstrating the importance of these foods to intertidal grazing gastropods. Nitrogen isotope values were consistent with this conclusion and reflected differences in the source pools of nitrogen between the two sampling regions. Gut contents analysis was used to directly quantify the diet of the intertidal limpet Patella vulgata in detail. Biofilms and corticated/leathery macroalgae contributed most substantially to patterns of ingested materials and limpet diet was strongly influenced by food availability. Animals from sheltered and northern sites consumed more macroalgae whilst animals from southern sites consumed more biofilm. Stable isotope data from mensurative experiments confirmed the important role of food availability in controlling limpet diets. Data from manipulative caging experiments provided further evidence for this effect and also showed that species identity and interspecific competition influence trophic ecology in intertidal gastropods. Patella depressa isotope values remained different from those of Patella vulgata irrespective of food availability and competition in experimental cages. Stable isotope ratios of Patella vulgata and Littorina littorea, distinct in single species cages, converged towards a common value when held together.
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Chen, Bingzhang. "Trophic interactions within the microbial food web in Hong Kong coastal waters and the South China Sea /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?AMCE%202008%20CHEN.
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Mucciolo, Serena. "Polychaete fauna of the Northwest Portuguese Coastal Shelf: ecology, diversity and distribution." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9640/.
Full textAbstract:
Polychaetes are one of the larger groups of macroinvertebrates with more than 9000 species recognised, distributed worldwide. Thanks to the broad ecological adaptability and high abundaces, this taxon plays a leading role and is considered an important component of all benthic assemblages.
Our knowledge about the West Iberian Coast polychaete fauna are scarce, and the only studies are recent. In this sense, the aim of this work was to investigate the composition and the spatial distribution of the polychaete fauna along the NW Portuguese Coastal Shelf, focusing on their relationship to environmental factors (depth, grain size, longitude and latitude) and to add new data to the existing biological dataset. A total of 39 sites were analysed, collected in an area of about 5665 km², between 20 and 150 m depth, distributed in a way to cover the overall grain size gradient.
A total of 9352 specimens belonging to 41 families were found, and the analysis based on the abundance of polychaete species revealed five affinity groups: (a) nearshore medium sand characterised by Pisione parapari and Hesionura elongata; (b) very coarse sand that showed the highest abundance of Syllidae and was characterised by Protodorvillea kefersteini and Syllis garciai; (c) fine sand dominated by Spiophanes bombyx and Glycera tridactyla; (d) very fine sand with Nepthys assimilis and Amage sp. and the highest abundance of Paraonidae; (d) mud characterised by Labioleanira yhleni and Ampharete finmarchica. The combination of the environmental variables and the biological data, done with BIOENV routine, demonstrated that depth, grain size and fine contents were the best related with the biological data (rho=0.598). In general, the results agree with the composition and the spatial distribution of the polychaete fauna in other parts of the world; further polychaete assemblages related to mud sediments were firstly recorded in the Northwestern Portuguese Coastal Shelf.
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Nowell, Megan Sarah. "The application of landscape ecology techniques for managing disturbed Mediterranean coastal seascapes." Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/283581.
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La presión antropogénica es la amenaza preeminente para la biodiversidad, la resiliencia y el funcionamiento ecológico de los medios costero y marino. El desarrollo de respuestas efectivas a esta amenaza multifacética es un desafío importante para los gestores y responsables de la toma de decisiones, debido a la complejidad de los ecosistemas marinos poco conocidos. La interpretación ecológica fidedigna de los datos espaciales utilizando técnicas de ecología del paisaje marino tiene el potencial de ser una poderosa herramienta de gestión. Esta disciplina emergente explora las causas y consecuencias de los patrones espaciales en el medio marino. En esta tesis, las técnicas de ecología del paisaje marino se utilizan para entender las consecuencias ecológicas de las perturbaciones antropogénicas sobre los patrones espaciales de los paisajes marinos mediterráneos costeros a través de tres estudios.
