Dissertationen: „Coastal biology“

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Nilsen, Liv Sigrid. „Coastal heath vegetation in central Norway; recent past, present state and future possibilities“. Doctoral thesis, Norwegian University of Science and Technology, Department of Biology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-250.

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Jolley, Elizabeth Charlotte. „The role of coastal defence structures in channeling production in coastal ecosystems“. Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/63289/.

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This study assessed the interaction of coastal defence structures (CDSs), namely shore-parallel ‘low crested breakwater structures’ (LCSs), design features and hydrodynamic regime on the quantity and timings of macroalgae deposition. The employed sampling strategy comprised a spatially and temporally stratitified approach of time-lapse photography of macroalgae deposition, verified with field observations. Field surveys determined the associated ecological assemblages of the sediment infauna and rocky shore epifauna associated with the breakwater scheme, as well as for two nearby beaches with groynes. Further analysis determined decay rates, decay processes, changes in C and N stable isotope values of dominant macroalgal species and the dependence of the faunal assemblages on the decaying macroalgae deposits. Temporal analysis highlights the main factors driving macroalgal deposition were differences in spring and neap tidal range, wave height and sea temperature. Greatest deposition occurred during months of lower wave height and fewer storms, when filamentous red algae and ephemeral green algal species dominated. Results indicated to greater amounts of macroalgae deposits around LCSs than around wooden or granite groynes. Beach elevation best explained the spatial variation, both vertically and horizontally, in the benthic assemblages within the breakwater scheme, with the abundance of detritivorous deposit feeders being significantly correlated with abundance of macroalgae deposits. Orientation of LCSs, relative to wave action, was an important driver of epifaunal assemblages on the CDSs, with the eastward ends of the breakwaters providing the optimum intermediate environment with regards to wave action, exhibiting the greatest abundances of epifauna. Stable isotope analysis showed that the carbon and nitrogen isotopic values of macroalgae changed during the decomposition and were both species and time dependent. Isotope analysis illustrated that decaying macroalgae deposits were of greater trophic importance to species within the LCS ecosystem where there was large macroalgal deposition, than to species within the groyne ecosystem where macroalgal deposition was lower. Key findings of the study illustrate the importance of decaying macroalgae deposits for the local ecosystem via modification of food chain energy flows. Though the ecosystem benefits from this allochthonous resource, deposits may be a nuisance requiring controlled human intervention.

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Fitzgerald, Megan. „The relationship between biodiversity and ecosystem function in a coastal wetland“. Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1572435.

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Despite reductions in species diversity, few studies in wetlands investigate the relationship between biodiversity and ecosystem function (BEF). My research explores the BEF relationship in a recently restored salt marsh in Long Beach, California. I hypothesized that: (1) increasing plant diversity would result in higher primary productivity and decreased recruitment of native salt marsh plants, (2) observed variation in responses would be correlated with species-specific variation in individual demographic parameters, and (3) variation in demographic parameters and resulting ecosystem processes would be correlated with functional traits. I found that while survival over one year was correlated with elevation, overall percent cover and recruit species richness were positively affected by diversity. Performance patterns reveal variation by species in photosynthetic rate, leaf mass per area and chlorophyll a/b ratios. After one year, I found that the overall diversity patterns were driven by selection effect compared to complementarity.

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Wilson, Benjamin J. „Drivers and Mechanisms of Peat Collapse in Coastal Wetlands“. FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3718.

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Coastal wetlands store immense amounts of carbon (C) in vegetation and sediments, but this store of C is under threat from climate change. Accelerated sea level rise (SLR), which leads to saltwater intrusion, and more frequent periods of droughts will both impact biogeochemical cycling in wetlands. Coastal peat marshes are especially susceptible to saltwater intrusion and changes in water depth, but little is known about how exposure to salinity affects organic matter accumulation and peat stability. I investigated freshwater and brackish marsh responses to elevated salinity, greater inundation, drought, and increased nutrient loading. Elevated salinity pulses in a brackish marsh increased CO2 release from the marsh but only during dry-down. Elevated salinity increased root mortality at both a freshwater and brackish marsh. Under continuously elevated salinity in mesocosms, net ecosystem productivity (NEP) was unaffected by elevated salinity in a freshwater marsh exposed to brackish conditions (0 à 8 ppt), but NEP significantly increased with P enrichment. Elevated salinity led to a higher turnover of live to dead roots, resulting in a ~2-cm loss in soil elevation within 1 year of exposure to elevated salinity. When exposing a brackish marsh to more saline conditions (10 à 20 ppt), NEP, aboveground biomass production, and root growth all significantly decreased with elevated salinity, shifting the marsh from a net C sink to a net C source to the atmosphere. Elevated salinity (10 à 20 ppt) did not increase soil elevation loss, which was already occurring under brackish conditions, but when coupled with a drought event, elevation loss doubled. My findings suggest these hypotheses for the drivers and mechanisms of peat collapse. When freshwater marshes are first exposed to elevated salinity, soil structure and integrity are negatively affected through loss of live roots within the soil profile, leaving the peat vulnerable to collapse even though aboveground productivity and NEP may be unaffected. Subsequent dry-down events where water falls below the soil surface further accelerate peat collapse. Although saltwater intrusion into freshwater wetlands may initially stimulate primary productivity through a P subsidy, the impact of elevated salinity on root and soil structure has a greater deleterious effect and may ultimately be the factors that lead to the collapse of these marshes.

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Catenazzi, Alessandro. „The importance of marine subsidies for terrestrial consumers in coastal Peru“. FIU Digital Commons, 2006. http://digitalcommons.fiu.edu/etd/2086.

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The Peruvian coast is one the best examples of cross-ecosystem food web exchanges, in which resources from one of the richest marine ecosystems subsidize consumers in one of the driest deserts on Earth. Marine subsidies are resources that originate in the marine ecosystem, and that contribute to increase the density of consumers in the recipient ecosystem. I examined the effects of marine subsidies on animal populations in the Peruvian coastal desert. I combined several approaches to study the linkages between marine resources and terrestrial consumers, such as surveying the spatial distribution and estimating the relative abundance of terrestrial consumers, studying the diet of geckos and lizards through stomach content analyses, and examining the desert food web with carbon and nitrogen stable isotope analyses. I found that the distribution and diet of desert consumers were tightly coupled to the availability of marine subsidies. I revealed linkages along two pathways of nutrient fluxes: tidal action that washes ashore macroalgae and cadavers of marine organisms, and animal transport in places where pinnipeds and seabirds congregate for reproduction. In the first pathway, intertidal algivivores made marine resources available to terrestrial consumers by moving between the intertidal and supratidal zone. The relative contribution of terrestrial and algal carbon sources varied among terrestrial consumers, because scorpions assimilated a lower proportion of energy from macroalgae than did geckos and solifuges. In the second pathway, I found that pinniped colonies influenced the diet of desert consumers, and contributed to support large populations of lizards and geckos. By combining field observations, and stomach and stable isotope analyses, I constructed a simplified food web for a large sea lion colony, showing the number of trophic levels that originate from pinniped-derived nutrients. My study demonstrates the enormous importance of marine resources for the diet of desert consumers. The near absence of rainfall along the Peruvian coast promotes an extreme dependence of terrestrial consumers on marine resources, and causes permanent food web effects that are affected by temporal variability in marine productivity, rather then temporal patterns of desert plant growth.

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Zhang, Shuliang. „Coastal Circulations Driven by River Outflow“. NSUWorks, 1997. http://nsuworks.nova.edu/occ_stuetd/45.

