Project Work Plan
Department of Interior USGS GE PES
Fiscal Year 2012 Study Work Plan
Study Title: Benthic habitat characterization and habitat use of threatened and endangered sea turtles in Marine Protected Areas of the Greater Everglades
Study Start Date: 1 September, 2009
Study End Date: 30 September, 2014
Web Sites: www.seaturtle.org
Duration: 5 years from FY2009 - 2013
Location (Subregions, Counties, Park or Refuge): Southern Florida Keys, Dry Tortugas National Park (Monroe County).
Funding Source: GE PES, Coastal and Marine Geology (CMG)
Other Complementary Funding Sources: USGS State Partnership Program (SPP), Fish and Wildlife Conservation Commission (FWCC), National Park Service (FY2008), USGS GE PES, USGS Coastal and Marine Geology (CMG) FY2009, FY2010, FY2011
Funding History: This project integrates with the USGS Coral Reef Ecosystem Studies (CREST) project funded by USGS Coastal and Marine Geology (CMG).
Principal Investigator: Kristen M. Hart
Study Personnel: Mike Cherkiss, Autumn Sartain (Jacobs contractor), Ikuko Fujisaki (University of Florida collaborator)
Supporting Organizations: US National Park Service
Associated / Linked Studies: High-resolution mapping of the Dry Tortugas (USGS PI Zawada)
Overview & Objective(s): 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.
Specific Relevance to Major Unanswered Questions and Information Needs Identified:
Data is lacking on the use of protected areas (MPAs) by endangered species. Despite detailed knowledge of general sea turtle nesting trends in DRTO (i.e., on Loggerhead and East Keys), little information has been available about in-water sea turtle use of natural resources. The southern and eastern boundaries of the RNA in DRTO were ringed with acoustic listening stations in summer 2008 (Fig. 1) through USGS SPP funding. We also deployed seven of our own receivers in 2009 in habitats frequented by sea turtles. By capturing and acoustically tagging endangered sea turtles from within and around the RNA, we are determining fine-scale patterns of sea turtle habitat use and movement patterns within and around the RNA. Because we are also attaching satellite tags to a subset of the acoustically-equipped turtles, we are determining the proportion of time these endangered turtles are spending in areas adjacent to the RNA (i.e., in other protected areas in DRTO or outside the Park). This project addresses the specific resource management information need regarding endangered species use of Park resources, and condition and location of those resources (i.e., seagrass, sponge, and hardbottom habitats, as well as nesting beaches). The significance and priority of the issue to the Park or the NPS is that such habitat in DRTO may serve as critical habitat for this endangered species. Such critical habitats must be considered in Recovery Plans for the species aimed at restoring sea turtle population numbers. In addition, with climate change scenarios, critical nesting beaches must be included in recovery plans and population restoration efforts. The condition of the nesting beaches in DRTO has been affected by invasive Australian pines (Casuarina equisetifolia), and a removal program in the mid 1990s failed to remove roots and stumps from Loggerhead Key. Thus, significant restoration of this important nesting beach remains an issue for both adults and hatchlings of these endangered marine turtle species.
Of the three overarching restoration questions laid out in the U.S. Department of the Interior Science Plan in Support of Ecosystem Restoration, Preservation, and Protection in South Florida, this project directly address two of these:
- What actions will restore, protect, and maintain natural resources on DOI lands in South Florida?
- What actions will recover South Florida's threatened and endangered species?
Additionally, since we have the opportunity to tag nesting female sea turtles using DRTO beaches, the U.S. Fish and Wildlife Service and the National Marine Fisheries Service will benefit form the information derived from the proposed tasks; essentially, the former has jurisdiction and responsibility for endangered sea turtles while they are on land, and the latter has jurisdiction and responsibility for them when they are in the water. Thus, this project not only benefits other DOI agency missions of the USGS, NPS, and USFWS, but also that of the Department of Commerce (DOC).