En el primer estudio se exploró la relación entre los patrones espaciales y la biodiversidad. La cuantificación de la estructura del paisaje marino mediante una métrica de patrones espaciales mostró que la riqueza de las especies se puede conservar mediante la protección de la diversidad de hábitats en el paisaje marino. Los resultados también pusieron de relieve la importancia de la de la complejidad en la distribución en cuanto a la riqueza de especies. Se determinaron los efectos de las presiones antropogénicas sobre la estructura del paisaje marino utilizando las métricas espaciales y el análisis multivariante.
Este enfoque permitió evaluar la influencia de las diferentes variables de perturbación sobre los componentes específicos del paisaje marino. Los resultados indican que la contaminación de origen terrestre está provocando la fragmentación del paisaje marino y tiene la mayor influencia en la composición del mosaico de hábitats. En el último estudio , se determinó el efecto de estas perturbaciones en los servicios que proporcionan los ecosistemas utilizando los stocks de carbono como indicadores, en particular en las praderas de fanerógamas. En análisis mostró la importancia del hábitat en el paisaje marino en cuanto a los servicios de los ecosistemas.
Concluimos que las técnicas de cuantificación del paisaje marino proporcionan información valiosa sobre las causas y consecuencias de los patrones espaciales de los ambientes mediterráneos costeros. La cuantificación de la estructura del paisaje marino con métricas de patrones espaciales es una técnica efectiva y consistente para la evaluación ecológica fidedigna de los datos espaciales a las escalas necesarias para la gestión. Los enfoques presentados en esta tesis son herramientas e instrumentos informativos valiosos para los planes de conservación.<br>Anthropogenic pressure is the preeminent threat to the biodiversity, resilience and the ecological functioning of the coastal and marine environment. Developing effective responses to this multifaceted threat is a significant challenge for managers and decision-makers due to the complexities of poorly understood marine ecosystems. The ecologically meaningful interpretation of spatial data using seascape ecology techniques has the potential to be a powerful conservation tool. The emerging discipline of seascape ecology explores the causes and consequences of spatial patterns in the marine environment. In this dissertation, seascape ecology techniques are used to understand the ecological consequences of anthropogenic disturbance on the spatial patterns of coastal Mediterranean seascapes through three studies.
In the first study, the relationship between spatial patterns and biodiversity was explored. Quantification of seascape structure using spatial pattern metrics showed that species richness can be conserved by protecting the diversity of habitats in the seascape. The results also highlighted the importance of patch complexity for increased species richness. Using spatial metrics and multivariate analysis, the effects of anthropogenic pressures on seascape structure was determined. This approach allowed for the influence of different disturbance variables on specific components of the seascape to be assessed. The results indicate that land-based pollution is causing fragmentation of the seascape and has the largest influence on the composition of the mosaic of habitats. In the final study, the effect of these disturbance variables on ecosystem service delivery was determined using carbon stocks as an indicator ecosystem service. Land-based pollution emerged as an important driver of seascape structure and seagrass carbon capture. The analysis emphasized the importance of habitat context within the seascape for ecosystem service delivery.
We conclude that seascape quantification techniques provide valuable information on the causes and consequences of spatial patterns in coastal Mediterranean seascapes. Quantifying seascape structure using spatial pattern metrics is an effective and consistent technique for the ecologically meaningful evaluation of spatial data at the scales required for management. The approaches presented in this dissertation are valuable and informative tools for conservation planning.
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Noel, Brandon Lennon. "The winter ecology of the piping plover (Charadrius melodus) in coastal Georgia." Connect to this title online (Georgia Southern site) Connect to this title online (U.S. Fish & Wildlife Service site), 2006. http://www.fws.gov/nc-es/birds/Noel_2006_MSThesis.pdf.
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Quaggiotto, Maria Martina. "The role of marine mammal carrion in the ecology of coastal systems." Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/7099/.