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Variable-density, 11/2- and 21/2- layer models are used to examine the behavior of plumes resulting from a fresher outflow of transport Mr and salinity Sr into a pre-existing oceanic layer of initial thickness H1 and salinity S1. It is found that the plumes exhibit a variety of features depending on conditions of the outflow, the situation of the ambient ocean, and external forcing. Perhaps the most interesting feature is that the plume can flow along the upstream (to the left of the river mouth, looking seaward in the northern hemisphere) coast by itself, and the research discussed here is focused on this topic. To illustrate how density variations associated with river plumes drive circulations, several solutions of geostrophic adjustment to an initially-imposed, y-independent density front are investigated. In these solutions, a frontally-trapped alongfront geostrophic current with the fresher water to its right (facing in the current direction) is always generated in response to the initial pressure gradient across the density front. This density-driven geostrophic current is dynamically similar to that resulting from initial disturbances in layer thickness h (equivalently, potential vorticity q = f / h) in constant-density models, with low salinity (density) in the variable-density model being analogous to the low q in the constant-density model. Solutions to the 11/2-layer model driven by river outflow are fundamentally different in low-R0 (Rossby number) and high-R0 regimes. In the low-R0 case, plumes advance along both upstream and downstream coasts. If Mr is less than a critical value Mcr (determined by ΔS = Sj - Sr and H1), plumes are coastally-trapped and all the river water-first flows upstream, with some of it, together with some salty water, reversing direction near the plume nose to flow along the offshore front, this return flow passes the river mouth and continues to flow along the downstream (to the right of the river mouth) coast. When Mr > Mcr, the plumes expand offshore indefinitely, and some river water must flow downstream directly. The evolution of the river plume for the low-R0 solutions can be understood in terms of two distinct flow patterns. One is a downstream coastal current ("coastal mode") directly forced by the river transport; it is dynamically similar to the response in a linear, constant-density, 11/2-layer model, and is responsible for the downstream motion. The other is an anticyclonic circulation ("gyre mode") due to geostrophic adjustment of the river plume; the coastal current of this circulation is responsible for the upstream motion. Analytical solutions illustrate that geostrophic adjustment along the offshore density front generates the return flow and that Kelvin waves originating from the plume nose cause the upstream flow. They also allow the plume width L and the upstream nose speed c of the nose to be determined as a function of model parameters. For the high-R0 solutions, river water flows directly offshore in a narrow jet. The angle in which the jet emerges from the river mouth is found to depend on several non-dimensional parameters. Inclusion of entrainment significantly inhibits the upstream plume propagation, and makes it difficult to distinguish low-R0 and high-R0solutions. In solutions to the 21/2-layer model, the upper-layer circulation is not significantly different from that in their 11/2-layer counterparts. A pre-existing downstream coastal current significantly weakens upstream plume propagation; indeed, the upstream advance can be completely stopped if the background current is strong enough. Ekman flow and alongshore currents induced by upwelling-favorable winds push the plume offshore and upstream, whereas downwelling-favorable winds result in a coastally trapped plume that is advected downstream.

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Nilsson, Emmelie. „Algal blooms and water quality in coastal waters of Öland : Possible effect on local tourism?“ Thesis, University of Kalmar, School of Pure and Applied Natural Sciences, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hik:diva-1468.

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Utvecklingen av algblomningar i Östersjön har blivit mer diskuterat i media under senare år. Eftersom algblomningar ofta infaller samtidigt som turistsäsongen så har områden som är beroende av turistnäringen drabbats hårt. Under sommaren 2005 inträffade massiva giftiga algblomningar i Östersjön, och detta påverkade turismen på Öland negativt ur ekonomisk synpunkt. Mänsklig påverkan är ansedd vara huvudorsaken bakom den ökade förekomsten av algblomningar i Östersjön. Målet med detta projekt är att undersöka hur förekomsten av algblomningar påverkar turismen på Öland. Genom att ha samlat in vattenprover vid tre olika platser på Öland under sommaren 2007, har parametrar så som näringsstatus, temperatur, salthalt, phytoplankton sammansättning och klorofyll-a undersökts. Mängden nederbörd har observerats via data från SMHI. Detta har gjorts för att kunna studera eventuella samband mellan näringsstatus vid kusterna och möjlig avrinning från land. Två enkäter har skickats ut till samtliga camping ägare på Öland, i ett försök att se hur algblomningar har påverkat turismen under åren 2005, 2006 samt 2007. En enkät utdelades också under sommaren 2006, men denna var riktad till turisterna som besökte campingar på Öland. Ett av de slutliga målen var att undersöka hur förekomsten av algblomningar och miljöfaktorer, så som temperatur, salthalt, nederbörd och näringsämnen är sammankopplade. Provtagningsplatserna skiljde sig åt när det gällde till vilken grad de påverkats av algblomningar. Den nordvästra kusten, Köpingsvik, har nästan aldrig exponerats för algblomningar, medan den östra kusten, Gärdslösa, oftast har det. Den sydvästra kusten , Mörbylånga, har varit drabbad under vissa år. Detta material har sedan jämförts med material insamlat från 2006. Resultatet från 2007 visar på högre koncentrationer av näringsämnen och klorofyll-a jämfört med data från 2006. Resultatet från 2007 visar på högre koncentrationer av näringsämnen och klorofyll-a jämfört med data från 2006. Turismen under 2006 och 2007 visade inte ha varit negativt påverkat av algblomningar. Turismen under 2005 visade sig däremot ha varit negativt påverkat av algblomningar. Cyanobakterier förekom i lågt antal under 2006 och 2007, men andra alggrupper blommade under våren och sommaren, speciellt en grupp av sötvatten dinoflagellat kallad Peridiniopsis polonicum. Denna art förekomi höga antal i både Gärdslösa och Mörbylånga, under slutet av juli och i augusti.

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Axenrot, Thomas. „Pelagic Fish Distribution and Dynamics in Coastal Areas in the Baltic Sea Proper“. Doctoral thesis, Stockholm : Dept. of Systems Ecology, Univ, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-442.

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9

Takemura, Alison Francesca. „Niche adaptations of the vibrionaceae, from the coastal ocean to the laboratory“. Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/101791.

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Thesis: Ph. D. in Microbiology Graduate Program, Massachusetts Institute of Technology, Department of Biology, 2015.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 187-214).
Microorganisms play a significant role in biogeochemical cycling, thus their dynamics in the environment influence the biosphere. Yet how do features of the environment - such as abiotic conditions, resources, and predators - influence their activity and abundance, i.e. what constitutes their ecological niche? This study examines this question for members of a diverse marine heterotrophic family of bacteria, the Vibrionaceae. In chapter 2, I review the current knowledge of the environmental conditions and habitats in which Vibrionaceae populations are found. Through a meta-analysis of Vibrio abundance and bulk environmental variables, I show that temperature and salinity are strong correlates of Vibrio, but the patterns vary among species. By contrast, other commonly measured abiotic variables, like nitrogen and phosphate, are only weak correlates. Studies furthermore show that Vibrio engage in a diversity of lifestyles, from free-living to attached, in a wide range of habitats, though the patterns have largely not been characterized at a genetic or molecular scale. These observations motivate a finer-scale investigation of the microbial niche. In chapter 3, I explore how a single Vibrio strain is adapted to growth on different ecologically relevant resources, using nutrients extracted from habitat models - the copepod Apocyclops royi, and the brown alga Fucus vesiculosus - as well as the algal constituent, alginate. By selecting a transposon-mutant collection for growth on these resources, I find that Apocyclops is a replete resource, whereas Fucus is intermediate to Apocyclops and alginate in its anabolic requirements; that catabolic pathways have redundancy, which anabolic ones lack, that appears to mask fitness effects; and more generally, that these habitats contain complex resources that buffer fitness costs relative to growth on single carbohydrate resources. In appendix A, I determine how environmental phage isolates recognize the Vibrio strain: by its extracellular polysaccharide capsule. Losing the capsule enables the strain to resist infection from these bacteriophage; however, it suffers the tradeoff of becoming susceptible to others. By integrating environmental observations and genetic methods, this thesis provides an intimate view of the life of a marine microorganism.
by Alison Francesca Takemura.
Ph. D. in Microbiology Graduate Program

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Lauria, Mary Louise. „Physical constraints on phytoplankton in estuaries and shallow coastal waters“. Thesis, University of Southampton, 1998. https://eprints.soton.ac.uk/42128/.

