Migration and habitat use of sea turtles in the Bahamas

Objectives: Evaluate movement and distribution patterns of sea turtles in our series of study sites in The Bahamas. This objective includes the questions of where do the turtles come from, how long are they resident in these sites, and where do they go when they leave. Collect data that will allow us to develop techniques to compare habitat quality and to serve as a foundation for studies of the role of green turtles in seagrass ecosystems. Evaluate models for estimating growth rates and carrying capacities for sea turtles based on our data from a long-term study of immature green turtles in the southern Bahamas. (Document has 7 pages.

Biology of pelagic sea turtles: effects of marine debris

Objectives: 1. Quantify the sub-lethal effect of debris ingestion (nutrient dilution) on nutrient gain 2. Model sub-lethal effects of debris ingestion on nutrient intake and growth 3. Evaluation of stress from entanglement on the loggerhead sea turtle 4. Movement patterns and behavior of pelagic-stage loggerheads in the eastern Atlantic 5. Document the genetic relationships of pelagic-stage loggerheads in the eastern Atlantic with rookeries in the southeast US (Document has 14 pages; lists publications resulting from research

A MODIS-Based Automated Flood Monitoring System for Southeast Asia

Flood disasters in Southeast Asia result in significant loss of life and economic damage. Remote sensing information systems designed to spatially and temporally monitor floods can help governments and international agencies formulate effective disaster response strategies during a flood and ultimately alleviate impacts to population, infrastructure, and agriculture. Recent destructive flood events in the Lower Mekong River Basin occurred in 2000, 2011, 16 2013, and 2016 (http://ffw.mrcmekong.org/historical_rec.htm, April 24, 2017). The large spatial distribution of flooded areas and lack of proper gauge data in the region makes accurate monitoring and assessment of impacts of floods difficult. Here, we discuss the utility of applying satellite-based Earth observations for improving flood inundation monitoring over the flood-prone Lower Mekong River Basin. We present a methodology for determining near real-time surface water extent associated with current and historic flood events by training surface water classifiers from 8-day, 250-meter Moderate-resolution Imaging Spectroradiometer (MODIS) data spanning the length of the MODIS satellite record. The Normalized Difference Vegetation Index (NDVI) signature of permanent water bodies (MOD44W; Carroll et al., 2009) is used to train surface water classifiers which are applied to a time period of interest. From this, an operational nowcast flood detection component is produced using twice daily imagery acquired at 3-hour latency which performs image compositing routines to minimize cloud cover. Case studies and accuracy assessments against radar-based observations for historic flood events are presented. The customizable system has been transferred to regional organizations and near real-time derived surface water products are made available through a web interface platform. Results highlight the potential of near real-time observation and impact assessment systems to serve as effective decision support tools for governments, international agencies, and disaster responders

Home range and habitat use by Kemp's Ridley turtles in West-Central Florida

The Kemp's ridley turtle (Lepidochelys kempii) is an endangered species whose recovery depends in part on the identification and protection of required habitats. We used radio and sonic telemetry on subadult Kemp's ridley turtles to investigate home-range size and habitat use in the coastal waters of west-central Florida from 1994 to 1996. We tracked 9 turtles during May-August up to 70 days after release and fou.ld they occupied 5-30 km2 foraging ranges. Compositional analyses indicated that turtles used rock outcroppings in their foraging ranges at a significantly higher proportion than expected. based on availability within the study area. Additionally. turtles used live bottom (e.g .• sessile invertebrates) and green macroalgae habitats significantly more than seagrass habitat. Similar studies are needed through'mt the Kemp's ridley turtles' range to investigate regional and stage-specific differences in habitat use. which can then be used to conserve important foraging areas

Evaluating trends in abundance of immature green turtles, Chelonia mydas, in the Greater Caribbean

Many long-lived marine species exhibit life history traits. that make them more vulnerable to overexploitation. Accurate population trend analysis is essential for development and assessment of management plans for these species. However, because many of these species disperse over large geographic areas, have life stages inaccessible to human surveyors, and/or undergo complex developmental migrations, data on trends in abundance are often available for only one stage of the population, usually breeding adults. The green turtle (Chelonia mydas) is one of these long-lived species for which population trends are based almost exclusively on either numbers of females that emerge to nest or numbers of nests deposited each year on geographically restricted beaches. In this study, we generated estimates of annual abundance for juvenile green turtles at two foraging grounds in the Bahamas based on long-term capture-mark-recapture (CMR) studies at Union Creek (24 years) and Conception Creek (13 years), using a two-stage approach. First, we estimated recapture probabilities from CMR data using the Cormack-Jolly-Seber models in the software program MARK; second, we estimated annual abundance of green turtles. at both study sites using the recapture probabilities in a Horvitz-Thompson type estimation procedure. Green turtle abundance did not change significantly in Conception Creek, but, in Union Creek, green turtle abundance had successive phases of significant increase, significant decrease, and stability. These changes in abundance resulted from changes in immigration, not survival or emigration. The trends in abundance on the foraging grounds did not conform to the significantly increasing trend for the major nesting population at Tortuguero, Costa Rica. This disparity highlights the challenges of assessing population-wide trends of green turtles and other long-lived species. The best approach for monitoring population trends may be a combination of (1) extensive surveys to provide data for large-scale trends in relative population abundance, and (2) intensive surveys, using CMR techniques, to estimate absolute abundance and evaluate the demographic processes' driving the trends

Estimates of survival probabilities for oceanic-stage loggerhead sea turtles (Caretta caretta) in the North Atlantic

