Kristen Hart, Ph.D.
Ph.D., Ecology, Duke University, 2005
M.E.M. (Master's of Environmental Management), Coastal Environmental Management, Duke University, 1999
B.S., Boston College, Bachelor of Science, 1997
Kristen Hart is a research ecologist, focusing on population-level studies on the ecology of a broad array of herpetofauna and other wildlife in south Florida. She leads several research programs and collaborates closely with other USGS, university, and National Park Service scientists. She has built a program of USGS cyclic- and reimbursable funded research; major funding has been provided from the US Fish and Wildlife Service, the US Army Corps of Engineers, the USGS Priority Ecosystem Studies Program, the USGS Coastal and Marine Geology Program, and the National Park Service. She works with rare, threatened, endangered, and invasive species of reptiles including Diamondback terrapins, loggerhead sea turtles, green sea turtles, hawksbill sea turtles, crocodilians, and Burmese pythons. She is based in Davie, FL and has field sites in both Everglades and Dry Tortugas National Parks in South Florida, Bon Secour National Wildlife Refuge (Gulf Shores, AL), and Buck Island Reef National Monument (St. Croix, U.S. Virgin Islands).
Science and Products
The Bureau of Ocean Energy Management (BOEM) uses trawling to capture and relocate live sea turtles away from dredging locations to minimize the risk of turtle entrainment. These incidental turtle captures provide a unique opportunity to fill critical data gaps for difficult to capture life-stages of marine turtles.
Distribution and Density of Sea Turtles in the Gulf of Mexico (GOM): Gulf of Mexico Marine Assessment Program for Protected Species (GoMMAPPS)
The over-arching goal of GoMMAPPS is to collect broad-scale survey data for seabirds, marine mammals and sea turtles to determine distribution and abundance in the Gulf of Mexico.
Genetic Analysis of the Invasive Burmese Python to Aid Management and Population-Control Decision-Making
Invasive Burmese pythons threaten the success of Everglades restoration efforts. To assist with management and population control decision making, USGS scientists are implementing genetic studies to identify potential new entry pathways and to help quantify the size of the breeding population.
Population Biology and Ecology of Diamondback Terrapins in Mangrove Forested Ecosystems in the Greater Everglades
Long-term capture-recapture research in the Everglades National Park provides baseline information on the Diamondback Terrapin, a species that may be threatened by human disturbances.
Benthic Habitat Characterization and Habitat Use of Endangered Sea Turtles in Marine Protected Areas of the Greater Everglades
USGS assesses how federally endangered sea turtles use the habitat in and around a no-take area in the Dry Tortugas National Park.
Climate change may reduce the suitability of nesting and foraging habitat used by federally threatened and endangered species, like the Loggerhead sea turtle.
USGS researchers tag and track endangered and threatened sea turtles to inform adaptive management strategies in marine protected areas.
Ecology of and Control Strategies for Invasive Burmese Pythons (Python molurus bivitattus) in the Greater Everglades
Telemetry tracking of captured pythons reveals movement patterns of the invasive Burmese python in the Greater Everglades, information that managers can use to prioritize python control efforts.
Spatial Ecology of the American Crocodile (Crocodylus acutus) and American Alligator (Alligator mississippiensis) in the Greater Everglades
Satellite/GPS tags help USGS researchers understand the movements of American Alligators and American Crocodiles in the Greater Everglades.