Using new technologies, this project is currently using state-of the art underwater acoustic and satellite technology to track movements of endangered sea turtles within and outside of the boundaries of DRTO. Activities proposed here relate to and complement one component of the joint USGS/State-FWC SPP fish proposal (funding to USGS McIvor in 2007, receiver deployment in May 2008) to deploy and utilize an acoustic array in the RNA. The goal of this already-funded joint SPP project is to examine the fine-scale movement patterns and core utilization areas of exploited fish species to determine the spatial adequacy of existing reserve boundaries. The SPP project and the project proposed here would make use of the same array of receivers. This project has added additional receivers in a specific habitats of interest in DRTO (i.e., in seagrass beds, adjacent to areas of dense sponge cover), not just along the boundary lines. The State-FWC will house the digital database of tag locations, and perform most data-downloading; we have been collaborating with their ongoing field and data processing efforts. Unlike the fish project, this turtle tracking project will contain an "outside the RNA" component by utilizing satellite data acquired from satellite tags deployed alongside acoustic tags on sea turtles; data derived from these satellite tags is already informing managers of turtle habitat use outside the RNA (i.e., in the Bahamas, off Mexico, off Sanibel and Naples, and throughout the Florida Keys):
|http://www.seaturtle.org/tracking/?project_id=402 [larger image]|
Such information is revealing whether the boundaries of the RNA should be adjusted in order to more adequately protect endangered turtles using specific benthic habitats for forage and upland habitats for nesting. The integrated Hart-Zawada project will rely on both USGS-GE PES and USGS Coastal and Marine Geology funding to conduct endangered sea turtle tracking in concert with high-resolution mapping and fine-scale benthic habitat characterization using the Along-Track-Reef-Imaging-System (ATRIS).
Summary of Progress:
Accomplishments To Date:
Since 2008 we have deployed N=51 satellite tags and N=69 acoustic tags and have successfully worked out capture methods both on land and in the water. We are beginning to recapture nesting female green and loggerhead turtles, as they often return to nest on their natal beaches every other year. Thus, we are beginning to shed light on the number of nesting females in the genetically-distinct DRTO loggerhead population.
We have published several key manuscripts:
Hart KM, Zawada DG, Fujisaki I, Lidz BH (2010) Inter-nesting habitat-use patterns of loggerhead sea turtles: Enhancing satellite tracking with benthic mapping. Aquatic Biology.11:77-90.
Hart KM (2010) Use of protected areas by threatened and endangered marine turtles in the Dry Tortugas Pg:12-13, In: Hallac, D and J. Hunt, editors. Implementing the Dry Tortugas National Park Research Natural Areas Science Plan: the 3-year report. South Florida Natural Resources Center, Everglades and Dry Tortugas National Parks, Homestead, FL, and the Florida Fish and Wildlife Conservation Commission, Tallahassee, FL. 37 pp.
We are publishing several more key manuscripts in 2012:
Hart KM, Lamont MM, Fujisaki I, Tucker AD, Carthy RR (2012) Common coastal foraging areas for loggerheads in the Gulf of Mexico: opportunities for marine conservation. Biological Conservation 145:185-194.
Hart KM, Sartain AR, Fujisaki I, Pratt HLJr, Morley D, Feeley MW (2012) Home range, habitat use and migrations of hawksbill turtles tracked from Dry Tortugas National Park, Florida, USA. Marine Ecology Progress Series 457:193-207, doi: 10.3354/meps09744
Hart KM, Fujisaki I, Sartain AR (2012) Chapter 5: Use of Dry Tortugas National Park by threatened and endangered marine turtles. Pp 28-33. In: Ziegler, T.A. and Hunt, J., editors. 2012. Implementing the Dry Tortugas National Park Research Natural Area Science Plan: The 5-Year Report 2012. South Florida Natural Resources Center, Everglades and Dry Tortugas National Parks, Homestead, FL, and the Florida Fish and Wildlife Conservation Commission, Tallahassee, FL. 63 pp.
