Benthic habitat characterization and habitat use of threatened and endangered sea turtles in Marine Protected Areas of the Greater Everglades

Project Investigator: Kristen Hart Project Personnel: Michael Cherkiss, Autumn Sartain, Ikuko Fujisaki Project Start Date: 2009 End Date: 2014 Recent Funding: (FY12) USGS CMG, (FY11) USGS CMG, (FY10) USGS CMG, (FY09) USGS CMG, (FY08) FWC Work Plans Related Links

Institution 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, and enforcement of protected area boundaries, as well as whether adequate protection for vulnerable life stages of key species is provided in protected habitats. In the Dry Tortugas National Park (DRTO), several MPAs have been established to protect natural and fisheries resources and associated coral reef habitats. This project proposes exploratory research to conduct a coupled habitat + species sampling project within and around the new Research Natural Area (RNA) of DRTO. Specifically, we will assess use of habitat in and around no-take areas of the RNA by several species of federally endangered sea turtles (i.e., greens (Chelonia mydas), hawksbills (Eretmochelys imbricata), and loggerheads (Caretta caretta). Green turtles are almost exclusively herbivorous, consuming seagrasses and algae, Hawksbills eat sponges, and thus are found associated with coral reefs and sponge cover, and Loggerheads feed on benthic invertebrates such as lobsters and crabs, as well as on fishery discards. Thus, these species are directly linked to key habitats of interest in DRTO and the surrounding waters. All three species are particularly suitable for immediate monitoring because they also nest on sandy upland areas of the Tortugas islands.

Specific objectives of the project are as follows:

• Monitor movement of turtles across and array of ~80 acoustic receivers deployed in and around the Dry Tortugas. We continue to quantitatively determine patterns of endangered sea turtle habitat use inside and outside the RNA by instrumenting turtles with both acoustic and satellite tags and analyzing data collected on our own receivers (N=7) and those of our partners (N=72). With acoustically-logged data, we are assessing the proportion of time each turtle spends inside the RNA, and with satellite-derived data, we are assessing the proportion of time each turtle spends outside the RNA or in areas not adjacent to acoustic receivers. Such information will be important for Park managers to assess appropriateness of current RNA boundaries for these high-profile endangered species.
• Integrate with USGS Coral Reef Ecosystem Studies (CREST) Project high-resolution benthic mapping project (led by PI Dave Zawada) 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.
• Include a molecular genetic component in our project to develop an understanding of the linkages and connections among endangered sea turtles using DRTO and potentially other protected areas in the U. S. (i.e., Everglades National Park (ENP), Florida Keys National Marine Sanctuary (FKNMS)) and other countries. Such information is necessary for overall sea turtle population restoration and recovery efforts.
• Include a diet component in our project to assess direct use of park resources by sea turtles.

Work Plans

• 2012

Related Links

• seaturtle.org