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Highly dynamic aquatic systems have often been reported to support actively growing populations of phytoplankton. The partially-mixed, macrotidal, temperate estuary Southampton Water is no exception, with reports of frequent temporal patterns of spring and summer maxima in algal biomass. During this study, the close coupling between the estuarine hydrology and the phytoplankton community was confirmed by the results from an intensive sampling strategy, spanning various temporal scales. Using high frequency data, collected from acoustic Doppler current profilers (ADCP) and CTDs, the physical mixing processes within the estuary were determined and combined with high resolution phytoplankton species data to assess the physical pressures on the microalgal community. Initial surveys were conducted to provide snapshots of the estuary during productive periods, followed by more intensive, longer term monitoring to observe population growth and succession. Through seasonal investigations, the aggregation of algal biomass (quantified by chlorophyll a concentration) at differing vertical heights in the water column was realised. On closer examination using microscopic identification, the different vertical profiles were shown to be due to phytoplankton succession from the spring to the summer months. Diatoms (Rhizosolenia delicatula) proliferated in the spring, where the population was localised in the near-bottom layers, whilst the summer bloom was dominated by autotrophic dinoflagellates (Prorocentrum micans and Peridifiium trochoideum), manifesting in a sub-surface chlorophyll a maximum. The vertical position of diatom species, both pelagic and benthic, suggested no dependence on incident irradiance, but seemed solely governed by current velocities, shear and wind mixing events. Other passive constituents of the water column, such as suspended particulate matter, were also closely coupled with boundary shear and followed regular patterns of re-suspension similar to those shown by the diatom community. In the summer, apparent active vertical migration was observed for several species of dinoflagellate. Whilst this apparent migration was closely linked to the incident irradiance, the extent and timing of migration was highly dependent on the tidal state and the water column stability. During one 25 hour Eulerian investigation, apparent positive vertical migration was observed in several dinoflagellate species, where the controlling factor was incident irradiance. Dinoflagellates were observed to descend during the dark periods when the water column was stable. However, the vertical distribution of the autotrophic ciliate Mesodinium rubrum suggested that migrations into the surface waters were linked with periods of water column stability and not triggered by surface irradiance. The unique tidal regime that governs the physical mixing processes in Southampton Water translates into periods of stability separated in time by intermittent turbulence. This periodic stability within the water column during reduced tidal forcings permitted the surface aggregation of dinoflagellates, which became homogeneously distributed when turbulence intensified during the ebb and flood currents. Diatoms, conversely, relied on vertical mixing to enter the surface layers of the water column, and aggregated in the lower layers during times of water column stability. Data from the. seasonal surveys suggested that diatoms and dinoflagellates were able to co-exist during the summer by utilising contrasting properties of tidal mixing to develop and reside within this partially mixed environment. The segregation of these two phytoplankton groups was not apparent from the chlorophyll concentrations alone, and was only made evident through the high resolution phytoplankton sampling through both time and space. The close coupling between the phytoplankton community and physical forcings were also investigated in the usually well-mixed southern North Sea. During a 12 hour Lagrangian survey, the stabilising effect of the Rhine region of freshwater influence (ROFI) was recognised and provided the temporary stability necessary for apparent dinoflagellate (Prorocentrum micans and Gonyaulax so) migration. Associated solely with this lower salinity plume was the diatom Rhizosolenia stvliformis, which was not detected during other times of the survey. Very small changes in total algal biomass were detected through the use of chlorophyll a determinations (chlorophyll a < 2 mg m"3). The intermittency of the mixing forces proved to be an important physical characteristic which defines the species and distribution of the phytoplankton community.

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Brimble, Samantha. „Biotransport of marine-derived trace elements to a coastal ecosystem in the Canadian High Arctic“. Thesis, University of Ottawa (Canada), 2009. http://hdl.handle.net/10393/28261.

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Seabirds are an important link between their marine feeding areas and their terrestrial breeding environments, transporting both marine-derived nutrients and contaminants to land via their excreta, feathers and carcasses. The importance of seabird-derived nutrients is particularly apparent in nutrient poor regions like the Canadian High Arctic, where biological oases form in the area surrounding a colony. While providing the nutrient subsidies that shape the terrestrial ecosystem of many Arctic sites, seabirds may focus contaminants into their nesting sites at potentially toxic levels. Here, we investigated the impact of a large northern fulmar (Fulmarus glacialis) colony on nearby ponds spanning a broad gradient of seabird influence at Cape Vera, Devon Island. Nutrient concentrations were significantly higher in ponds receiving guano than in reference ponds. The ponds closest to the cliffs, and thus receiving the highest seabird subsidies, were the most contaminated, and in some cases exceeded Canadian Sediment Quality Guidelines for the Protection of Aquatic Life for As, Cd and Zn. This study demonstrates that seabirds can transport contaminants bioaccumulated from the ocean and funnel them into receptor sites to potentially toxic levels thousands of kilometers from industrial centers.

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Hepworth, Daniel Ary. „Response of a Partially Mixed Coastal Plain Estuary to Storm Events“. W&M ScholarWorks, 1988. https://scholarworks.wm.edu/etd/1539617584.

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Owen, Erin Fisher. „Population Structure of the Sea Scallop, Placopecten magellanicus, in Coastal Maine“. Fogler Library, University of Maine, 2008. http://www.library.umaine.edu/theses/pdf/OwenEF2008.pdf.

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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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Verspecht, Florence. „Temporal dynamics of the coastal water column“. University of Western Australia. School of Environmental Systems Engineering, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0097.

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Field measurements and numerical modelling of the shallow coastal waters offshore in south-western Australia were used to describe changes in the water column's vertical structure and the biological response on temporal scales of the order of hours and days. A cycle of chlorophyll a concentration, primary production, and photosystem II function on a diel timescale, which was related to changes in the solar irradiance and thermal structure, was identified. The diel cycle included (1) vertically well-mixed (or weakly linear) conditions in density and chlorophyll a early in the morning, resulting from vertical mixing through penetrative overnight convection; (2) depleted chlorophyll a concentration in the surface layer during the middle of the day due to photoinhibition; (3) an increased chlorophyll a concentration in the bottom layer by late afternoon due to optimum light conditions; and (4) the formation of a chlorophyll a break point (CBP) at the thermocline, which migrated downwards with the deepening surface mixed layer. On a longer timescale (days), moored acoustic instruments were used to derive echo level (EL), which approximated suspended particulate matter (SPM). Wind events ultimately controlled SPM, a conclusion based on (1) elevated EL during high windgenerated turbulence and bed shear stress, (2) positive time-lagged correlations between wind speed and EL at three field sites with different exposures to wave action, and (3) significant negative correlations between wind speed and depth-differentiated echo level (d(EL)/dz) at all sites. Sea breezes produced a similar response in EL through the water column to a small storm event, and wind-driven SPM resuspension resulted in a reduction in the sub-surface light climate (kd). Near-bed dissolved oxygen concentrations varied in accord with elevated wind speeds, EL and kd, highlighting a possible suppression of photosynthesis. One-dimensional modelling revealed that wind stirring was most often the dominant process in these waters. It was found that for a brief period during thermal stratification there was shear production of turbulent instabilities that migrated from the thermocline to the surface and the seabed. Convective cooling was not able to mix the water column entirely overnight without the addition of wind, and minimum wind speeds were determined for this complete vertical mixing. Bottom-generated turbulence was limited to a small region above the bed, and was deemed insignificant compared with mixing generated at the surface. Minimum wind speeds required for de-stratification and prevention of stratification were determined for summer, autumn and winter. A hypothetical desalination outfall was simulated for all seasons and it was concluded that positioning of the discharge at middepth was preferable compared to at the seabed. The results of this thesis advance the current knowledge of coastal biophysical oceanography and provide new insights into the temporal dynamics of the coastal water column of south-western Australia.

