Historical Diet Analysis of Loggerhead (Caretta caretta) and Kemp\u27s Ridley (Lepidochelys kempi) Sea Turtles in Virginia

The Chesapeake Bay and coastal waters of Virginia, U.S.A. serve as foraging grounds for loggerhead (Caretta caretta) and Kemp’s ridley (Lepidochelys kempi) sea turtles from approximately May to October each year. Both loggerheads and Kemp’s ridleys are known to feed primarily on benthic invertebrates as juveniles and adults, but specific prey preferences vary between geographic regions. The Virginia Institute of Marine Science Sea Turtle Program has collected diet data and gut samples from stranded and incidentally caught sea turtles in Virginia since 1979. Examination of turtles that stranded in Virginia during the late 1970s and early 1980s indicated that loggerheads fed primarily on Atlantic horseshoe crab (Limulus polyphemus) and Kemp’s ridleys primarily on blue crab (Callinectes sapidus). During 1980 to 1994, 1997, and 2000 to 2002, 128 whole digestive tract samples and 41 partial gut samples were collected from loggerheads in Virginia. Diet information was noted on stranding datasheets for an additional 134 loggerheads from 1980 to 2002. Twenty-three whole samples and 10 partial samples were collected in Virginia from Kemp’s ridleys during 1987 to 1994 and 2000 to 2002, and data were available on an additional 26 ridleys from 1983 to 2002. Prey items in the samples were identified to the lowest possible taxonomic level, and dry weights and prey item counts were recorded. Results indicate a shift in loggerhead diet from predominantly horseshoe crab during the early to mid-1980s to predominantly blue crab during the late 1980s and early 1990s. Loggerhead diet in the mid-1990s and 2000 to 2002 was dominated by finfish, particularly menhaden (Brevoortia tyrannus) and croaker (Micropogonias undulatus). These diet shifts suggest that fishery-related declines in horseshoe crab and blue crab populations have caused loggerheads to instead forage on fish caught in nets or on discarded bycatch. A slight seasonal effect on diet was also detected, and the diet of juvenile loggerheads differed somewhat from that of the adults. The small Kemp’s ridley dataset suggests that blue crabs and spider crabs (Libinia spp.) were important components of ridley diet in Virginia during 1987 to 2002

An evaluation of sea turtle abundances, mortalities and fisheries interactions in the Chesapeake Bay, Virginia, 2001

Since 1979, the Virginia Institute of Marine Science (VIMS) Sea Turtle Research Program has served as the Commonwealth\u27s center for sea turtle research and conservation. The primary goal of this program is to assess and monitor sea turtle mortalities and population trends within the Chesapeake Bay and coastal waters of Virginia This has been accomplished through the management of a statewide sea turtle stranding network, aerial population research, behavioral studies using radio and satellite telemetry, arid age and growth research. A major migratory pathway for loggerhead (Carella caretta), Kemp\u27s ridley (Lepidochelys kempi) and leatherback (Dermochelys coriacea) sea turtles exists between Cape Hatteras, North Carolina and Virginia (Shoop et al, 1981; Shoop and Kenney, 1992; Keinath et al., 1994). Each year, between 200 and 400 sea turtle stranding deaths are recorded within Virginia\u27s waters. The vast majority of these strandings are juvenile loggerhead and Kemp\u27s ridley sea turtles. Historic stranding data show that 50.0% to 55.0% of the yearly turtle deaths occur in May and June when the turtles first enter the Bay (Lutcavage, 1981; Lutcavage and Musick, 1985; Keinath et al., 1987; Coles 1999). At the time when stranding counts are highest, mean water temperatures range between 18° and 22° C (Coles, 1999). Kemp\u27s ridleys also have an additional peak in strandings in the fall (October and November) when temperatures begin to drop (Lutcavage and Musick, 1985; Coles, 1999). Despite the VIMS Sea Turtle Research program\u27s conservation efforts, a significant number of sea turtle mortalities still occur each year within Virginia; state stranding counts have risen steadily over the last ten years. This increase may in part be due to either intensified fishing interactions, an increase in the sea turtle population. To address this problem, VIMS, under contract and supplemental funding from the National Marine Fisheries Service and Virginia\u27s Commercial Fishing Advisory Board, conducted aerial, surface and sub-surface fisheries surveys and aerial sea turtle population surveys in the Chesapeake Bay during the 2001 season