During FY12, we will continue to conduct both nesting beach work and in-water turtle captures to increase the sample sizes of tagged/sampled individuals for all three species. We will specifically plan capture and tagging efforts to assess 1) whether reproductively mature female loggerheads nesting on Loggerhead Key utilize the same inter-nesting habitat (50% core use area) outside the RNA as that used by the seven loggerheads previously tagged on East Key; 2) where nesting green turtles from both East Key and Loggerhead Key spend their time in the inter-nesting interval (and whether this area is in the RNA); 3) where additional hawksbills may be found. We also expect to be able to determine through satellite tracking whether reproductive female green turtles nesting at DRTO are resident within the Park, or instead migrate elsewhere after the nesting season. We will continue to collaborate with the State FWCC biologists and Mote's Wes Pratt on acoustic data download and exchange and maintain the network of seven acoustic receivers that we deployed in 2009; we currently have three acoustic data-downloading trips planned each year for the next two years. We will continue catching juvenile greens (and hopefully more hawksbills) in the shallow flat around Bird/Long Key and refine growth rate estimates for these young turtles. Additionally, we will process all lavage samples, conduct isotope analysis, and conduct genetic analysis to determine stock structure for each species. We will continue to update information on residence times for turtles residing in and using DRTO. We will also continue to work with USGS PI Zawada to use ATRIS, a benthic habitat mapping and characterization tool, to plan mapping and habitat characterization efforts in turtle inter-nesting habitat and other turtle core use areas in the Park. The combined data sets will provide insight into (1) the effectiveness of the RNA for protecting threatened and endangered marine turtles and their requisite habitats, (2) the condition of those habitats (i.e., seagrass beds), and (3) the development of more effective decision-support tools to adaptively manage coral ecosystems.
Planned Products: Products that will result from this project include at least 3 major publications (two to share tracking data and one to present genetic analysis results, likely in Endangered Species Research, Marine Ecology Progress Series, and Conservation Genetics), as well as presentations at regional, national and international scientific conferences (i.e., Annual Sea Turtle Symposium). Also, annual and project end reports will be filed in compliance with USGS and NPS, State of Florida, and NMFS permit requirements. The public will be informed through www.seaturtle.org/tracking and USGS Soundwaves articles. Funding agencies and other interested parties may log in to the website daily to observe turtle locations and habitat use trends. As well, we will generate GIS layers of benthic habitat maps each year after Tortugas cruises. Maps will be made available to the USGS and NPS after processing, generally several months after a cruise. Hart will ensure transfer of key results on sea turtle habitat use patterns and genetic composition to NMFS for inclusion in Recovery Plans for green sea turtles.
Task 1: Benthic habitat
characterization and habitat use of threatened and endangered sea turtles in Marine
Protected Areas of the Greater Everglades
Task Funding: GE PES
Task Leaders: Kristen M. Hart
Task Status (proposed or active): Active
Task priority: High
Time Frame for Task 1: 2010-2013
Task Personnel: Mike Cherkiss (University of Florida), Autumn Sartain (Jacobs contractor), Ikuko Fujisaki (University of Florida)
Task Summary and Objectives: The purpose of this task is to capture and tag sea turtles in the Dry Tortugas National Park with standard PIT and flipper tags, as well as state-of-the-art acoustic and satellite tags. Capture sites will be on nesting beaches (i.e., Loggerhead Key, East Key) and in the water near Bush Key and Long Key as well as near Pulaski Light; capture sites will be both inside and outside the RNA. We will work-up each individual sea turtle to obtain diet and genetic samples, as well as morphometric information. Tracking efforts will involve downloading data from acoustic receivers several times a year as well as daily uploads of locations derived from satellite tags affixed to a proportion of each turtles for each species.
Work to be undertaken during the project and a description of the methods and procedures:
- Deploy and maintain acoustic receivers in areas of interest in DRTO (i.e., in seagrass beds in the northeast area of the Park and in shallow water near Long and Bush Keys, where sea turtle observations have been concentrated), both within and outside the RNA.