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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.

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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.

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Sinclair, Michael N. „Facilitative and competitive tradeoffs between Morella cerifera seedlings and coastal grasses“. VCU Scholars Compass, 2019. https://scholarscompass.vcu.edu/etd/5872.

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Morella cerifera is a rapidly expanding native shrub on the Virginia barrier islands which displaces other native coastal species and may interrupt normal sediment dynamics. Barrier islands are considered stressful environments with low nutrients, high solar load, and frequent drought and salt exposure; facilitation often dominates in stressful environments according to the Stress Gradient Hypothesis. The objective of this project was to understand the importance of species interactions with grasses on the growth and physiology of M. cerifera at the seedling life stage through both field and lab experiments. Grasses provided ~1.3°C insulation to shrubs during winter freeze events and a freezing threshold for M. cerifera seedlings was experimentally found between -6°C and -11°C. Seedlings competed for light with grasses during warm months and grew more where grasses were clipped, revealing a tradeoff between winter insulation and summer light competition. M. cerifera shows evidence of ecosystem engineering at the seedling stage by significantly reducing summer maximum temperatures. This enables rapid expansion of M. cerifera across the landscape. As M. cerifera expands, island migration is altered, leading to decreased island stability and increased erosion. Although seedlings are small and relatively vulnerable, this life stage appears to have significant implications for the ecosystem trajectory and stability of the Virginia barrier islands.

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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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Peterson, Cassidy. „Patterns of Abundance and Community Dynamics in Atlantic Coastal Sharks“. W&M ScholarWorks, 2016. https://scholarworks.wm.edu/etd/1539617961.

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Rhode, Michael P. „Dynamics of the larval fish assemblage at two coastal Delaware Inlets“. Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 65 p, 2008. http://proquest.umi.com/pqdweb?did=1605136741&sid=5&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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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.
Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 709

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Ray, Robert Triau. „The Role of Picoplankton in Phytoplankton Dynamics of a Temperate Coastal Plain Estuary“. W&M ScholarWorks, 1986. https://scholarworks.wm.edu/etd/1539617566.

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Da, Fei. „Impacts of Atmospheric Nitrogen Deposition and Coastal Nitrogen Fluxes on Chesapeake Bay Hypoxia“. W&M ScholarWorks, 2018. https://scholarworks.wm.edu/etd/1530192498.

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Although rivers are the primary source of dissolved inorganic nitrogen (DIN) inputs to the Chesapeake Bay, direct atmospheric DIN deposition and DIN fluxes from the continental shelf can also significantly impact Chesapeake Bay hypoxia. The relative role of these additional sources of DIN has not previously been thoroughly quantified. In this study, the three-dimensional Estuarine-Carbon-Biogeochemistry model embedded in the Regional Ocean Modeling System (ChesROMS-ECB) is used to examine the relative impact of these three DIN sources. Model simulations highlight that DIN inputs from the atmosphere have roughly the same impact on hypoxia as the same gram for gram change in riverine DIN loading. DIN inputs from the shelf have a similar overall impact on hypoxia as those from the atmosphere (~0.2 mg L-1), however the mechanisms driving these impacts are different. While atmospheric DIN impacts dissolved oxygen (DO) primarily via the decomposition of autochthonous organic matter, coastal DIN also impacts DO via the decomposition of allochthonous organic matter entering the Bay from the continental shelf. The impacts of coastal and atmospheric DIN on estuarine hypoxia are greatest in the summer, and occur farther downstream (lower mesohaline) in wet years than in dry years (upper mesohaline). Integrated analyses of the relative contributions of all three DIN sources on summer bottom DO concentrations indicate that impacts of atmospheric deposition are largest in shallow near-shore regions, riverine DIN has dominant impacts in the largest tributaries and the oligohaline Bay, while coastal DIN fluxes are most influential in the polyhaline region. During the winter when estuarine circulation is strong and shelf DIN concentrations are relatively high, coastal DIN impacts bottom DO throughout the Bay.

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Keung, Neil C. „Longitudinal distribution and summer diurnal microhabitat use of California Red-Legged Frogs (Rana draytonii) in coastal Waddell Creek“. Thesis, San Jose State University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1593144.

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Habitat use by federally threatened California Red-Legged Frogs (CRLF; Rana draytonii) is incompletely understood. I captured, PIT-tagged, and radio-tracked CRLFs (n = 20) at Waddell Creek, Santa Cruz County, from July–December 2012. Limited tracking for movements was also conducted in 2013. Frogs were clumped in deep, complex habitats along the stream within 2 km of breeding ponds near the stream mouth, but most adults were concentrated in the lagoon. Marked and tracked frogs had very small summer home ranges, and most returned to the same home range after breeding. Frogs tended to use good aquatic (e.g., wood, undercut banks, dense willows) and bank cover (e.g., ground vegetation, wood) at all times but used open habitats more at night than during the day. Visual night surveys were biased against cryptic frogs compared to radio-tracking results. Early fall rains increased upland habitat use, but later heavy winter rains were needed to trigger migration to breeding sites and subsequent breeding. Site-specific studies using radio-tracking are needed to design protections for breeding, migration, and nonbreeding habitats.

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Garman, Keith Michael. „The Biogeochemistry of Submerged Coastal Karst Features in West Central Florida“. Scholar Commons, 2010. http://scholarcommons.usf.edu/etd/3444.

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West Central Florida is a complex karst environment with numerous sinkholes, springs, and submerged cave systems. Many of these karst features are anchialine, located within the subterranean estuary where freshwater and saltwater mix. Water quality data and/or fauna data were obtained from twenty-one karst features and their associated cave systems. The anchialine karst environment of the study area has a wide range of habitats with measured salinities ranging from freshwater at <0.2 ppt to sulfidic, hypersaline water at 38.5 ppt and measured pH readings ranging from 6.39 in water impacted by sulfur oxidizing bacteria to 10.3 in an isolated room of a cave. Stygobitic crustaceans were identified in conduits extending beneath the Gulf of Mexico supporting the hypotheses that freshwater crustaceans could survive higher sea levels in freshwater conduits beneath saltwater. The fauna associated with the anchialine cave systems included Sabellidae and Polychaeta worms, hydroids, cnidarians and hydrobiid snails. Jewfish Sink, like other anaerobic marine basins that were submarine springs, has four zones: oxic zone, transition zone, upper anoxic zone and anoxic bottom water. The upper zones have seasonal water quality variations from winter cooling and sinking of surface water and changes in the microbial communities. Activity of sulfate reducing bacteria is carbon limited in the anoxic zones, where sulfate reduction is the major metabolic process, and primary production is phosphate limited in the oxic zones. Organic input from the Gulf of Mexico drives the bacterial anaerobic ecosystem, resulting in a “sulfide pump”, in which sulfide percolates upward removing oxygen from the overlying sediment.

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Goodwin, Candice Michelle. „Investigations into actinomycetes isolated from coastal environments, with a special emphasis on the genus Micromonospora“. Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/4267.