Informing research priorities for immature sea turtles through expert elicitation

Although sea turtles have received substantial focus worldwide, research on the immature life stages is still relatively limited. The latter is of particular importance, given that a large proportion of sea turtle populations comprises immature individuals. We set out to identify knowledge gaps and identify the main barriers hindering research in this field. We analyzed the perceptions of sea turtle experts through an online survey which gathered their opinions on the current state of affairs on immature sea turtle research, including species and regions in need of further study, priority research questions, and barriers that have interfered with the advancement of research. Our gap analysis indicates that studies on immature leatherback Dermochelys coriacea and hawksbill Eretmochelys imbricata turtles are lacking, as are studies on all species based in the Indian, South Pacific, and South Atlantic Oceans. Experts also perceived that studies in population ecology, namely on survivorship and demography, and habitat use/behavior, are needed to advance the state of knowledge on immature sea turtles. Our survey findings indicate the need for more inter-disciplinary research, collaborative efforts (eg data-sharing, joint field activities), and improved communication among researchers, funding bodies, stakeholders, and decision-makers

Network analysis of sea turtle movements and connectivity: A tool for conservation prioritization

Aim: Understanding the spatial ecology of animal movements is a critical element in conserving long-lived, highly mobile marine species. Analyzing networks developed from movements of six sea turtle species reveals marine connectivity and can help prioritize conservation efforts. Location: Global. Methods: We collated telemetry data from 1235 individuals and reviewed the literature to determine our dataset's representativeness. We used the telemetry data to develop spatial networks at different scales to examine areas, connections, and their geographic arrangement. We used graph theory metrics to compare networks across regions and species and to identify the role of important areas and connections. Results: Relevant literature and citations for data used in this study had very little overlap. Network analysis showed that sampling effort influenced network structure, and the arrangement of areas and connections for most networks was complex. However, important areas and connections identified by graph theory metrics can be different than areas of high data density. For the global network, marine regions in the Mediterranean had high closeness, while links with high betweenness among marine regions in the South Atlantic were critical for maintaining connectivity. Comparisons among species-specific networks showed that functional connectivity was related to movement ecology, resulting in networks composed of different areas and links. Main conclusions: Network analysis identified the structure and functional connectivity of the sea turtles in our sample at multiple scales. These network characteristics could help guide the coordination of management strategies for wide-ranging animals throughout their geographic extent. Most networks had complex structures that can contribute to greater robustness but may be more difficult to manage changes when compared to simpler forms. Area-based conservation measures would benefit sea turtle populations when directed toward areas with high closeness dominating network function. Promoting seascape connectivity of links with high betweenness would decrease network vulnerability.Fil: Kot, Connie Y.. University of Duke; Estados UnidosFil: Åkesson, Susanne. Lund University; SueciaFil: Alfaro Shigueto, Joanna. Universidad Cientifica del Sur; Perú. University of Exeter; Reino Unido. Pro Delphinus; PerúFil: Amorocho Llanos, Diego Fernando. Research Center for Environmental Management and Development; ColombiaFil: Antonopoulou, Marina. Emirates Wildlife Society-world Wide Fund For Nature; Emiratos Arabes UnidosFil: Balazs, George H.. Noaa Fisheries Service; Estados UnidosFil: Baverstock, Warren R.. The Aquarium and Dubai Turtle Rehabilitation Project; Emiratos Arabes UnidosFil: Blumenthal, Janice M.. Cayman Islands Government; Islas CaimánFil: Broderick, Annette C.. University of Exeter; Reino UnidoFil: Bruno, Ignacio. