title: Biomarkers reveal sea turtles remained in oiled areas following the Deepwater Horizon oil spill.
abstract: 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 the impact of such catastrophes on animal populations and ecological communities. Here, we use long-term biological tissue records to provide pre-disaster data for a vulnerable marine organism. Keratin samples from the carapace of loggerhead sea turtles record the foraging history for up to 18 years, allowing us to evaluate the effect of the oil spill on sea turtle foraging patterns. Samples were collected from 76 satellite-tracked adult loggerheads in 2011 and 2012, approximately one to two years after the spill. Of the 10 individuals that foraged in areas exposed to surface oil, none demonstrated significant changes in foraging patterns post spill. The observed long-term fidelity to foraging sites indicates that loggerheads in the northern Gulf of Mexico likely remained in established foraging sites, regardless of the introduction of oil and chemical dispersants. More research is needed to address potential long-term health consequences to turtles in this region. Mobile marine organisms present challenges for researchers to monitor effects of environmental disasters, both spatially and temporally. We demonstrate that biological tissues can reveal long-term histories of animal behavior and provide critical pre-disaster baselines following an anthropogenic disturbance or natural disaster.
authors.affiliation: Department of Geology and Geophysics, University of Utah, 115 S 1460 E Salt Lake City, Utah, 84112, USA. h.vanderzanden@utah.edu.|Archie Carr Center for Sea Turtle Research and Department of Biology, University of Florida, PO Box 118525 Gainesville, Florida, 32611, USA. h.vanderzanden@utah.edu.
authors.forename: Hannah B
authors.initials: HB
authors.lastname: Vander Zanden
authors.affiliation: Archie Carr Center for Sea Turtle Research and Department of Biology, University of Florida, PO Box 118525 Gainesville, Florida, 32611, USA.
authors.forename: Alan B
authors.initials: AB
authors.lastname: Bolten
authors.affiliation: Mote Marine Laboratory, 1600 Ken Thompson Pkwy, Sarasota, Florida, 34236, USA.
authors.forename: Anton D
authors.initials: AD
authors.lastname: Tucker
authors.affiliation: Wetland and Aquatic Research Center, U.S. Geological Survey, 3321 College Ave, Davie, Florida, 33314, USA.
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Hart
authors.affiliation: Wetland and Aquatic Research Center, U.S. Geological Survey, 7920 NW 71St St, Gainesville, Florida, 32653, USA.
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Lamont
authors.affiliation: Ft. Lauderdale Research and Education Center, University of Florida, 3205 College Ave, Davie, Florida, 33314, USA.
authors.forename: Ikuko
authors.initials: I
authors.lastname: Fujisaki
authors.affiliation: Texas A & M Galveston, P.O. Box 1675, Galveston, Texas, 77553, USA.
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Reich
authors.affiliation: Conservancy of Southwest Florida, 1495 Smith Preserve Way, Naples, Florida, 34102, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: Addison
authors.affiliation: Department of Biology, University of Central Florida, 4110 Libra Dr, Orlando, Florida, 32816, USA.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Mansfield
authors.affiliation: Department of Biology, University of Central Florida, 4110 Libra Dr, Orlando, Florida, 32816, USA.
authors.forename: Katrina F
authors.initials: KF
authors.lastname: Phillips
authors.affiliation: Archie Carr Center for Sea Turtle Research and Department of Biology, University of Florida, PO Box 118525 Gainesville, Florida, 32611, USA.
authors.forename: Mariela
authors.initials: M
authors.lastname: Pajuelo
authors.affiliation: Archie Carr Center for Sea Turtle Research and Department of Biology, University of Florida, PO Box 118525 Gainesville, Florida, 32611, USA.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Bjorndal
mesh_terms: D063147:Animal Distribution; D000818:Animals; D002247:Carbon Isotopes; D000074062:Environmental Biomarkers; D005260:Female; D060851:Gulf of America; D009587:Nitrogen Isotopes; D059392:Petroleum Pollution; D012867:Skin / Q000737:chemistry / Q000473:pathology; D014426:Turtles / Q000502:physiology*
chemical_list: D002247:Carbon Isotopes; D000074062:Environmental Biomarkers; D009587:Nitrogen Isotopes
keywords: 
  Caretta caretta
  ; Deepwater Horizon; Gulf of Mexico; loggerhead; oil spill; petroleum hydrocarbons; resource use; stable isotopes