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Includes bibliographical references.
Marine environments were investigated and actinomycetes were isolated on selective media. Thirty-four (34) actinomycete strains were isolated and identified: 21 Micromonospora strains, 10 Streptomyces strains, and 3 Pseudonocardia strains. A polyphasic approach was employed to determine the novelty of the isolates. Potentially, all 21 Micromonospora strains are novel, as revealed by an original identification scheme developed to assess quickly and easily the novelty of newly isolated environmental Micromonospora strains. Standardized media for testing physiological characters of Micromonospora strains were developed, and additional physiological characteristics of 15 of the validly published members of the genus Micromonospora are described. Furthermore, 14 of the 15 validly published Micromonospora species, and 20 of the 21 environmental Micromonospora isolates grew under anaerobic conditions.

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McAtee, Kaelin J. „Impact of Sediment Augmentation on Plant and Invertebrate Communities in a Southern California Coastal Wetland“. Thesis, California State University, Long Beach, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10686752.

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As sea levels rise, management strategies are needed to protect coastal wetlands from increased inundation. Sediment augmentation is a strategy in which a layer of sediment is sprayed across the marsh to raise the marsh's elevation and reduce inundation. This study looks at the short-term impact of sediment augmentation on vegetation and invertebrate communities. Abiotic measurements, invertebrate cores, and plant parameters were analyzed before and after augmentation in a before-after-control-impact (BACI) design. Following augmentation there was a significant decrease in plant cover and invertebrate abundance. The community composition of invertebrates shifted from a dominance of oligochaetes and polychaetes to insects and insect larvae. At six months following augmentation, Salicornia bigelovii began growing throughout the augmentation area, and Spartina foliosa had returned via vegetative spread at the edges of the marsh. Detailing these changes provides information on the ecological impacts of sediment augmentation for this site and inform regional management strategies.

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Reeder, Brian Charles. „Primary productivity, sedimentation, and phosphorous cycling in a Lake Erie coastal wetland“. Connect to resource, 1990. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1244210231.

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Herrington, Twyla. „Socioeconomic Characteristics of Coastal Pelagic Fishing Tournaments in South Florida“. NSUWorks, 2011. http://nsuworks.nova.edu/occ_stuetd/203.

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Highly migratory species (HMS) are targeted in numerous recreational fishing tournaments in the Florida Straits and very important to the total directed fisheries for these species. Sailfish Istiophorus platypterus and wahoo Acanthocybium solandri are primary coastal pelagic fish species, found in similar shelf-edge habitats, targeted in these recreational tournaments. The economic importance of these tournaments is unknown, as is the probable overlap between tournament fisheries by anglers targeting this species. A voluntary mail survey was administered to two sailfish tournaments and one wahoo tournament within the Florida Straits during the 2009/2010 season. Questions were organized into four sections: general fishing activity and experience, tournament experience, fishing techniques, and personal angler characteristics. Response rates for the participating tournament were as follows: Stuart Sailfish Club Light Tackle Sailfish Tournament (SSCLT), 23.3%, Silver Sailfish Derby (SSD) 44.2%, and Bahamas Wahoo Championship (BWC) 33.0%. All participating tournaments represented an overwhelmingly male population (SSCLT 92.9%; SSD 94.7%, BWC 100%), the majority of which were residents of Florida. Sailfish was listed as the preferred target species for the participating sailfish tournament anglers with wahoo being listed as the preferred target species for wahoo tournament participants. All anglers in both sailfish tournaments responded yes to participation in the upcoming year’s tournament with only 50% of wahoo participants answering yes to this question for next year’s participation. Average tournament expenditures and economic contributions were part of the results from this study. All tournaments showed highest expenditures under gas and oil for boats. The SSCLT tournaments average for oil and gas totaled $2,785.00 for the tournament, the highest of the three tournaments surveyed. Lodging was shown to be the least important of all categories with averages ranging between $325-$700 per tournament. The direct economic contribution from each tournament as whole to the local economy were as follows: SSD- $425,109; SSCLT- $866,189; Wahoo-$71,550. These numbers correspond to the total tournament participation numbers with the highest contribution and participation being the SSCLT tournament. Understanding angler preferences and expenditure patterns will help tournament directors and local fisheries management agencies better understand the economic importance and management implications in South Florida.

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Stephens, Nicole R. „Stony Coral Transplantation Associated with Coastal and Marine Construction Activities“. NSUWorks, 2007. http://nsuworks.nova.edu/occ_stuetd/258.

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Coral reefs in Broward County are increasingly threatened by coastal and marine construction activities. Infrastructure installation (cables, pipelines, and sewer outfalls), beach renourishment, and dredge and fill operations have both anticipated and inadvertent impacts which may result in reef damage. Mitigation practices consisting of impact avoidance and minimization are necessary to prevent and offset reef damage. Coral transplantation is a commonly utilized impact minimization tool which aims to protect corals threatened by impending construction projects. Coral colonies are removed from their natural habitats and relocated to analogous unthreatened sites prior to construction. This study focuses on coral transplantation that occurred as impact minimization for two recently completed coastal and marine construction projects in Broward County. The first project involved relocation of colonies to natural reef away from potential damage by a natural gas pipeline geotechnical survey. The second project involved relocation of colonies to an artificial reef in relation to a beach renourishment project. Colonies from both projects were monitored and analyzed in regards to survival and growth to determine transplantation success. A combined 1100 colonies were transplanted for these projects, with approximately 25% of these chosen for 18-24 months of monitoring. The projects had high attachment rates between 92-100% and survival rates between 87-99%. A majority of colonies exhibited positive growth at an average rate of 0.03%-0.04% of initial tissue area per day. There were no apparent detrimental effects of transplantation such as reduced initial growth rates, disease, bleaching, or increased partial mortality. These results indicate that coral transplantation was highly successful from a biological standpoint. This study also demonstrates that coral transplantation is a valid and effective component of impact minimization whereby colonies that may otherwise be destroyed, can be successfully preserved. For this study, coral transplantation proved to be an economically worthwhile method of conserving an ecologically and economically valuable reef resource. However, coral transplantation is only one facet of impact minimization and mitigation. Ideally, future mitigation projects should also aim to reduce habitat loss and preserve biota in addition to stony corals.

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Goulet, Raphaël. „Aspects of the ecology of urban-nesting Bald Eagles («Haliaeetus leucocephalus») in South-coastal British Columbia“. Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=86762.

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In the past decade, Bald Eagle populations throughout North America have increased considerably and, despite their previous known avoidance of humans, eagles have begun invading cities in large numbers. The overall aim of this study was to document the ecology of urban Bald Eagle populations living in south-coastal British Columbia. We conducted a comparative study of the nest-site characteristics, productivity, and feeding habits of over 150 breeding pairs of rural, suburban and urban eagles. Tall mature trees are especially important for urban eagles and suburban areas have greater concentrations of nests. Nesting success and productivity for this population are some of the highest figures in North America. Human land-use and proximity to habitat edge are strongly linked to productivity and crows, gulls and pigeons are the most popular prey items for urban eagles. This study is expected to have implications for future management strategies of Bald Eagles in human-altered landscapes.
Dans les dernières décennies, les populations de pygargue à tête blanche ont considérablement augmenté partout en Amérique du Nord, et étonnement dans les milieux urbains. L'objectif de cette étude est de documenter l'écologie des populations urbaines de pygargues dans le sud-ouest de la Colombie-Britannique. Nous avons comparé les caractéristiques des sites de nidification, la productivité et les habitudes alimentaires de 150 paires d'individus vivant en milieux ruraux, sous-urbains et urbains. Les grands arbres sont spécialement important pour les aigles urbains, les banlieues démontrent de plus grandes concentrations de nids, la productivité de cette population est l'une des plus élevées de la distribution et est fortement liée à l'occupation humaine et la proximité des zones de transition d'habitat. Les corneilles, goélands et pigeons sont les proies les plus prisées par les aigles urbains. Cette étude risque d'influencer la gestion des pygargues dans les environnements partagés avec les humains.