- Conduct fieldwork to capture and tag sea turtles from both nesting beaches and in-water feeding grounds. Outfit each large turtle with both an acoustic tag and a satellite tag; outfit each smaller turtle with either a satellite tag or an acoustic tag. Each turtle will be sampled for diet and genetics. We will apply internal PIT and external Inconel tags to all turtles captured, and take standard morphometric measurements and weight (if possible). Data will be used to determine (1) size class and condition (including fibropapillomatosis (FP) disease presence)) of green sea turtles using the RNA (because of the remoteness of DRTO, we hypothesize that FP will not be commonly seen on green turtles sampled in the RNA); (2) diet of green sea turtles using the RNA; (3) potential links to other sea turtle populations if some turtles are already tagged from other studies.
- Examine movement patterns of tagged turtles to determine residence times and habitat use relationships. In particular, we will quantify fine-scale movement patterns and core utilization areas of endangered sea turtles to determine the spatial habitat use patterns both inside and outside the RNA by using satellite and acoustic tracking technologies. We will characterize the habitat features that are utilized by these turtles by relating tracks derived from acoustic and satellite telemetry data to both static (i.e., bathymetry)) and dynamic (i.e., temperature, salinity, food resource location) features of the RNA. We will analyze location data to examine whether locations received were indicative of directed or nondirected (sedentary) movements and behaviors (i.e., by analyzing perceived swim speed, direction of travel, etc.). We will use the Satellite Tracking and Analysis tool (STAT) (Coyne and Godley 2005) available on www.seaturtle.org/tracking to manage satellite telemetry data and maximize the potential of these relatively expensive data. An extremely valuable aspect of STAT is its ability to automatically retrieve, parse, and store telemetry data from the Argos Satellite network. A suite of summary maps, tables, and graphs are updated each day, allowing investigators to easily check each of the tagged animals. STAT also provides an array of mapping, filtering, and export functions to facilitate data analysis, as well as access to bathymetry, sea surface temperature, chlorophyll, sea surface height, and ocean surface currents, thus allowing researchers to see turtle movement in the context of the local environment (Polovina et al. 2000; 2004). The centers of turtle activity will be analyzed using the Animal Movement™ extension for ARCVIEW 3.2 to give home ranges using kernel-based frequency distributions of locations. Home ranges will be compared to spatially explicit environmental data (e.g., distribution of continuous and discontinuous seagrass) based on available and created (through NOAA) GIS layers.
- Analyze location information to determine the spatial adequacy of existing reserve boundaries for these threatened and endangered marine turtle species. We will also compare satellite and acoustic data from the same turtle to determine consistency of location data derived from both remote tracking methods
- Characterize benthic habitats used by sea turtles in the Dry Tortugas. Bottom type will be identified and categorized using the USGS Along-Track-Reef-Imaging-System (ATRIS) in conjunction with USGS PI Dave Zawada (St. Pete), as well as other underwater digital photography and quadrat sampling.
- Work with USGS PI Zawada to examine benthic cover data collected using ATRIS in areas of interest (i.e., RNA boundary lines, turtle "hotspots"). Conduct additional in-water habitat characterization of soft bottom and hard bottom cover in the RNA, particularly in areas frequented by tagged sea turtles. We will use all data to determine whether the RNA serves as refuge for endangered species and how much critical habitat for green sea turtles lies within the boundaries of the RNA (and potentially other TER protected areas).
