Internesting Movements of Loggerhead (Caretta caretta) Sea Turtles in Virginia, USA

Virginia is the northern most nesting region regularly utilized by loggerhead sea turtles (Caretta caretta) along the eastern coast of the United States. Along the southern shoreline of Virginia, between two and ten nests have been recorded annually since 1989 within Back Bay National Wildlife Refuge and False Cape State Park. Since 1992, the Virginia Institute of Marine Science (VIMS) has attached eight satellite transmitters to nesting loggerhead sea turtles in order to monitor their interesting movements and falVwinter migrations. VIMS has tracked the same nesting loggerhead three separate times during the 1993, 1995 and 1997 nesting seasons. This turtle has been observed to migrate into the Delaware Bay and Chesapeake Bay between nesting events and prior to her fall migrations. This project has demonstrated that nesting loggerhead sea turtles return to Virginia over subsequent seasons to nest, and utilize the Chesapeake and Delaware Bays as internesting and post-nesting habitat. Late season nesters tracked by VIMS have migrated south after their last recorded Virginia nesting event and have traveled along the coasts of North and South Carolina, in two cases establishing fall residency off the Carolinas. Three turtles have been tracked as far south as eastern Florida, with two entering the Gulf of Mexico before satellite transmissions ceased. The tracking data generated by this project suggest that the adult turtles utilizing Virginia as nesting habitat preferentially utilize either the orth Atlantic region or South Atlantic region as over-wintering habitat. Temperature ranges within which tagged turtles have remained range between 13° and 31 ° C. Three tagged turtles have remained in Virginia\u27s waters until sea surface temperatures dropped to between 13° and 16° C before migrating south

Visual Acuity of Juvenile Loggerhead Sea Turtles (Caretta caretta): A Behavioral Approach

Studies focusing on the visual cues sea turtles use to orient between the nesting site and the sea indicate that sea turtles use diffuse images for orientation and are highly myopic on land. The visual environment encountered by sea turtles, however, is very different in water than on land. In this study, operant conditioning techniques were used to explore the visual acuity of juvenile loggerhead sea turtles (Caretta caretta) in the marine environment. Turtles were trained, in a tank setting, to distinguish between a 45 mm striped panel and 50% gray panel by using squid as a food reward. Though the pace of training was limited by our guidelines for holding these animals in captivity and the amount of food we could give each animal in a week, all turtles were trained in under a month. Once training was achieved, the stripes were reduced in size (stripe width ranging from 45.0 – 0.035 mm) until the turtle chose the striped panel over the 50% gray panel based on chance; this level of choice was designated as threshold. Mean acuity threshold level for all turtles tested was found to be 0.078 (visual angle of 12.89 minutes of arc). These results are similar to those of other marine species and indicate that loggerhead sea turtles use distinct visual cues in the aquatic environment

Highly migratory shark fisheries research by the National Shark Research Consortium (NSRC), 2002-2007

The National Shark Research Consortium (NSRC) includes the Center for Shark Research at Mote Marine Laboratory, the Pacific Shark Research Center at Moss Landing Marine Laboratories, the Shark Research Program at the Virginia Institute of Marine Science, and the Florida Program for Shark Research at the University of Florida. The consortium objectives include shark-related research in the Gulf of Mexico and along the Atlantic and Pacific coasts of the U.S., education and scientific cooperation

Spatiotemporal Overlap Of Spiny Dogfish (Squalus Acanthias) And Commercial Fisheries In The Northeast Us Shelf Large Marine Ecosystem

Commercial fishermen have argued that localized concentrations of spiny dogfish (Squalus acanthias) in the northeast U.S. shelf large marine ecosystem (NES LME) have impeded their fishing operations when monitoring surveys estimated lower relative abundances. Fishery-dependent and -independent data were analyzed simultaneously to examine whether increased spatial overlap between spiny dogfish and commercial fisheries may explain high catches of this species on fishing grounds. Spatial overlap was quantified between spiny dogfish distribution and commercial fisheries from 1989 to 2009 during autumn and spring in the NES LME. Combined, the sink gillnet (SGN) and otter trawl (OT) fisheries accounted for the majority of spiny dogfish catch (autumn: 85%; spring: 92%), either retained (SGN) or discarded (OT). Centers of spiny dogfish abundance illustrated spatial differences in local density within the NES LME and revealed seasonal differences in spiny dogfish density. Recent increases in spatial overlap indicate that a growing portion of the spiny dogfish stock was available to each fishery over the time series. Availability, estimated as the percentage of spiny dogfish present on fishing grounds, also increased and was generally higher during autumn than spring. Abundance of mature (total length.80 cm) female spiny dogfish was significantly related to availability, but trends were variable between fisheries and seasons. Although recent increases in abundance indicate recovery, research regarding the mechanisms behind these changes may help explain why abundance in the NES LME appears highly variable

