Benthic Habitat Characterization and Habitat Use of Endangered Sea Turtles in Marine Protected Areas of the Greater Everglades Active
USGS assesses how federally endangered sea turtles use the habitat in and around a no-take area in the Dry Tortugas National Park.
The Science Issue and Relevance: The introduction of marine protected areas (MPAs) in which human use is highly regulated has become a priority management tool for at-risk coral reef habitats. The effectiveness of MPAs may be heavily dependent upon reserve factors such as size, placement, or location, enforcement of protected area boundaries, as well as whether adequate protection for vulnerable life stages of key species is provided in protected habitats. In Dry Tortugas National Park (DRTO), several MPAs have been established to protect natural and fisheries resources and associated coral reef habitats. We assess use of habitat in and around no-take areas of the Research Natural Area (RNA) by several species of federally endangered sea turtles (i.e., green turtles, Chelonia mydas; hawksbills, Eretmochelys imbricata; and loggerheads, Caretta caretta).
Methodology for Addressing the Issue: We have examined movement of key species across acoustically-monitored RNA boundaries. We quantitatively determine patterns of endangered sea turtle habitat use inside and outside the RNA by instrumenting turtles with both acoustic and satellite tags. We have also integrated USGS Coral Reef Project Scientist Dave Zawada’s high-resolution benthic mapping project to characterize benthic cover in areas where turtles are concentrating or repeatedly visiting. This coverage is a novel use of the Along-Track-Reef-Imaging-System (ATRIS), and a component of sea turtle habitat use studies that has been lacking to date. In 2014, we initiated satellite tagging of nesting loggerhead turtles in Everglades National Park (ENP). Further, by also including a molecular genetic component in our project, we are developing an understanding of the linkages and connections among endangered sea turtles using DRTO, ENP, and potentially other protected areas in the U. S. (i.e., Florida Keys National Marine Sanctuary [FKNMS]) and other countries. Such information is necessary for overall sea turtle population restoration and recovery efforts.
Future Steps: Since 2008 we have captured and marked 287 individual marine turtles in DRTO (178 green turtles, 100 loggerheads, nine hawksbills) and satellite-tagged over 100 turtles, see http://www.seaturtle.org/tracking/?project_id=402. By analyzing this tracking data, we have been able to delineate core-use areas and migration paths for all three species of turtles tagged. We have also successfully mapped >85 square kilometers of benthic habitat and have obtained 108,075 turtle detections on acoustic receivers throughout DRTO, which allows for fine-scale habitat-use determination. Since 2014 we have captured, marked and satellite-tagged seven loggerhead turtles in ENP. Future efforts and FY2016 fieldwork will include the continuation of satellite tagging and tracking at DRTO and ENP, increasing sample sizes, estimating survival rates, and implementing new tools to understand very fine scale turtle movement patterns, such as accelerometers.
Additional Related Project(s) and Product(s):
Detailed Seafloor Mapping to Enhance Marine-Resource Management (D. Zawada).
Hart KM, White CF, Iverson AR, Whitney N (Submitted) Trading shallow safety for deep sleep: juvenile green turtles risk increased predation for better rest as they grow.
Below are publications associated with this project.
Bahamas connection: residence areas selected by breeding female loggerheads tagged in Dry Tortugas National Park, USA
Breeding loggerhead marine turtles Caretta caretta in Dry Tortugas National Park, USA, show high fidelity to diverse habitats near nesting beaches
Determining origin in a migratory marine vertebrate: a novel method to integrate stable isotopes and satellite tracking
Genetic structure of Florida green turtle rookeries as indicated by mitochondrial DNA control region sequences
Temporal, spatial, and body size effects on growth rates of loggerhead sea turtles (Caretta caretta) in the Northwest Atlantic
Habitat use of breeding green turtles Chelonia mydas tagged in Dry Tortugas National Park: Making use of local and regional MPAs
Home range, habitat use, and migrations of hawksbill turtles tracked from Dry Tortugas National Park, Florida, USA
Inter-nesting habitat-use patterns of loggerhead sea turtles: Enhancing satellite tracking with benthic mapping
- Overview
USGS assesses how federally endangered sea turtles use the habitat in and around a no-take area in the Dry Tortugas National Park.