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Canbolat, Ali Fuat. Hacettepe Üniversitesi; Turquía. Ecological Research Society; TurquíaFil: Casale, Paolo. Università degli Studi di Pisa; ItaliaFil: Cejudo, Daniel. Universidad de Las Palmas de Gran Canaria; EspañaFil: Coyne, Michael S.. Seaturtle.org; Estados UnidosFil: Curtice, Corrie. University of Duke; Estados UnidosFil: DeLand, Sarah. University of Duke; Estados UnidosFil: DiMatteo, Andrew. CheloniData; Estados UnidosFil: Dodge, Kara. New England Aquarium; Estados UnidosFil: Dunn, Daniel C.. University of Queensland; Australia. The University of Queensland; Australia. University of Duke; Estados UnidosFil: Esteban, Nicole. Swansea University; Reino UnidoFil: Formia, Angela. Wildlife Conservation Society; Estados UnidosFil: Fuentes, Mariana M. P. B.. Florida State University; Estados UnidosFil: Fujioka, Ei. University of Duke; Estados UnidosFil: Garnier, Julie. The Zoological Society of London; Reino UnidoFil: Godfrey, Matthew H.. North Carolina Wildlife Resources Commission; Estados UnidosFil: Godley, Brendan J.. University of Exeter; Reino UnidoFil: González Carman, Victoria. Instituto National de Investigación y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Harrison, Autumn Lynn. Smithsonian Institution; Estados UnidosFil: Hart, Catherine E.. Grupo Tortuguero de las Californias A.C; México. Investigacion, Capacitacion y Soluciones Ambientales y Sociales A.C; MéxicoFil: Hawkes, Lucy A.. University of Exeter; Reino UnidoFil: Hays, Graeme C.. Deakin University; AustraliaFil: Hill, Nicholas. The Zoological Society of London; Reino UnidoFil: Hochscheid, Sandra. Stazione Zoologica Anton Dohrn; ItaliaFil: Kaska, Yakup. Dekamer—Sea Turtle Rescue Center; Turquía. Pamukkale Üniversitesi; TurquíaFil: Levy, Yaniv. University Of Haifa; Israel. Israel Nature And Parks Authority; IsraelFil: Ley Quiñónez, César P.. Instituto Politécnico Nacional; MéxicoFil: Lockhart, Gwen G.. Virginia Aquarium Marine Science Foundation; Estados Unidos. Naval Facilities Engineering Command; Estados UnidosFil: López-Mendilaharsu, Milagros. Projeto TAMAR; BrasilFil: Luschi, Paolo. Università degli Studi di Pisa; ItaliaFil: Mangel, Jeffrey C.. University of Exeter; Reino Unido. Pro Delphinus; PerúFil: Margaritoulis, Dimitris. Archelon; GreciaFil: Maxwell, Sara M.. University of Washington; Estados UnidosFil: McClellan, Catherine M.. University of Duke; Estados UnidosFil: Metcalfe, Kristian. University of Exeter; Reino UnidoFil: Mingozzi, Antonio. Università Della Calabria; ItaliaFil: Moncada, Felix G.. Centro de Investigaciones Pesqueras; CubaFil: Nichols, Wallace J.. California Academy Of Sciences; Estados Unidos. Center For The Blue Economy And International Environmental Policy Program; Estados UnidosFil: Parker, Denise M.. Noaa Fisheries Service; Estados UnidosFil: Patel, Samir H.. Coonamessett Farm Foundation; Estados Unidos. Drexel University; Estados UnidosFil: Pilcher, Nicolas J.. Marine Research Foundation; MalasiaFil: Poulin, Sarah. University of Duke; Estados UnidosFil: Read, Andrew J.. Duke University Marine Laboratory; Estados UnidosFil: Rees, ALan F.. University of Exeter; Reino Unido. Archelon; GreciaFil: Robinson, David P.. The Aquarium and Dubai Turtle Rehabilitation Project; Emiratos Arabes UnidosFil: Robinson, Nathan J.. Fundación Oceanogràfic; EspañaFil: Sandoval-Lugo, Alejandra G.. Instituto Politécnico Nacional; MéxicoFil: Schofield, Gail. Queen Mary University of London; Reino UnidoFil: Seminoff, Jeffrey A.. Noaa National Marine Fisheries Service Southwest Regional Office; Estados UnidosFil: Seney, Erin E.. University Of Central Florida; Estados UnidosFil: Snape, Robin T. E.. University of Exeter; Reino UnidoFil: Sözbilen, Dogan. Dekamer—sea Turtle Rescue Center; Turquía. Pamukkale University; TurquíaFil: Tomás, Jesús. Institut Cavanilles de Biodiversitat I Biologia Evolutiva; EspañaFil: Varo Cruz, Nuria. Universidad de Las Palmas de Gran Canaria; España. Ads Biodiversidad; España. Instituto Canario de Ciencias Marinas; EspañaFil: Wallace, Bryan P.. University of Duke; Estados Unidos. Ecolibrium, Inc.; Estados UnidosFil: Wildermann, Natalie E.. Texas A&M University; Estados UnidosFil: Witt, Matthew J.. University of Exeter; Reino UnidoFil: Zavala Norzagaray, Alan A.. Instituto politecnico nacional; MéxicoFil: Halpin, Patrick N.. University of Duke; Estados Unido