Intraspecific Variation in Vertical Habitat Use by Tiger Sharks (Galeocerdo cuvier) in the Western North Atlantic

Tiger sharks (Galeocerdo cuvier) are a wide ranging, potentially keystone predator species that display a variety of horizontal movement patterns, making use of coastal and pelagic waters. Far less, however, is known about their vertical movements and use of the water column. We used pop-up satellite archival tags with two data sampling rates (high rate and standard rate tags) to investigate the vertical habitat use and diving behavior of tiger sharks tagged on the Puerto Rico–Virgin Islands platform and off Bermuda between 2008 and 2009. Useable data were received from nine of 14 sharks tagged, tracked over a total of 529 days. Sharks spent the majority of their time making yo-yo dives within the upper 50 m of the water column and considerable time within the upper 5 m of the water column. As a result, sharks typically occupied a narrow daily temperature range (~2°C). Dives to greater than 200 m were common, and all sharks made dives to at least 250 m, with one shark reaching a depth of 828 m. Despite some similarities among individuals, a great deal of intraspecific variability in vertical habit use was observed. Four distinct depth distributions that were not related to tagging location, horizontal movements, sex, or size were detected. In addition, similar depth distributions did not necessitate similar dive patterns among sharks. Recognition of intraspecific variability in habitat use of top predators can be crucial for effective management of these species and for understanding their influence on ecosystem dynamics

Civil Liberties and Volunteering in Six Former Soviet Union Countries

To contribute to the debate as to whether volunteering is an outcome of democratization rather than a driver of it, we analyze how divergent democratization pathways in six countries of the former Soviet Union have led to varied levels of volunteering. Using data from the European Values Study, we find that Latvia, Lithuania, and Estonia—which followed a Europeanization path—have high and increasing levels of civil liberties and volunteering. In Russia and Belarus, following a pre-emption path, civil liberties have remained low and volunteering has declined. Surprisingly, despite the Orange Revolution and increased civil liberties, volunteering rates in Ukraine have also declined. The case of Ukraine indicates that the freedom to participate is not always taken up by citizens. Our findings suggest it is not volunteering that brings civil liberties, but rather that increased civil liberties lead to higher levels of volunteerin

Spent fuel treatment and mineral waste form development at Argonne National Laboratory-West

At Argonne National Laboratory-West (ANL-West) there are several thousand kilograms of metallic spent nuclear fuel containing bond sodium. This fuel will be treated in the Fuel Conditioning Facility (FCF) at ANL-West to produce stable waste forms for storage and disposal. Both mineral and metal high-level waste forms will be produced. The mineral waste form will contain the active metal fission products and the transuranics. Cold small-scale waste form testing has been on-going at Argonne in Illinois. Large-scale testing is commencing at ANL-West

Monitorial citizens or civic omnivores? Repertoires of civic participation among university students

In present-day societies, the extent to which young people still participate in civic life is an important matter of concern. The claim of a generational "decline" in civic engagement has been contested, and interchanged with the notion of a "replacement" of traditional engagement by new types of participation, and the emergence of the "monitorial citizen" who participates in more individualized ways. Concurrently, this study explored the assumption of a "pluralization" of involvement, advancing a new concept: the "civic omnivore," characterized by an expanded civic repertoire. Drawing data from a sample of 1,493 Belgian and Dutch university students, we identify five repertoires of participation such as, disengaged students, classical volunteers, humanitarian citizens, monitorial citizens, and civic omnivores. Our findings support the pluralization thesis, by showing that young citizens are not exclusively engaged in new monitorial ways, yet also expand their civic repertoire by combining traditional and new forms in more complex ways

Compensatory Growth of the Sandbar Shark in the Western North Atlantic Including the Gulf of Mexico

The number of Sandbar Sharks Carcharhinus plumbeus in the western North Atlantic Ocean has experienced a drastic decline since the early 1980s, reaching a minimum during the early 1990s. Catch rates in the early 1990s were a mere 25% of those during the 1980s. According to several fishery-independent surveys, the low point in Sandbar Shark abundance followed a period of high exploitation. Growth models fit to age-length data collected from 1980 to 1983 and from 2001 to 2004 were compared to investigate potential changes in parameter estimates that might reveal compensatory responses in the Sandbar Shark population. Statistical differences were found between the model parameters for the two time periods, but the differences in growth rates were minimal. The parameters from the three-parameter von Bertalanffy growth model for female sharks during the 1980-1983 and 2000-2004 time periods were as follows: L = 188.4 and 178.3cm FL; k = 0.084 and 0.106; and t(0) = -4.097 and -3.41. For males the growth parameters were as follows: L = 164.63 and 173.66cm; k = 0.11 and 0.11; and t(0) = -3.62 and -3.33. The estimated age at 50% maturity for female Sandbar Sharks changed from 15years to 12.49years between the two time periods