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Hucks, Katrina D. „Evaluation of Maximum Entropy Models for Assessing the Influence of Restoration Scenarios on Coastal Wildlife Populations“. Thesis, University of Louisiana at Lafayette, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10268262.

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Coastal systems are facing many challenges including climate change, sea-level rise, storm surge, and erosion, all of which contribute to land loss. In Louisiana, this has led to the development of a coastal Master Plan supported by habitat suitability index (HSI) models to predict wildlife responses under various management scenarios. However, these models were not originally intended for this purpose and their functionality at large spatial scales is unclear. My goal was to use maximum entropy modeling, using the software MaxEnt, to predict how various bird distributions might change with coastal restoration and management. During 2015-2017, I recorded the locations of brown pelican, gadwall, green-winged teal, mottled duck, and roseate spoonbill across southern Louisiana, measuring salinity, water depth, and vegetation when the species were detected. Using environmental projections from the Coastal Protection and Restoration Authority, I predicted the probability of occurrence for each target species for current conditions and projected the distributions into the future at 25 and 50 years using sea-level rise and coastal change scenarios. Predictive models for each species under current conditions show good agreement with field observations. Future models generally show reductions in areas of potentially high habitat use, with a few notable exceptions in brown pelicans and roseate spoonbills. Both modeling approaches had advantages and disadvantages; neither were superior in predicting wildlife habitat. I recommend increasing the resolution and quality of environmental data to improve estimates of suitable habitat, habitat use, and restoration outcomes for wildlife.

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White, Geoffrey Gordon. „Reproductive Biology of Tautog, Tautoga onitis, in the Lower Chesapeake Bay and Coastal Waters of Virginia“. W&M ScholarWorks, 1996. https://scholarworks.wm.edu/etd/1539617702.

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Liu, Xiao. „Ecological, Physiological, and Bio-Optical Characteristics of Phaeocystis globosa in Coastal Waters of South Central Vietnam“. W&M ScholarWorks, 2011. https://scholarworks.wm.edu/etd/1539617903.

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Horaist, David W. „Estimating Seed Bank Responses to Changing Environmental Conditions in the Louisiana Coastal Zone“. Thesis, University of Louisiana at Lafayette, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10002484.

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The coastal zone of Louisiana is changing due to multiple pressures associated with sea-level rise, subsidence, and the inability of sediment or organic accretion to keep pace. The expected increases in sea level and salinity may affect the distribution of the existing plant communities. In addition, these changes in the environment could lead to shifts in plant community composition. During the summer of 2014, I researched how changes in salinity and water levels may change the establishment of vegetation in Louisiana marshes. Randomly selected Coastwide Reference Monitoring System (CRMS) sites were used to collect vegetation data and soil samples. The collected soil samples from fresh, intermediate, brackish, and saline marsh sites were used in a seed bank study. The seed bank study evaluated the effects of different levels of salinity and flooding on seed germination and species richness. Seed germination was highest in soil samples collected from fresh and intermediate sites when these samples were exposed to low salinity (0.0 ppt) and non-flooded conditions. My study only found 43 seedlings in the 10 ppt treatment of 336 total seed germinations, and only 2 seedlings were found in the 20 ppt salinity treatment. Salinity was the dominant factor governing seed germinations and species richness. I also determined that the parent plants for the species found in my seed bank study were more likely to be found within the study site. However, the species data showed at least one species or genus was not present in either the historical or the field collected data. Therefore, the dispersal distance of some seeds from their parental seed provider could have been several hundred meters.

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Johnson, Jaimie L. „The Aquatic Community Associated with Native and Invasive Macrophytes in Lake Erie Coastal Wetlands“. Bowling Green State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1535382268156399.

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Strand, Sarah Elise. „Stable Isotope Biogeochemistry of South Florida Coastal Marine Ecosystems“. FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1737.

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Southeast Florida’s continual urban expansion will potentially increase anthropogenic pollution in adjacent coastal marine systems. Furthermore, increased nutrient loads could have detrimental effects on the already threatened Florida Reef Tract. The present study uses a stable isotopic approach to determine the sources and the impact of nutrients on the Florida Reef Tract. δ13C and δ15N analysis of macroalgae, sponges, and sediment were analyzed in order to determine nutrient inputs in this region. While δ13C data did not display any significant trends spatially, δ15N values of the majority of biota exhibited a strong East to West gradient with more enriched values close to shore. Relative enrichment in δ15N values were measured for sediments sampled along the Florida Reef Tract in comparison to a pristine Marquesas Keys sediment core. The δ15N data also implies that shoreline anthropogenic nutrients have more nutrient loading implications on reefs than major point sources.

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Maxey, Johnathan Daniel. „Shedding Light on the Estuarine Coastal Filter: The Relative Importance of Benthic Macroalgae in Shallow Photic Systems“. W&M ScholarWorks, 2012. https://scholarworks.wm.edu/etd/1539617924.

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Slocum, Kevin R. „Coastal zone landscape classification using remote sensing and model development“. W&M ScholarWorks, 2002. https://scholarworks.wm.edu/etd/1539616857.

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Coastal zone landscape characterization and empirical model development were evaluated using multi-spectral airborne imagery. Collectively, four projects are described that address monitoring and classification issues common to the resource management community. Chapter 1 discusses opportunities for remote sensing. Chapter 2 examines spectral and spatial image resolution requirements, as well as training sample selection methods required for accurate landscape classification. Classification accuracy derived from 25nm imagery with 4m pixel sizes outperformed 70nm imagery with 1m pixel sizes. Eight natural and five cultural landscape features were tested for classification accuracy. Chapter 3 investigated the ability to characterize 1m multispectral imagery into rank-ordered categorical biomass index classes of Phragmites australis. Statistical clustering and sample membership was based upon normalized field-measurements. The red imagery channel showed highly significant correlation with field measurements (p = 0.00) and explained much of its variability (r2 = 0.79). Addition of near-infra red, green, and blue image channels in a forward stepwise regression improved the coefficient of determination (r2 = 0.98). In Chapter 4, a landscape cover map was revised by incorporating expert knowledge into a simple spatial model. Examples are provided for a barrier island environment to illustrate this post-classification methodology. A prototype selection of expert rules was sufficient to change more than 20 per cent of the originally classified landscape pixels. Chapter 5 discusses the development of an empirical model that uses vegetation community classes to estimate: (a) soil type, (b) soil compaction rate, and (c) elevation. Vegetation class proved itself a reliable surrogate for estimating these variables based upon field-based statistical measures of association and significance tests. Vegetation was highly associated with four soil types (Cramer's V = 0.98) and soil compaction rates values at depths of 30 and 46cm (Cramer's V > 0.85), and was able to accurately estimate three decimeter-level elevation zones (r2 = 0.86, p = 0.00). A preliminary model to estimate transverse dune crest heights and locations under forest canopy was presented. Lastly, Chapter 6 offers a summary and concluding statements advocating continued use of remote sensing as an application tool for resource management needs.

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Shepheard-Walwyn, Emma. „Culture and conservation in the sacred sites of coastal Kenya“. Thesis, University of Kent, 2014. https://kar.kent.ac.uk/48959/.