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Carrion represents an important energy resource in the natural world, yet its ecological significance has often been overlooked. It also plays a crucial role facilitating energy transfer across trophic levels and between ecosystems. The aim of this thesis was to evaluate the role of marine mammal carrion in the ecology of coastal systems, investigating one of the most commonly occurring sources of marine mammal carrion in the UK, the grey seal (Halichoerus grypus). This was addressed by providing first a detailed documentation of the fate of a grey seal pup carcass with insights on the scavenging ecology existing in both terrestrial and marine ecosystems. On the shore, great black-backed gulls (Larus marinus), juvenile gulls and ravens (Corvus corax) fed on the carcass showing a distinct temporal succession using the food resource. The underwater carcass was initially dominated by Echinodermata (starfish), whose abundance dropped lately, while Malacostraca (crabs) were present in similar number during the whole monitoring. Bacterial activity was evident in both experiments. Predictability of seal carrion was then defined during the pupping season at one of the largest colonies in the UK, the Isle of May (Scotland). Data collected by aerial survey (11 years) and ground visual census (3 years) were used to estimate the inter-annual variability of carrion, from placentae and dead seals, according to its timing, biomass and energy released and spatial distribution on the island. For all measures considered, variability was below 34%, similarly to other resources, such as salmon runs, which appear to be predicted by consumers. Twenty one percent of the total biomass from dead seals was consumed at the end of the pupping season suggesting a clear response from the scavenging community to the presence of the resource carrion. The predictable nature of seal carrion was then tested exploring the spatial and temporal distribution of scavenging gulls at three geographical scales (regional, local and patch scales). The great black-backed gull was affected by carrion availability occurring on the Isle of May, while the herring gull (Larus argentatus) was not. In particular, the number of adult and juvenile great black-backed gulls feeding was directly correlated with carrion abundance, while searching behaviour was greatest after the mean seal pupping date and at the peak in mortality. The behavioural dynamics of scavengers were finally explored monitoring the feeding activity on pup carcasses and placentae of adult and juvenile great black-backed gulls. It was predicted that under conditions of predictable and abundant carrion an equal scavenging effort would be found for the two age classes when consuming carcasses. Hierarchical dominance was, instead, expected during scavenging activity on placenta as it represents a preferred energy-rich food item. Temporal trends of scavenging activity and time spent feeding on carcasses were in fact similar between the two, while young individuals spent more time feeding on placenta, highlighting the importance of this food source for juvenile gulls during winter. The house mouse was also found to scavenge on seal carrion, which until now has been undocumented. This study demonstrates the importance of marine mammal carrion as a resource for multiple facultative scavenger species in both the marine and terrestrial environment.
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Williams, Sally Jayne. "Wave-seabed interaction in a stratified coastal environment." Thesis, The University of Sydney, 2010. https://hdl.handle.net/2123/28910.
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The attenuation of non—breaking waves in shallow waters can be dominated by soft seabed
effects as opposed to water viscosity. Due to the complexity of natural systems, rheological
approaches can provide useful parameter constraints on natural behaviours.
In part I of this thesis a layered rheological model of the seabed is adopted. The upper part
of the seabed is considered to be in a state of dynamic liquefaction, whilst the lower portion
of the bed is more consolidated. It is demonstrated that in the absence of wave-induced
turbulence the magnitude of the surface wave damping due to the presence of the porous
bed is greater than that due to shear at the interface between the two fluids. For the case
of a shallow layer of fluidised bed material, it is shown that the maximum damping effect of
the porous elastic bed coincides with the maximum damping rates due to boundary layer
shear effects, thus accentuating wave damping when the dimensionless lower layer depth is
approximately 30—50% greater than the non—dimensionalised boundary—layer thickness.
In part II of this thesis a model for the interaction between interfacial waves with the
seabed is considered. A new wave dispersion equation is derived for waves on a two-layer
stratification above a porous seabed including free surface effects. Numerical results indicate
that the wavelength and wave amplitude are attenuated faster by a coarse seabed material
as opposed to a fine sandy bed. It is shown that the profile of an interfacial wave exhibits
properties similar to that of an interfacial wave propagating above a rigid bed and agrees
qualitatively with observations of interfacial waves in littoral waters. The effect of a porous
elastic bed is to increase the wave steepness, causing a narrower crest and a Wider trough.