- Identify genetic diversity of sea turtles in the Dry Tortugas and compare it to other previously sampled sea turtles from other areas in south Florida and beyond. Each sea turtle will be sampled for genetics during the work-up procedure. Samples will be sent for analysis to Dr. Eugenia Naro-Maciel at the American Museum of Natural History (AMNH) in New York City, NY. By using previously developed molecular markers and analyzing mitochondrial DNA from each turtle to obtain genotypes, we can assess the likelihood that these turtles are all from the same or several different nesting beaches. This analysis will reveal genetic linkages to other sea turtle populations sampled elsewhere. We will analyze mitochondrial DNA control region sequences and nuclear microsatellite genotypes and compare data from DRTO turtles to sequences posted on GENBANK. The program ARLEQUIN version 3.01 (Excoffier et al. 2005) will be used to characterize genetic diversity, and to assess genetic structure through exact tests of population differentiation (Raymond and Rousset 1995). Bayesian clustering analyses implemented by STRUCTURE version 2.1 will be used to estimate connectivity revealed by microsatellite markers without assuming prior population definitions (Pritchard et al. 2000). In addition, the Mixed Stock Analysis (Pella and Milner 2001) method will be used to trace natal origins of these sea turtles.
Specific Task Products: We will present the results of sea turtle tracking and capture efforts in January 2010 at the National Park Service Workshop on the 5-year evaluation of the RNA in Homestead, FL, as well as in June 2012 at the Greater Everglades Ecosystem Restoration (GEER) meeting at the INTECOL conference in Orlando, FL. We will also present results of sea turtle tracking at the annual Sea Turtle Symposia and Southeast Regional meetings. We plan to submit several manuscripts on the results of the acoustic and satellite tracking, as well as two manuscripts on turtle habitat use + ATRIS benthic habitat characterization. Maps of turtle movement patterns will be available on www.seaturtle.org, and through USGS PIs. USGS-Hart will work with Naro-Maciel to synthesize results of genetic analysis for reports, presentations, and publications. We expect that one at least one peer-reviewed manuscript will result from the genetic analysis.
Coyne, M. S., and B. J. Godley. 2005. Satellite Tracking and Analysis Tool (STAT): an integrated system for archiving, analyzing and mapping animal tracking data. Marine Ecology Progress Series 301:1-7.
Excoffier, L. G. Laval, and S. Schneider. 2005. Arlequin version 3.0: An integrated software package for population genetics data analysis. Evolutionary Bioinformatics Online 1:47-50.
Fonseca, M.S., A.V. Uhrin, C.A. Currin, J.S. Burke, D.W. Field, C.A. Addison, L. L. Wood, G. A. Piniak, T. S. Viehman, and C. S. Bonn. 2006. Ongoing Monitoring of Tortugas Ecological Reserve: Assessing the Consequences of Reserve Designation. NOAA Technical Memorandum NOS NCCOS 22.
Franklin, E.C., J.S. Ault, S.G. Smith, J. Luo, G.A. Meester, G.A. Diaz, M. Chiappone, D.W. Swanson, S.L. Miller and J.A. Bohnsack. 2003. Benthic habitat mapping in the Tortugas region, Florida. Marine Geodesy 26:19-34.
Pella, J., and M. Masuda. 2001. Bayesian methods for analysis of stock mixtures from genetic characters. Fishery Bulletin 9:151-167.
Polovina, J. J., D. R. Kobayashi, D. M. Parker, M. P. Seki, and G. H. Balazs. 2000. Turtles on the edge: movement of loggerhead turtles (Caretta caretta) along oceanic fronts, spanning longline fishing grounds in the central North Pacific, 1997-1998. Fisheries Oceanography 9(1): 71-82.
Polovina, J. J., G. H. Balazs, E. A. Howell, D. M. Parker, M. P. Seki, and P. H. Dutton. 2004. Forage and migration habitat of loggerhead (Caretta caretta) and olive ridley (Lepidochelys olivacea) sea turtles in the central North Pacific Ocean. Fisheries Oceanography 13 (1): 36-51.
Pritchard J. K., M. Stephens, and P. Donnelly. 2000. Inference of population structure using multilocus genotype data. Genetics 155:945-959.
Raymond, M., and F. Rousset. 1995a. An exact test for population differentiation. Evolution 49:1280-1283.