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The Mijikenda sacred natural sites (SNS) contribute towards Kenya’s East African Coastal Forest ecosystem. This ecosystem is highly biodiverse and important to the conservation of many rare and endemic species. The SNS are therefore thought to be very important to biodiversity locally and globally, as well as playing a significant role in the preservation of the local traditional culture. Whilst it is known that the SNS contain coastal forest, there are no accurate estimates on the amount, nor are there assessments of habitat diversity within the sites and no systematic surveys have been done in the past 20 years. In addition, degradation of the sites has been described, but the level of encroachment and amount of forest loss has not been measured. A major driver of the degradation and deforestation of SNS is thought to be cultural change, leading to a decrease in the adherence to traditional practices, and loss of knowledge and respect for local customs. The existing management of the SNS is based on the traditional laws associated with the SNS; enforcement is left to local Kaya Elders, and it follows the assumption that the Mijikenda are a homogenous and culturally static group. As such it is thought that changes in culture and values systems may be undermining the successful conservation of the sites. However, again, whilst changes within the local communities surrounding the SNS have been described, no research has been done on how such changes may have altered the attitudes and values of the local people in this region, or what impact this may have on the preservation of the SNS. The aims of this thesis are to: measure the amount of costal forest within the Mijikenda SNS; to assess if the habitat heterogeneity within the sites; investigate their potential for biodiversity; measure the amount of forest loss within the sites, and the amount of encroachment that they suffer from; understand the current attitudes and values of the local communities towards the SNS, their culture, and conservation; compare current attitudes and values to what would be expected traditionally; investigate the use of resources from the Kayas by the local communities; and, in light of these questions, assess the efficacy of the existing management plan in light of the current landscape in which the SNS are located and any changes in local culture, and associated values. The results show that the Mijikenda SNS contain a substantial proportion (1.4%) of Kenya’s coastal forest. Due to their habitat heterogeneity and habitat features, as well as being some of the only forest habitat within a degraded landscape, they are important to both local and global conservation, including the possibility to maintain viable populations of rare and endemic species. Whilst the rate of forest loss within the SNS was found to be significantly lower than forest loss outside the sites, almost all sites were undergoing encroachment, degradation and forest loss. The local communities were found to be diverse, with different demographics, attitudes, values and behaviours. There has been a significant departure from the traditional culture, including a decrease of participation in traditional practices, a lack of adherence to customary laws, and a loss of traditional knowledge. The SNS were found to be important for resources to the local communities; however, extraction is not being monitored or managed for. In addition, ongoing developments in the region could pose a significant threat to the SNS. This research provides the first set of accurate estimations of coastal forest within the sites, and the range of habitat heterogeneity and potential contribution to biodiversity they make. It also offers the first set of accurate measurements, of the extent of encroachment, and forest loss, that a number of sites on the north coast have undergone. In addition it provides some of the only large-scale social data associated with the Mijikenda SNS. This thesis shows that whilst some of the threats to the sites, and changes in local culture have been observed in the past, none have been accounted for in the current management plans associated with the sites. The management of the SNS needs to be redesigned to account for the changes within the local communities and the surrounding area, as well as addressing the threats that the SNS face. Management should be created on a site-by-site basis, to work with all stakeholders in the area, and must encompass the changes which are happening within the region. In addition, interventions to address conflicts within communities, provide alternative access to resources, and to improve transmission of knowledge, need to be put in place to aid communities in protecting the SNS. Management of the sites must be done jointly by the local people, the government, and NGOs, with the local communities predominantly having autonomy over the protection of the sites and their culture. This research contributes to the understanding of the roles that SNS play in the conservation of biodiversity; and the issues that arise for the conservation of traditionally managed sites of communities undergoing cultural change. It will help to provide information which can be used to address the management of the Mijikenda SNS as well as SNS and community conserved areas around the world.

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Cope, Jeff A. „Coastal squeeze of vegetation zones in the Los Cerritos Wetlands| The effect of sea level rise“. Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1583669.

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This project assesses the elevation of several vegetation zones of the Los Cerritos Wetlands in Southern California to determine the possible effects of sea level rise on the salt marsh vegetation, the foundation of coastal salt marsh ecology. Steamshovel Sough in the Los Cerritos Wetland contains ideal habitat for the project. This coastal salt marsh is unique in that it abuts artificial elevation gradients of urban development on all sides. The confined nature of the wetland restricts its ability to adjust to future sea levels, a process known as coastal squeeze, which calls the sustainability of this scarce ecosystem into question. In-situ surveying of indicator species Parrish's Glasswort and Pacific Cordgrass (Arthrocnemum subterminale and Spartina foliosa) revealed the habitat elevations above sea level. Modelling various sea level rise scenarios using the habitat ranges determined through in-site surveying reveal expected future habitat zones. Los Cerritos Wetland has a notable susceptibility to sea level rise because of topographic convolutions created by local urban development. One and two foot sea level rise scenarios project substantial zone shifts resulting in pronounced winners and losers. The results here highlight the delicacy of the marsh and its intimate relationship to sea level, and hold a powerful utility to restoration project managers seeking to create a salt marsh that reflects the natural distribution of various habitats and which possesses longevity in the face of the changing environment.

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Frank, Julie. „Factors Affecting Dissolved Oxygen Metabolism in Coastal Plain Streams of Virginia“. VCU Scholars Compass, 2009. http://scholarscompass.vcu.edu/etd/1791.

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I investigated seasonal and inter-site variation in factors influencing diel dissolved oxygen (DO) metabolism at four streams in the Virginia Coastal Plain. Data were collected monthly from January to August 2008 to characterize DO metabolism (diel DO amplitude, production, respiration), incident solar radiation (PAR), dissolved nutrients, fine benthic materials (mass, C:N, Chlα) and hydrology (discharge, water transit time, transient storage). Reach-scale metabolism estimates were determined using the one-station diurnal DO technique and transit time and transient storage were determined by conservative tracer additions. Incident solar radiation was the primary determinant of DO metabolism as streams experiencing higher light levels (Herring and Powell Creeks) exhibited greater diel DO amplitudes, production and respiration. Streams with greater riparian shading (Courthouse and Crump Creeks) exhibited lower DO metabolism despite their higher nutrient concentrations. Higher incident solar radiation was associated with greater benthic algal biomass at some (Herring, Crump, and Courthouse Creeks) but not all (Powell Creek) sites. Diel DO amplitudes were significantly and positively correlated with benthic Chlα and incident solar radiation at less shaded sites. These factors were not significant predictors of DO amplitude, production or respiration at more shaded sites.

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Wagner, Clifford Michael. „Correspondence between Environmental Gradients and the Assemblage Structure of Littoral Fishes in the Tidal Portion of Three Virginia Coastal Plain Rivers“. W&M ScholarWorks, 1997. https://scholarworks.wm.edu/etd/1539617729.

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Huntley, John Warren. „Evolution of predation-related characters in neogene Atlantic Coastal plain corbulids and lucinids /“. Electronic version (PDF), 2003. http://dl.uncw.edu/etd/2003/huntleyj/johnhuntley.pdf.

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Cazier, Penelope Williams. „Hardwood Forest in the Coastal Plain of Virginia East of the Suffolk Scarp“. W&M ScholarWorks, 1992. https://scholarworks.wm.edu/etd/1539625724.

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46

Vogel, Catherine. „The Occurrence of Higher Filamentous Fungi and Yeasts in Two Coastal Subtropical Habitats“. NSUWorks, 2003. http://nsuworks.nova.edu/occ_stuetd/102.