Comparison of the numerical results with experimental results on the different mechanisms
for interfacial wave decay show that, in water of intermediate depth, the energy attenuation
caused by a coarse—grained sandy seabed is greater than that due to bottom boundary layer
damping, interfacial wave shear or interior Viscous damping.
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McLain, Nathan K. "Effects of sea level rise on decomposers in a restored coastal salt marsh." Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1595237.
Full textAbstract:
<p> Many southern California coastal salt marshes are urbanized and heavily impacted, but still provide important ecosystem services, including carbon and nutrient cycling. Salt marsh community structure and functions, such as decomposition, are essential for marsh ecosystems and are potentially vulnerable to inundation impacts created by sea level rise (SLR). The saltmarsh communities driving decomposition are comprised of invertebrates, fungi, and bacteria, which may be susceptible to SLR. In this project, inundation of saltmarsh sediments with associated plants and rhizosphere were manipulated using a marsh organ to assess the impacts of SLR on decomposer activity (leaf litter decay, anaerobic respiration) and community structure (bacterial and benthic invertebrate). Marsh organ samples across all inundation treatments showed altered decomposer community diversity and function compared to controls, indicating disturbance. However in some cases there were no significant differences between communities among SLR treatments. However, inundation effects may have been obscured by marsh organ artifacts.</p>
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Jaal, Zairi Bin. "Studies on the ecology of the coastal anopheline mosquitoes of Northwestern Peninsular Malaysia." Thesis, University of Liverpool, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306498.
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Schulte, Nicholas O. "Controls on Benthic Microbial Community Structure and Assembly in a Karstic Coastal Wetland." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2447.
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The assembly mechanisms underlying microbial community abundance, biotic interactions, and diversity over space and time are unresolved, particularly in benthic microbial mats distributed along environmental gradients. Experimental enrichment of nutrient-limited microbial mats from the Florida Everglades along a nutrient subsidy-salinity stress gradient stimulated autotrophic and heterotrophic metabolism, growth, and diversity independent of autotroph-heterotroph interactions across treatments and space. These results suggest spatial segregation of autotrophic and heterotrophic components within mats. Considering only the diatom component of Everglades mats over space and time, the subsidy-stress gradient controlled diatom compositional turnover at broad spatial scales while environmental and dispersal-based processes structured diatom communities at the regional scale and environmental processes independent of the environmental gradient at the temporal scale. These results indicate environmental gradients may not necessarily increase connectivity and dispersal across space, and temporal microbial diversity is driven at the local and regional scales by environmental heterogeneity in benthic microbial communities.
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Breeden, Charles F. "A multitemporal analysis of Georgia's coastal vegetation, 1990-2005." unrestricted, 2008. http://etd.gsu.edu/theses/available/etd-04172008-133241/.
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Thesis (M.A.)--Georgia State University, 2008.<br>Title from file title page. Jeremy Diem, committee chair; Jeremy Crampton, John Allensworth, committee members. Electronic text (126 p. : col. maps) : digital, PDF file. Description based on contents viewed July 17, 2008. Includes bibliographical references (p. 110-121).
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Jirinec, Vitek. "Habitat use of the Declining Wood Thrush in Coastal Virginia." W&M ScholarWorks, 2015. https://scholarworks.wm.edu/etd/1539626794.
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Kyryliuk, Dmytro. "Total suspended matter derived from MERIS data as an indicator of coastal processes in the Baltic Sea." Thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-137165.
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Samuels, A. J. "The influence of water quality on the aquatic habitats of a coastal grazing marsh." Thesis, University of Essex, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333475.
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Iriarte, Arantza. "Picophytoplankton : ecological and physiological studies in culture and in natural coastal and estuarine waters." Thesis, University of Southampton, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358363.
