Spelling suggestions: "subject:"virginia islands""
21 |
Predicting leatherback sea turtle sex ratios using spatial interpolation of nesting beach temperaturesUnknown Date (has links)
Sex determination in leatherback sea turtles is directed primarily by the temperatures a
clutch experiences during the middle third of development. Warmer temperatures tend to produce females will cooler temperatures yield males. Nest temperatures can vary
spatially and temporally. During the 2010 and 2011 nesting seasons, this study estimated the hatchling sex ratio of leatherback sea turtles on Sandy Point National Wildlife Refuge (SPNWR), St. Croix, U.S. Virgin Islands. I measured sand temperatures from May- August and across the spatial range of leatherback nesting habitat. I spatially interpolated those temperatures to create maps that predicted temperatures for all nests incubating on SPWNR. Nest temperatures were also directly measured and compared with predicted nest temperatures to validate the prediction model. Sexes of dead-in-nest hatchlings and full term embryos were used to confirm the sex-temperature response. The model showed that microclimatic variation likely impacts the production of both sexes on SPNWR. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2013.
|
22 |
The distribution of predaceous fire ant species on important sea turtle nesting beaches in St. Croix, U.S. Virgin IslandsUnknown Date (has links)
The tropical fire ant, Solenopsis geminata is a New World species with a wide native
range including South America as well as several Caribbean islands. The red imported
fire ant, Solenopsis invicta is native to parts of South America. Both species are known
for preying on sea turtles’ eggs and hatchlings. The objectives of this thesis research
were to conduct follow-up and baseline ant species distribution surveys on four sea turtle
nesting beaches in St. Croix, U. S. Virgin Islands. Tuna baits were set out at beaches;
specimens were collected, frozen, preserved then identified. Results show that there was
a significant change in the fire ants’ distribution at Sandy Point National Wildlife Refuge
(SPNWR) while none were found at Jack Bay. Fire ants were also present on the other
two baseline surveyed nesting beaches. The displacement of S. geminata by S. invicta
was observed at SPNWR, which also was presumed by previous surveys. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
|
23 |
Factors affecting fish distribution in coastal habitats of the British Virgin IslandsGratwicke, Brian January 2004 (has links)
Few studies of tropical fish communities compare fish distributions across the full range of near-shore tropical marine habitats. As a result, our understanding of tropical marine fish communities is often biased towards habitats preferred by researchers. The distribution and habitat preferences of all 136 fish species occurring at 106 stations in three bays off Tortola in the British Virgin Islands were assessed. At a species level, habitat type was often the key factor influencing fish distribution. Of the 44 species occurring at more than 10 stations, 3 were sand specialists, 5 were strongly associated with mangroves, 7 were dependent on seagrass and algal beds and 14 were found only on the forereef. Eleven species were widely distributed both on the forereef and in bays, and 9 of them showed clear evidence of ontogenetic partitioning. The juveniles all preferred bay habitat types and moved onto the forereef as they approached sexual maturity. At a community level, five distinct fish assemblages were found. The assemblage types were classified according to their distribution: 1) forereef, 2) reef flat, 3) non-mangrove associated seagrass, 4) mangrove associated seagrass and 5) eutrophic areas. Forereef stations were the most species-rich with 24 species per station while eutrophic stations had the most depauperate communities with only 4 species per station. Variation in fish species richness at each station was largely explained by a simple habitat complexity index. It accounted for 70% of the variation in fish species richness and 21% of the variation in fish abundance. Rugosity and variety of growth forms were the most important predictors of species richness, but the height of the habitat architecture was the most useful predictor of fish abundance. Artificial reefs were constructed to test the effects of each habitat complexity variable experimentally. Increasing rugosity, variety of growth forms and percentage hard substrate increased the observed number of species but increasing the variety of hole-sizes, and height had no effect. The only complexity variable that had a significant effect on fish abundance was percentage hard substrate. In addition to the static substrate structure, long-spined sea urchins Diadema antillarum affected fish distribution because small fish shelter from predators in their spines. The urchins increase species richness and abundance in low complexity seagrass beds, but on artificial reefs, where shelter was not a limiting factor, the effect was less pronounced. Organic pollution is another factor that negatively affects the fish community by reducing fish species richness and abundance. Poor water quality often alters the natural habitat, confounding observations, but fish species richness was reduced in polluted areas even when artificial reefs were used as habitat controls. The applications of these findings to the management and conservation of fish in the British Virgin Islands are discussed.