The Science Issue and Relevance: The introduction of marine protected areas (MPAs) in which human use is highly regulated has become a priority management tool for at-risk coral reef habitats. The effectiveness of MPAs may be heavily dependent upon reserve factors such as size, placement, or location, enforcement of protected area boundaries, as well as whether adequate protection for vulnerable life stages of key species is provided in protected habitats. In Dry Tortugas National Park (DRTO), several MPAs have been established to protect natural and fisheries resources and associated coral reef habitats. We assess use of habitat in and around no-take areas of the Research Natural Area (RNA) by several species of federally endangered sea turtles (i.e., green turtles, Chelonia mydas; hawksbills, Eretmochelys imbricata; and loggerheads, Caretta caretta).
Methodology for Addressing the Issue: We have examined movement of key species across acoustically-monitored RNA boundaries. We quantitatively determine patterns of endangered sea turtle habitat use inside and outside the RNA by instrumenting turtles with both acoustic and satellite tags. We have also integrated USGS Coral Reef Project Scientist Dave Zawada’s high-resolution benthic mapping project to characterize benthic cover in areas where turtles are concentrating or repeatedly visiting. This coverage is a novel use of the Along-Track-Reef-Imaging-System (ATRIS), and a component of sea turtle habitat use studies that has been lacking to date. In 2014, we initiated satellite tagging of nesting loggerhead turtles in Everglades National Park (ENP). Further, by also including a molecular genetic component in our project, we are developing an understanding of the linkages and connections among endangered sea turtles using DRTO, ENP, and potentially other protected areas in the U. S. (i.e., Florida Keys National Marine Sanctuary [FKNMS]) and other countries. Such information is necessary for overall sea turtle population restoration and recovery efforts.
Future Steps: Since 2008 we have captured and marked 287 individual marine turtles in DRTO (178 green turtles, 100 loggerheads, nine hawksbills) and satellite-tagged over 100 turtles, see http://www.seaturtle.org/tracking/?project_id=402. By analyzing this tracking data, we have been able to delineate core-use areas and migration paths for all three species of turtles tagged. We have also successfully mapped >85 square kilometers of benthic habitat and have obtained 108,075 turtle detections on acoustic receivers throughout DRTO, which allows for fine-scale habitat-use determination. Since 2014 we have captured, marked and satellite-tagged seven loggerhead turtles in ENP. Future efforts and FY2016 fieldwork will include the continuation of satellite tagging and tracking at DRTO and ENP, increasing sample sizes, estimating survival rates, and implementing new tools to understand very fine scale turtle movement patterns, such as accelerometers.
Additional Related Project(s) and Product(s):
Detailed Seafloor Mapping to Enhance Marine-Resource Management (D. Zawada).
Hart KM, White CF, Iverson AR, Whitney N (Submitted) Trading shallow safety for deep sleep: juvenile green turtles risk increased predation for better rest as they grow.
- Publications
Below are publications associated with this project.