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Schulz, Jessica L. "Factors Affecting Prey Availability and Habitat Usage of Wintering Piping Plovers (Charadrius melodus) in Coastal Louisiana." Thesis, University of Louisiana at Lafayette, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10002450.
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<p> The Gulf of Mexico is home to a large proportion of the wintering population of the threatened piping plover, but little is known about the bird’s ecology in this region. In Louisiana, the majority of wintering piping plovers are found on the state’s rapidly eroding barrier islands. Between August 2013 and May 2014, we conducted shorebird surveys to assess the abundance and habitat use patterns of piping plovers on a barrier island refuge in south central Louisiana. Seventy-five percent of piping plovers observed were foraging, mostly (92%) in the intertidal zone; 20% were roosting in more diverse microhabitats. To characterize the prey base for piping plovers on the islands, we collected core samples in the intertidal zone of two islands on the refuge. The invertebrate community was dominated by haustoriid amphipods, which comprised 87.5% of individuals collected. Bivalves and polychaetes accounted for 9.3%, and 2.7%, respectively. We used generalized linear models to evaluate the effects of environmental predictors on amphipod abundance and odds of bivalve and polychaete presence at the sample site scale, and also on piping plover densities at the transect scale. Moisture had a positive effect on amphipod abundance and polychaete presence. Seasonal patterns and between-island differences were observed in all three taxa, but these effects differed between main beach habitat and the gulf- and bay-sides of prominent sand spits. Amphipod densities and piping plover densities were correlated on Trinity Island and during spring 2014, but prey abundance did not differ between sample sites where piping plovers were foraging versus random sites. Uncertainty in the degree to which piping plover distributions in Louisiana are driven by prey abundance is of concern because the extensive beach nourishment programs being implemented to stave off coastal land loss may have potentially substantial impacts to benthic invertebrates and their predators.</p>
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Regan, Matthew. "Plant community response to wetland enhancement techniques in coastal wetlands of the upper St. Lawrence River." Thesis, State University of New York Col. of Environmental Science & Forestry, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10254553.
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<p> Stabilized water levels of the upper St. Lawrence River have reduced plant diversity and allowed competitively dominant taxa such as <i>Typha </i> x <i>glauca</i> and <i>Typha angustifolia </i> to displace productive sedge meadow habitat. This research studied the effects of two wetland enhancement techniques using habitat heterogeneity and manipulating hydrology. Dredge spoils from pothole excavations in <i> Typha</i> marshes were reconfigured to create habitat mounds. These habitat mounds created from an exposed seed bank had less <i>Typha</i> spp. and were more diverse than the surrounding remnant <i>Typha</i> marshes. Sedge meadow vegetation did not successfully colonize these habitat mounds. Water levels at two wetlands were raised above the water levels of the upper St. Lawrence River. Raising water levels increased floating leaf aquatic vegetation but did not decrease <i>Typha</i> spp. Alternative enhancement methods may be necessary to control <i>Typha</i> spp. while restoring sedge meadows.</p>
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Sundblad, Göran. "Spatial Modelling of Coastal Fish – Methods and Applications." Doctoral thesis, Uppsala universitet, Limnologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-132620.