Ecological regime shift drives declining growth rates of sea turtles throughout the West Atlantic
Somatic growth is an integrated, individual-based response to environmental conditions, especially in ectotherms. Growth dynamics of large, mobile animals are particularly useful as bio-indicators of environmental change at regional scales. We assembled growth rate data from throughout the West Atlantic for green turtles, Chelonia mydas, which are...Bjorndal, Karen A.; Bolten, Alan B.; Chaloupka, Milani; Saba, Vincent S.; Bellini, Cláudio; Marcovaldi, Maria A.G.; Santos, Armando J.B.; Bortolon, Luis Felipe Wurdig; Meylan, Anne B.; Meylan, Peter A.; Gray, Jennifer; Hardy, Robert; Brost, Beth; Bresette, Michael; Gorham, Jonathan C.; Connett, Stephen; Crouchley, Barbara Van Sciver; Dawson, Mike; Hayes, Deborah; Diez, Carlos E.; van Dam, Robert P.; Willis, Sue; Nava, Mabel; Hart, Kristen M.; Cherkiss, Michael S.; Crowder, Andrew; Pollock, Clayton; Hillis-Starr, Zandy; Muñoz Tenería, Fernando A.; Herrera-Pavón, Roberto; Labrada-Martagón, Vanessa; Lorences, Armando; Negrete-Philippe, Ana; Lamont, Margaret M.; Foley, Allen M.; Bailey, Rhonda; Carthy, Raymond R.; Scarpino, Russell; McMichael, Erin; Provancha, Jane A.; Brooks, Annabelle; Jardim, Adriana; López-Mendilaharsu, Milagros; González-Paredes, Daniel; Estrades, Andrés; Fallabrino, Alejandro; Martínez-Souza, Gustavo; Vélez-Rubio, Gabriela M.; Boulon, Ralf H.; Collazo, Jaime; Wershoven, Robert; Hernández, Vicente Guzmán; Stringell, Thomas B.; Sanghera, Amdeep; Richardson, Peter B.; Broderick, Annette C.; Phillips, Quinton; Calosso, Marta C.; Claydon, John A.B.; Metz, Tasha L.; Gordon, Amanda L.; Landry, Andre M.; Shaver, Donna J.; Blumenthal, Janice; Collyer, Lucy; Godley, Brendan J.; McGowan, Andrew; Witt, Matthew J.; Campbell, Cathi L.; Lagueux, Cynthia J.; Bethel, Thomas L.; Kenyon, Lory
Resident areas and migrations of female green turtles nesting at Buck Island Reef National Monument, St. Croix, U.S. Virgin Islands
Satellite tracking in marine turtle studies can reveal much about their spatial use of breeding areas, migration zones, and foraging sites. We assessed spatial habitat-use patterns of 10 adult female green turtles (Chelonia mydas) nesting at Buck Island Reef National Monument, U.S. Virgin Islands (BIRNM) from 2011 – 2014. Turtles ranged in size...Hart, Kristen M.; Iverson, Autumn; Benscoter, Allison M.; Fujisaki, Ikuko; Cherkiss, Michael S.; Pollock, Clayton; Lundgren, Ian; Hillis-Starr, Zandy
Are we working towards global research priorities for management and conservation of sea turtles?
In 2010, an international group of 35 sea turtle researchers refined an initial list of more than 200 research questions into 20 metaquestions that were considered key for management and conservation of sea turtles. These were classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies...Rees, A.F.; Alfaro-Shigueto, J.; Barata, P.C.R.; Bjorndal, K.A.; Bolten, A.B.; Bourjea, J.; Broderick, A.C.; Campbell, L.M.; Cardona, L.; Carreras, C.; Casale, P.; Ceriani, S.A.; Dutton, P.H.; Eguchi, T.; Formia, A.; Fuentes, M.M.P.B.; Fuller, W.J.; Girondot, M.; Godfrey, M.H.; Hamann, M.; Hart, Kristen M.; Hays, G.C.; Hochscheid, S.; Kaska, Y.; Jensen, M.P.; Mangel, J.C.; Mortimer, J.A.; Naro-Maciel, E.; Ng, C.K.Y.; Nichols, W.J.; Phillott, A.D.; Reina, R.D.; Revuelta, O.; Schofield, G.; Seminoff, J.A.; Shanker, K.; Tomás, J.; van de Merwe, J.P.; Van Houtan, K.S.; Vander Zanden, H.B.; Wallace, B.P.; Wedemeyer-Strombel, K.R.; Work, Thierry M.; Godley, B.J.
Large reptiles and cold temperatures: Do extreme cold spells set distributional limits for tropical reptiles in Florida?
Distributional limits of many tropical species in Florida are ultimately determined by tolerance to low temperature. An unprecedented cold spell during 2–11 January 2010, in South Florida provided an opportunity to compare the responses of tropical American crocodiles with warm-temperate American alligators and to compare the responses of...Mazzotti, Frank J.; Cherkiss, Michael S.; Parry, Mark; Beauchamp, Jeff; Rochford, Mike; Smith, Brian J.; Hart, Kristen M.; Brandt, Laura A.
Biomarkers reveal sea turtles remained in oiled areas following the Deepwater Horizon oil spill
Assessments of large-scale disasters, such as the Deepwater Horizon oil spill, are problematic because while measurements of post-disturbance conditions are common, measurements of pre-disturbance baselines are only rarely available. Without adequate observations of pre-disaster organismal and environmental conditions, it is impossible to assess...Vander Zanden, Hannah B.; Bolten, Alan B.; Tucker, Anton D.; Hart, Kristen M.; Lamont, Margaret M.; Fujisaki, Ikuko; Reich, Kimberly J.; Addison, David S.; Mansfield, Katherine L.; Phillips, Katrina F.; Pajuelo, Mariela; Bjorndal, Karen A.
Spatial and temporal variability in estuary habitat use by American alligators
Estuarine habitat occupied by Alligator mississippiensis, a primarily freshwater species, is spatially and temporally heterogeneous largely due to a salinity gradient that fluctuates. Using long-term night light survey data, we examined seasonal patterns in alligators’ habitat use by size classes in midstream and downstream estuary...Fujisaki, Ikuko; Hart, Kristen M.; Cherkiss, Michael S.; Mazzotti, Frank J.; Beauchamp, Jeffrey S.; Jeffery, Brian M.; Brandt, Laura A.