Diet Of Kemp\u27S Ridley Sea Turtles Incidentally Caught On Recreational Fishing Gear In The Northwestern Gulf Of Mexico

Twenty-one immature Kemp\u27s ridley sea turtles (Lepidochelys kempii) were collected following incidental capture or entanglement in recreational hook-and-line gear during 2005-2008 in Galveston County, Texas, United States. Turtles consumed primarily swimming crabs (common blue crab, Callinectes sapidus, and Callinectes spp.), walking crabs (calico box crab, Hepatus epheliticus; mottled purse crab, Persephona mediterranea; and hermit crabs), and polychaete worm tubes. Macroalgae (Sargassum spp.) was also consumed by nearly half of the sampled turtles, presumably incidentally and likely as benthic detritus. The upper Texas coast and local fishing piers provide diverse foraging opportunities for immature Kemp\u27s ridleys but also put the species at risk for interactions with human activities, including gear interactions and ingestion of anthropogenic debris

A Call For Evaluation Of The Contribution Made By Rescue, Resuscitation, Rehabilitation, And Release Translocations To Kemp’S Ridley Sea Turtle (Lepidochelys Kempii) Population Recovery

Kemp’s Ridley Sea Turtle (Lepidochelys kempii) conservation practices permitted by the National Marine Fisheries Service (NMFS) and U.S. Fish and Wildlife Service (USFWS), under authority of the U.S. Endangered Species Act of 1973, include translocations in which eggs or turtles are taken into captivity for various reasons and intervals, and turtles are later released into coastal waters of the Gulf of Mexico (GoM) or the Northwest Atlantic Ocean (NWAO). In 2013, the IUCN Species Survival Commission defined conservation translocation as the deliberate movement of organisms from one site for release in another, with the intention that it must yield a measurable conservation benefit at the levels of a population, species or ecosystem, and not only provide benefit to translocated individuals. Translocations of Kemp’s Ridley Sea Turtles that are found injured, ill, or otherwise debilitated, then rescued, resuscitated if necessary, rehabilitated, and released into the GoM or the NWAO have not been evaluated to determine whether they qualify as conservation translocations. We refer to them as rescue, resuscitation, rehabilitation, and release (i.e., RRRR) translocations. Captivity and human care, by altering behavioral and physiological fitness of RRRR translocated Kemp’s Ridley Sea Turtles, have the potential to influence post-release survival, growth, navigation, foraging, migration, maturation, natal beach homing, and reproduction. We recommend that NMFS and USFWS develop a plan for hypothesis-driven research and modeling aimed at determining if and how RRRR translocations contribute to Kemp’s Ridley Sea Turtle population recovery. Similar evaluations of RRRR translocations are also needed for other sea turtle species