Estimates of instantaneous mortality rates (Z) and annual apparent survival probabilities (Φ) were generated from catch-curve analyses for oceanic-stage juvenile loggerheads (Caretta caretta) in the waters of the Azores. Two age distributions were analyzed: the “total sample” of 1600 loggerheads primarily captured by sighting and dipnetting from a variety of vessels in the Azores between 1984 and 1995 and the “tuna sample” of 733 loggerheads (a subset of the total sample) captured by sighting and dipnetting from vessels in the commercial tuna fleet in the Azores between 1990 and 1992. Because loggerhead sea turtles begin to emigrate from oceanic to neritic habitats at age 7, the best estimates of instantaneous mortality rate (0.094) and annual survival probability (0.911) not confounded with permanent emigration were generated for age classes 2 through 6. These estimates must be interpreted with caution because of the assumptions upon which catch-curve analyses are based. However, these are the first directly derived estimates of mortality and survival probabilities for oceanic-stage sea turtles. Estimation of survival probabilities was identified as “an immediate and critical requirement” in 2000 by the Turtle Expert Working Group of the U.S. National Marine Fisheries Service

Pathogenic, Molecular, and Immunological Properties of a Virus Associated with Sea Turtle Fibropapillomatosis. Phase II : Viral Pathogenesis and Development of Diagnostic Assays

Research conducted under this RWO from July 1, 1997 through June 30, 2000 has provided important new information about the pathogenesis, virology, and immunology of marine turtle fibropapillomatosis. In particular, we have provided strong evidence for the association of a herpesvirus with fibropapillomatosis of the green turtle,Chelonia mydas, and the loggerhead turtle, Caretta caretta, in Florida. In addition we have provided new evidence for the absence of papillomaviruses from sea turtle fibropapillomas. Although unsuccessful, important new attempts were made to cultivate the FP-associated herpesvirus in vitro in collaboration with the National Wildlife Health Center. During this period of time, we completed publication of the first comprehensive description of the comparative pathology and pathogenesis of experimentally induced and spontaneous fibropapillomas of green turtles (Chelonia mydas). We initiated innovative studies on the persistence of a Chelonian herpesviruses in the marine environment demonstrating for the first time that the environmental survivability of Chelonian herpesviruses makes them real threats to marine turtle health. Finally, we explored development of a serological assay for FP using synthetic herpesvirus peptides and developed methodologies for detection of antibodies to LETV [Iung-eye-trachea virus] a disease-associated herpesvirus of the green turtle, Chelonia mydas.. This last initiative is ongoing and will further our efforts to develop specific immunological assays for the FP-associated herpesvirus and FP. (17 page document

Massively parallel density functional calculations for thousands of atoms: KKRnano

Applications of existing precise electronic-structure methods based on density functional theory are typically limited to the treatment of about 1000 inequivalent atoms, which leaves unresolved many open questions in material science, e. g., on complex defects, interfaces, dislocations, and nanostructures. KKRnano is a new massively parallel linear scaling all-electron density functional algorithm in the framework of the Korringa-Kohn-Rostoker (KKR) Green's-function method. We conceptualized, developed, and optimized KKRnano for large-scale applications of many thousands of atoms without compromising on the precision of a full-potential all-electron method, i.e., it is a method without any shape approximation of the charge density or potential. A key element of the new method is the iterative solution of the sparse linear Dyson equation, which we parallelized atom by atom, across energy points in the complex plane and for each spin degree of freedom using the message passing interface standard, followed by a lower-level OpenMP parallelization. This hybrid four-level parallelization allows for an efficient use of up to 100 000 processors on the latest generation of supercomputers. The iterative solution of the Dyson equation is significantly accelerated, employing preconditioning techniques making use of coarse-graining principles expressed in a block-circulant preconditioner. In this paper, we will describe the important elements of this new algorithm, focusing on the parallelization and preconditioning and showing scaling results for NiPd alloys up to 8192 atoms and 65 536 processors. At the end, we present an order-N algorithm for large-scale simulations of metallic systems, making use of the nearsighted principle of the KKR Green's-function approach by introducing a truncation of the electron scattering to a local cluster of atoms, the size of which is determined by the requested accuracy. By exploiting this algorithm, we show linear scaling calculations of more than 16 000 NiPd atoms

Impact of swordfish fisheries on sea turtles in the Azores.

The surface longline fishery around the Azores targets swordfish (Xiphias gladius). Bycatch from this fishery includes loggerhead sea turtles (Caretta caretta) and occasionally leatherback sea turtles (Dermochelys coriacea) that are either hooked or entangled in the lines. Hooks are generally set at depths of 15-50 m and baited with squid, mackerel, or sometimes with shark meat. The size classes of loggerhead sea turtles caught ranged from 41.3 to 65.4 cm curved carapace length and constitutes the largest size class of loggerheads occurring in the Azores. The impact on this size class affects the survival of the southeastern United States (SEUS) population of loggerheads because the loggerheads from the Azores are primarily from SEUS rookeries. For one commercial longline boat, we observed that the mean capture of turtles per 1000 hooks by month ranged between a minimum of 0.04 in May and a maximum of 0.79 in July with a weighted mean catch of 0.27. October and November also registered high catch rates. Of 60 turtles recorded, 54 were hooked in the mouth, 3 in the esophagus, 1 in the eye, 1 in the flipper, and one was undetermined. The turtles that were caught were physically strong, except one that was weak and another dead. Total capture of loggerhead sea turtles is estimated to be 4190 for the entire fleet fishing in the Exclusive Economic Zone of the Azores during the swordfish season (May to December) of 1998. We strongly recommend that observer programs be continued because capture rates may vary among years and among fishing boats