Can you hear me now? Range-testing a submerged passive acoustic receiver array in a Caribbean coral reef habitat
Submerged passive acoustic technology allows researchers to investigate spatial and temporal movement patterns of many marine and freshwater species. The technology uses receivers to detect and record acoustic transmissions emitted from tags attached to an individual. Acoustic signal strength naturally attenuates over distance, but numerous...Selby, Thomas H.; Hart, Kristen M.; Fujisaki, Ikuko; Smith, Brian J.; Pollock, Clayton J; Hillis-Star, Zandy M; Lundgren, Ian; Oli, Madan K.
Betrayal: radio-tagged Burmese pythons reveal locations of conspecifics in Everglades National Park
The “Judas” technique is based on the idea that a radio-tagged individual can be used to “betray” conspecifics during the course of its routine social behavior. The Burmese python (Python bivittatus) is an invasive constrictor in southern Florida, and few methods are available for its control. Pythons are normally solitary...Smith, Brian J.; Cherkiss, Michael S.; Hart, Kristen M.; Rochford, Michael R.; Selby, Thomas H.; Snow, Ray W; Mazzotti, Frank J.
Somatic growth dynamics of West Atlantic hawksbill sea turtles: a spatio-temporal perspective
Somatic growth dynamics are an integrated response to environmental conditions. Hawksbill sea turtles (Eretmochelys imbricata) are long-lived, major consumers in coral reef habitats that move over broad geographic areas (hundreds to thousands of kilometers). We evaluated spatio-temporal effects on hawksbill growth dynamics over a 33-yr period and...Bjorndal, Karen A.; Chaloupka, Milani; Saba, Vincent S.; Diez, Carlos E.; van Dam, Robert P.; Krueger, Barry H.; Horrocks, Julia A.; Santos, Armando J.B.; Bellini, Cláudio; Marcovaldi, Maria A.G.; Nava, Mabel; Willis, Sue; Godley, Brendan J.; Gore, Shannon; Hawkes, Lucy A.; McGowan, Andrew; Witt, Matthew J.; Stringell, Thomas B.; Sanghera, Amdeep; Richardson, Peter B.; Broderick, Annette C.; Phillips, Quinton; Calosso, Marta C.; Claydon, John A.B.; Blumenthal, Janice; Moncada, Felix; Nodarse, Gonzalo; Medina, Yosvani; Dunbar, Stephen G.; Wood, Lawrence D.; Lagueux, Cynthia J.; Campbell, Cathi L.; Meylan, Anne B.; Meylan, Peter A.; Burns Perez, Virginia R.; Coleman, Robin A.; Strindberg, Samantha; Guzmán-H, Vicente; Hart, Kristen M.; Cherkiss, Michael S.; Hillis-Starr, Zandy; Lundgren, Ian; Boulon, Ralf H.; Connett, Stephen; Outerbridge, Mark E.; Bolten, Alan B.
Hawksbill satellite-tracking case study: Implications for remigration interval and population estimates
Hawksbill sea turtles (Eretmochelys imbricata) are circumtropically distributed and listed as Critically Endangered by the IUCN (Meylan & Donnelly 1999; NMFS & USFWS 1993). To aid in population recovery and protection, the Hawksbill Recovery Plan identified the need to determine demographic information for hawksbills, such as distribution...Sartain-Iverson, Autumn R.; Hart, Kristen M.; Fujisaki, Ikuko; Cherkiss, Michael S.; Pollock, Clayton; Lundgren, Ian; Hillis-Starr, Zandy
DNA and dispersal models highlight constrained connectivity in a migratory marine megavertebrate
Population structure and spatial distribution are fundamentally important fields within ecology, evolution, and conservation biology. To investigate pan-Atlantic connectivity of globally endangered green turtles (Chelonia mydas) from two National Parks in Florida, USA, we applied a multidisciplinary approach comparing genetic analysis and ocean...Naro-Maciel, Eugenia; Hart, Kristen M.; Cruciata, Rossana; Putman, Nathan F.
Habitat selection by green turtles in a spatially heterogeneous benthic landscape in Dry Tortugas National Park, Florida
We examined habitat selection by green turtles Chelonia mydas at Dry Tortugas National Park, Florida, USA. We tracked 15 turtles (6 females and 9 males) using platform transmitter terminals (PTTs); 13 of these turtles were equipped with additional acoustic transmitters. Location data by PTTs comprised periods of 40 to 226 d in varying...Fujisaki, Ikuko; Hart, Kristen M.; Sartain-Iverson, Autumn R.