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This study addresses the fungi of two poorly studied subtropical coastal habitats: a mangrove site and recreational sandy beaches. Little is known regarding the occurrence and distribution of the higher filamentous fungi in mangroves of South Florida. Previous studies have demonstrated that marine fungi are an important degradative component and assume an important role in nutrient recycling systems in estuarine and near-shore ecosystems. In this study over 30 species of higher filamentous fungi were identified from driftwood collected in the mangroves in J.U. Lloyd State Park over a period of one year. The drift wood collected was mainly comprised of pieces of Rhizophora mangle and Conocarpus erectus. The predominant species, by frequency of occurrence, include the Ascomycetes Hypoxylon oceanicum (8.7%), Leptosphaeria australiensis (15.6%), Lulworthia grandispora (5.2%), and Nais glitra (11.6%) as well as the Fungi Imperfecti Humicola alopallonella (5%) and Cirrenalia species (6.4%). A new record for Florida is the Ascomycete Massarina velatospora, and a new host record for Phaeosphaeria gessneri occurring on R. mangle is reported. In addition, a description of two undescribed ascomycetous species is included. Overall, the marine mycota of South Florida appears to be very similar to that reported for other tropical and subtropical regions. Another site with important overlooked fungal components is the sand of bathing beaches. The second purpose of this study was to obtain mean counts of colony forming units (CFUs) of yeasts from the wet and dry sand of three bathing beaches in South Florida. The different yeast species were also isolated and identified, using molecular methods, in order to see whether there are any pathogenic species that grow in the sand. A total of 21 yeast species were identified including 4 Basidiomycetes and 17 Ascomycetes. Several species are known to be human pathogens. The most frequently occurring species included the Ascomycete Candida tropicalis and the Basidiomycete Rhodotorula mucilaginosa. Both species diversity and total mean counts of CFUs were found to be higher in the dry sand vs the wet sand, probably as the result of a more stable habitat. Mean counts were highest at the most crowded beach, suggesting that humans and warm-blooded animals may serve as a source of contamination of the sand.

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DiGiamberardino, Tony. „Changes in a South East Florida Coastal Ecosystem After Elimination of Casuarina equisetifolia“. NSUWorks, 1986. http://nsuworks.nova.edu/occ_stuetd/90.

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As we have become more aware of the value of vegetation in the stabilization of coastal sand dunes, there has been an increasing desire to protect valuable native species in coastal habitats. In Florida, introduced exotic species have tended to crowd and eventually replace native vegetation, resulting in the establishment of monocultures. The Australian pine (Casuarina eguisetifolia) introduced to south Florida in 1898 by Fairchild, has become a weed species on beaches, supressing the native grasses associated with dune formation by its exudation of allelopathic substances. A Casuarina eradication project in Jupiter Island (Martin County), Florida was conducted in an attempt to slow beach erosion by allowing reestablishment of native dune forming grasses. Empirical data was obtained from this area to determine: 1. the effects of the loss of a dominant tree species, 2. the changing of the floristics of the area demonstrating subsequent growth of native vegetation, 3. the species reactions to different degrees of soil's salinity and pH. Throughout the study area (Casuarina stand), the elimination of Casuarina resulted in an immediate growth of four species (Ipomoea pes-caprae –railroad vine, Paspalum vaginatum -salt joint grass, Panicum amarulum -panic grass, Uniola paniculata -sea oats ). I. pes-caprae is an opportunistic species representing an early stage of succession while P. vaginatum, P. amarulum, and U. paniculata are members of the climax community. Diversity indices declined after Casuarina eradication due to the initial rapid growth of I. pes-caprae, however significant linear or exponential growth of the native grasses was observed. It was found that the growth rates vary significantly with season. Away from the immediate shore line, maximum growth for all species occurred from mid to late summer. Highest growth rates for the majority of species occurred on a nearby natural dune (control) site, except for two species (I. pes-caprae and P. vaginatum) which were found to be most abundant throughout the (Casuarina stand) disturbed site.

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Welch, Bradley A. „Phragmites Australis : response to wave exposure gradients, substrate characteristics, and its influence on plant species diversity in a Lake Erie coastal marsh /“. The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486401895209592.

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McFarland, Jason J. „Trophic pathways supporting Arctic Grayling in a small stream on the Arctic Coastal Plain, Alaska“. Thesis, University of Alaska Fairbanks, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1588386.

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Arctic Grayling (Thymallus arcticus) are widely distributed on the Arctic Coastal Plain (ACP) of Alaska, and are one of the few upper level consumers in streams, but the trophic pathways and food resources supporting these fish are unknown. Grayling migrate each summer into small beaded streams, which are common across the landscape on the ACP, and appear to be crucial foraging grounds for these and other fishes. I investigated prey resources supporting different size classes of grayling in a beaded stream, Crea Creek, where petroleum development is being planned. The specific objectives were to measure terrestrial prey subsidies entering the stream, quantify prey ingested by Arctic Grayling and Ninespine Stickleback (Pungitius pungitius ), determine if riparian plant species affect the quantity of terrestrial invertebrates ingested by grayling, and determine if prey size and type ingested were a function of predator size. Results indicated that small grayling (< 15 cm fork length (FL)) consumed mostly aquatic invertebrates (caddisflies, midges, and blackflies) early in the summer, and increasing quantities of terrestrial invertebrates (wasps, beetles, and spiders) later in summer, while larger fish (> 15 cm FL) foraged most heavily on stickleback. Riparian plant species influenced the quantity of terrestrial invertebrates entering the stream, however these differences were not reflected in fish diets. This study showed that grayling can be both highly insectivorous and piscivorous, depending upon fish size class, and that both aquatic and terrestrial invertebrates, and especially stickleback, are the main prey of grayling. These results highlight the importance of beaded streams as summer foraging habitats for grayling. Understanding prey flow dynamics in these poorly studied aquatic habitats, prior to further petroleum development and simultaneous climate change, establishes essential baseline information to interpret if and how these freshwater ecosystems may respond to a changing Arctic environment.

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Wood, Michael David. „Assessing the impact of ionising radiation in temperate coastal sand dune ecosystems : measurement and modelling“. Thesis, University of Liverpool, 2010. http://livrepository.liverpool.ac.uk/1359/.

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This thesis presents the results of a 6-year research project to investigate the radioecology of temperate coastal sand dunes. Samples (n = 617) of soil, water and biota were collected from the Drigg coastal sand dunes (West Cumbria, UK) between February 2005 and October 2007. Biota groups sampled included amphibians, birds, invertebrates, mammals, reptiles, plants (including lichens and mosses) and fungi. All samples were analysed for 40K, 137Cs and 241Am. A sub-set of samples (n = 26) was analysed for 90Sr, 99Tc, 238Pu and 239+240Pu. Additional soil analyses included soil moisture, bulk density, pH, organic matter content, carbonate content and cation concentrations (Ca2+, K+, Na+ & Mg2+). The application of three publicly-available environmental radiation protection models (ERICA, R&D128/Sp1a & RESRAD-BIOTA) to an assessment of ionising radiation impacts at the Drigg coastal sand dunes site was evaluated. Soil activity concentration data were used as input data and model results compared with measured activity concentrations in sand dune biota. Radionuclide concentration ratios (CRs) were identified as an important source of variation in model predictions. For sand dune small mammals, Am, Cs and Pu CRs were found to be 1 – 2 orders of magnitude lower than those for small mammals in other terrestrial ecosystems. For reptiles, the variability could be attributed to the paucity of data on transfer to this vertebrate group. Through literature review, mining of unpublished data sets and analysis of samples collected from the Drigg coastal sand dunes, CR databases were developed for reptiles (across a range of ecosystem types) and for sand dune biota. Analysis of sand dune soil data suggested that both sea-to-land transfer and the transport of sand grains in saltation influence the soil activity concentrations in coastal sand dunes. The low CRs for sand dune biota may be due to low bioavailability of particulate-bound radionuclides.

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Dissertationen zum Thema „Coastal biology“

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