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Environmental factors influence species and habitats on multiple scales creating a mosaic of distribution patterns. Studying factors shaping these patterns are central to our understanding of population dynamics and ultimately ecosystem functioning. Information on the distribution of resources and conservation values are also highly needed in marine management as coastal areas are increasingly influenced by human activities. In this thesis, large-scale field data is used to explore how strong environmental gradients found on multiple scales in the coastal areas of the Baltic Sea influence fish habitats. The underlying concepts are based in the field of species distribution modelling, whereby habitat maps can be produced using environmental layers in a geographic information system. Distribution modelling is further used to address both ecological and applied questions by examining effects of habitat limitation on fish population sizes and to evaluate management actions aimed at habitat conservation. I show that specific habitat requirements for fish species of both freshwater and marine origin can be described using environmental variables and that species-environment relationships can be used to predict the distribution of early life-stages of fish in the Baltic Sea archipelagos. Further, predicted habitat availability of a specific life-stage was directly related to adult population size of Eurasian perch Perca fluviatilis, signifying that the abundance of large predatory fish can be limited by specific recruitment habitats. Lastly, by predicting the distribution of an assemblage of coastal fish species and their associated habitats, an assessment of a network of marine protected areas was performed. Results revealed large gaps in the current network and identified areas suitable for future protection. By demonstrating how current habitat protection can be improved by including critical habitats for coastal fish population sizes this thesis points to the benefits of integrating nature conservation and fisheries management. Based on these findings I conclude that species distribution modelling provides a suitable analytical framework for assessing the habitat requirements of organisms. An increased understanding of habitat-population relationships and an ability to accurately map ecologically important features will be of great value for an ecosystem-based marine management. <br>Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 709
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Fulweiler, Robinson Walter. "The impact of climate change on benthic-pelagic coupling and the biogeochemical cycling of Narragansett Bay, R.I./." View online ; access limited to URI, 2007. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3276984.
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Griffiths, Megan Elizabeth. "Salt spray effects on rare New England coastal sandplain heathland plant communities /." Thesis, Connect to Dissertations & Theses @ Tufts University, 2003.
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Thesis (Ph.D.)--Tufts University, 2003.<br>Adviser: Colin M. Orians. Submitted to the Dept. of Biology. Includes bibliographical references (leaves 181-200). Access restricted to members of the Tufts University community. Also available via the World Wide Web;
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Moore, Travis Allan. "Trophic Dynamics and Feeding Ecology of the Southeast Florida Coastal Pelagic Fish Community." NSUWorks, 2014. http://nsuworks.nova.edu/occ_stuetd/3.
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The combined methods of stomach content analysis and stable 15N and 13C isotope biochemistry analysis were used to investigate the trophic dynamics and feeding ecology of coastal pelagic fishes in the waters off southeastern Florida, USA. The coastal pelagic fish complex includes blackfin tuna Thunnus atlanticus, dolphinfish Coryphaena hippurus, king mackerel Scomberomorus cavalla, little tunny Euthynnus alletteratus, skipjack tuna Katsuwonus pelamis, and wahoo Acanthocybium solandri. These coastal teleosts, particularly the tunas and wahoo, are primarily targeted by recreational anglers. However, there is a shortage of available trophic and diet composition data concerning these fishes of the coastal pelagic ecosystem. Stomach and muscle tissue samples were collected from the species of various lengths over a three-year period from March 2010 and March 2013. Across all six species, teleost fishes dominated the prey with an average 64.5% by occurrence, 63.7% by number, and 89.9% by weight. There were two dominant prey families: Clupeidae and Carangidae. Dolphinfish showed the lowest diet overlap among the six species, due to the highly diverse diet. The highest diet overlap occurred between king mackerel and little tunny. The mean δ15N ranged from 8.21 ‰ (wahoo) to 13.18 ‰ (king mackerel), and the mean δ13C ranged from -18.41 ‰ (king mackerel) to -16.70 ‰ (dolphinfish). Blackfin tuna exhibited the largest δ15N range (7.22 to 13.21 ‰), as well as the largest δ13C range (-19.13 to -12.99 ‰). The δ15N and δ13C signatures in the muscle tissue showed evidence of shifts to higher trophic levels with an increase in fish size and the formation of distinct trophic groups among the coastal pelagic predators. The δ13C also suggested an inshore-offshore spatial relationship among the coastal pelagic fish. The trophic dynamics and feeding ecology data generated by this study will provide valuable baseline data for the coastal pelagic complex and future ecosystem studies.
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Andrew, Deborah. "Ecology of the tiger quoll dasyurus maculatus maculatus in coastal New South Wales." Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20070501.155009/index.html.
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Martin, Ainsley. "The ecology and palaeoecology of the charophyte Lamprothamnium papulosum in U.K. coastal lagoons." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271668.
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