Bahamas connection: residence areas selected by breeding female loggerheads tagged in Dry Tortugas National Park, USA
Background Delineation of home ranges, residence and foraging areas, and migration corridors is important for understanding the habitat needs for a given species. Recently, many population segments of Northwest Atlantic loggerhead sea turtles (Caretta caretta) were designated as endangered or threatened; the smallest subpopulation is in the Dry Tortugas. Foraging and residence areas for this subpoAuthorsKristen M. Hart, Autumn R. Sartain-Iverson, Ikuko FujisakiBreeding loggerhead marine turtles Caretta caretta in Dry Tortugas National Park, USA, show high fidelity to diverse habitats near nesting beaches
We used satellite telemetry to identify in-water habitat used by individuals in the smallest North-west Atlantic subpopulation of adult nesting loggerhead turtles Caretta caretta during the breeding season. During 2010, 2011 and 2012 breeding periods, a total of 20 adult females used habitats proximal to nesting beaches with various levels of protection within Dry Tortugas National Park. We then uAuthorsKristen M. Hart, David G. Zawada, Autumn R. Sartain-Iverson, Ikuko FujisakiDetermining origin in a migratory marine vertebrate: a novel method to integrate stable isotopes and satellite tracking
Stable isotope analysis is a useful tool to track animal movements in both terrestrial and marine environments. These intrinsic markers are assimilated through the diet and may exhibit spatial gradients as a result of biogeochemical processes at the base of the food web. In the marine environment, maps to predict the spatial distribution of stable isotopes are limited, and thus determining geograpAuthorsHannah B. Vander Zanden, Anton D. Tucker, Kristen M. Hart, Margaret M. Lamont, Ikuko Fujisaki, David S. Addison, Katherine L. Mansfield, Katrina F. Phillips, Michael B. Wunder, Gabriel J. Bowen, Mariela Pajuelo, Alan B. Bolten, Karen A. BjorndalGenetic structure of Florida green turtle rookeries as indicated by mitochondrial DNA control region sequences
Green turtle (Chelonia mydas) nesting has increased dramatically in Florida over the past two decades, ranking the Florida nesting aggregation among the largest in the Greater Caribbean region. Individual beaches that comprise several hundred kilometers of Florida’s east coast and Keys support tens to thousands of nests annually. These beaches encompass natural to highly developed habitats, and thAuthorsBrian M. Shamblin, Dean A. Bagley, Llewellyn M. Ehrhart, Nicole A. Desjardin, R. Erik Martin, Kristen M. Hart, Eugenia Naro-Maciel, Kirt Rusenko, John C. Stiner, Debra Sobel, Chris Johnson, Thomas Wilmers, Laura J. Wright, Campbell J. NairnTemporal, spatial, and body size effects on growth rates of loggerhead sea turtles (Caretta caretta) in the Northwest Atlantic
In response to a call from the US National Research Council for research programs to combine their data to improve sea turtle population assessments, we analyzed somatic growth data for Northwest Atlantic (NWA) loggerhead sea turtles (Caretta caretta) from 10 research programs. We assessed growth dynamics over wide ranges of geography (9–33°N latitude), time (1978–2012), and body size (35.4–103.3AuthorsKaren A. Bjorndal, Barbara A. Schroeder, Allen M. Foley, Blair E. Witherington, Michael Bresette, David Clark, Richard M. Herren, Michael D. Arendt, Jeffrey R. Schmid, Anne B. Meylan, Peter A. Meylan, Jane A. Provancha, Kristen M. Hart, Margaret M. Lamont, Raymond R. Carthy, Alan B. BoltenHabitat use of breeding green turtles Chelonia mydas tagged in Dry Tortugas National Park: Making use of local and regional MPAs
Use of existing marine protected areas (MPAs) by far-ranging marine turtles can be determined using satellite telemetry. Because of a lack of information on MPA use by marine turtles in the Gulf of Mexico, we used satellite transmitters in 2010 and 2011 to track movements of 11 adult female breeding green turtles (Chelonia mydas) tagged in Dry Tortugas National Park (DRTO), in the Gulf of Mexico,AuthorsKristen Hart, David G. Zawada, Ikuko Fujisaki, Barbara H. LidzHome range, habitat use, and migrations of hawksbill turtles tracked from Dry Tortugas National Park, Florida, USA
To determine habitat-use patterns of sub-adult hawksbills Eretmochelys imbricata, we conducted satellite- and acoustic-tracking of 3 turtles captured in August 2008 within Dry Tortugas National Park (DRTO), south Florida, USA, in the Gulf of Mexico; turtles ranged in size from 51.9 to 69.8 cm straight carapace length. After 263, 699, and 655 d of residence in the park, turtles migrated out of theAuthorsKristen M. Hart, Autumn R. Sartain-Iverson, Ikuko Fujisaki, Harold L. Pratt, Danielle Morley, Michael W. FeeleyInter-nesting habitat-use patterns of loggerhead sea turtles: Enhancing satellite tracking with benthic mapping
The loggerhead sea turtle Caretta caretta faces declining nest numbers and bycatches from commercial longline fishing in the southeastern USA. Understanding spatial and temporal habitat-use patterns of these turtles, especially reproductive females in the neritic zone, is critical for guiding management decisions. To assess marine turtle habitat use within the Dry Tortugas National Park (DRTO), weAuthorsKristen M. Hart, David G. Zawada, Ikuko Fujisaki, Barbara H. Lidz