|
24 |
Characterization of Shark Movements on a Mesophotic Caribbean Coral Reef and Temporal Association with Fish Spawning AggregationsPickard, Alexandria E. 01 November 2013 (has links)
Habitat use of mesophotic coral reefs by sharks is largely unknown. However, it is well established that mesophotic reefs are the site of spawning aggregations for many species of teleost fish. These aggregations represent seasonal concentrations of potential prey biomass that may influence the habitat use of predatory species such as large sharks. I employed acoustic monitoring to examine the movements of three shark species lemon shark (Negaprion brevirostris), tiger shark (Galeocerdo cuvier), and Caribbean reef shark (Carcharhinus perezi)] to determine 1) the comparative spatiotemporal patterns of mesophotic reef habitat use by the three shark species and 2) the spatiotemporal relationship between these sharks and grouper spawning aggregations at a fish spawning aggregation (FSA) site (Hind Bank and Grammanik Bank) along the southern reef shelf edge off St. Thomas, United States Virgin Islands (USVI). Tiger and lemon sharks were detected across nearly the entire acoustic array, which spanned ~ 1060 km2. When present, Caribbean reef sharks used a much smaller activity space, composed exclusively of mesophotic reef habitat located within FSA sites. Individuals from all three species were typically detected for stretches of several consecutive days, while periods without detections usually lasted less than one week. Lemon sharks were present at the FSA site more often during the grouper spawning season (Dec-May) than the non-spawning season (Jun-Nov), but showed no preference toward specific areas within the FSA site, which varied by location and grouper species composition. In contrast, there was no relationship between the presence of tiger and Caribbean reef sharks at the FSA site and the grouper spawning season. My results suggest that despite different habitat use patterns and varying degrees of fidelity, this mesophotic reef serves as an important habitat to all three shark species.
|
25 |
Health Disparities During the Covid-19 Pandemic in the U.S. TerritoriesMercado, Brook Lyn M. January 2022 (has links)
No description available.
|
26 |
Remote Sensing of Water Quality Parameters Influencing Coral Reef Health, U.S. Virgin IslandsSchlaerth, Hannah L. 11 May 2018 (has links)
No description available.
|
27 |
Komparace legislativy a exekutivy nezačleněných území USA / Comparison of legislative and executive branches in the US unincorporated territoriesTománek, Michal January 2020 (has links)
This Comparison of legislative and executive branches in the U.S. unincorporated territories thesis deals with political systems in unincorporated American territories - Puerto Rico, U.S. Virgin Islands, Guam, Commonwealth of Northern Mariana Islands and American Samoa. Today these territories stand as an integral part of the USA, but they do not hold federal state status. This study focuses on political systems of the individual territories, specifically on their legislative and executive bodies. It also explores relationships these territories have with the continental U.S., their status within American political system and it outlines genesis of autonomous government institutions of these territories. Concurrently, this thesis also elaborates on problem areas stemming from for example dual citizenship and citizens of these territories not being able to participate in presidential elections. This work comprises of five case studies that focus on political institutions of the individual territories. The main contribution of this study lies in the comparison work. In comparative analysis of the executive bodies and analysis of the extent of governors' authority within individual territories, and in the comparison with federal states. It also provides comparative analysis of legislative bodies of...
|
28 |
Global comparison of hedge fund regulationsStoll-Davey, Camille January 2008 (has links)
The regulation of hedge funds has been at the centre of a global policy debate for much of the past decade. Several factors feature in this debate including the magnitude of current global investments in hedge funds and the potential of hedge funds to both generate wealth and destabilise financial markets. The first part of the thesis describes the nature of hedge funds and locates the work in relation to four elements in existing theory including regulatory competition theory, the concept of differential mobility as identified by Musgrave, Kane’s concept of the regulatory dialectic between regulators and regulatees, and the concept of unique sets of trust and confidence factors that individual jurisdictions convey to the market. It also identifies a series of questions that de-limit the scope of the present work. These include whether there is evidence that regulatory competition occurs in the context of the provision of domicile for hedge funds, what are the factors which account for the current global distribution of hedge fund domicile, what latitude for regulatory competition is available to jurisdictions competing to provide the domicile for hedge funds, how is such latitude shaped by factors intrinsic and extrinsic to the competing jurisdictions, and why do the more powerful onshore jurisdictions competing to provide the domicile for hedge funds not shut down their smaller and weaker competitors? The second part of the thesis examines the regulatory environment for hedge funds in three so-called offshore jurisdictions, specifically the Cayman Islands, Bermuda and the British Virgin Islands, as well as two onshore jurisdictions, specifically the United Kingdom and the United States. The final section presents a series of conclusions and their implications for both regulatory competition theory and policy.
|
Page generated in 0.0619 seconds