title: Reproductive outcome and survival of common bottlenose dolphins sampled in Barataria Bay, Louisiana, USA, following the Deepwater Horizon oil spill.
abstract: Common bottlenose dolphins (Tursiops truncatus) inhabit bays, sounds and estuaries across the Gulf of Mexico. Following the Deepwater Horizon oil spill, studies were initiated to assess potential effects on these ecologically important apex predators. A previous study reported disease conditions, including lung disease and impaired stress response, for 32 dolphins that were temporarily captured and given health assessments in Barataria Bay, Louisiana, USA. Ten of the sampled dolphins were determined to be pregnant, with expected due dates the following spring or summer. Here, we report findings after 47 months of follow-up monitoring of those sampled dolphins. Only 20% (95% CI: 2.50-55.6%) of the pregnant dolphins produced viable calves, as compared with a previously reported pregnancy success rate of 83% in a reference population. Fifty-seven per cent of pregnant females that did not successfully produce a calf had been previously diagnosed with moderate-severe lung disease. In addition, the estimated annual survival rate of the sampled cohort was low (86.8%, 95% CI: 80.0-92.7%) as compared with survival rates of 95.1% and 96.2% from two other previously studied bottlenose dolphin populations. Our findings confirm low reproductive success and high mortality in dolphins from a heavily oiled estuary when compared with other populations. Follow-up studies are needed to better understand the potential recovery of dolphins in Barataria Bay and, by extension, other Gulf coastal regions impacted by the spill.
authors.affiliation: National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Hollings Marine Laboratory, Charleston, SC, USA.
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Lane
authors.affiliation: National Marine Mammal Foundation, San Diego, CA, USA.
authors.forename: Cynthia R
authors.initials: CR
authors.lastname: Smith
authors.affiliation: Western Ecosystems Technology, Inc., Cheyenne, WY, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Mitchell
authors.affiliation: National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Hollings Marine Laboratory, Charleston, SC, USA Chicago Zoological Society, c/o Mote Marine Laboratory, Sarasota, FL, USA.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Balmer
authors.affiliation: National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Pascagoula, MS, USA.
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Barry
authors.affiliation: Western Ecosystems Technology, Inc., Cheyenne, WY, USA.
authors.forename: Trent
authors.initials: T
authors.lastname: McDonald
authors.affiliation: Industrial Economics, Inc., Cambridge, MA, USA.
authors.forename: Chiharu S
authors.initials: CS
authors.lastname: Mori
authors.affiliation: National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Lafayette, LA, USA.
authors.forename: Patricia E
authors.initials: PE
authors.lastname: Rosel
authors.affiliation: National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Office of Protected Resources, Silver Spring, MD, USA.
authors.forename: Teresa K
authors.initials: TK
authors.lastname: Rowles
authors.affiliation: National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Hollings Marine Laboratory, Charleston, SC, USA.
authors.forename: Todd R
authors.initials: TR
authors.lastname: Speakman
authors.affiliation: Bayside Hospital for Animals, Fort Walton Beach, FL, USA.
authors.forename: Forrest I
authors.initials: FI
authors.lastname: Townsend
authors.affiliation: Louisiana Department of Wildlife and Fisheries, Baton Rouge, LA, USA.
authors.forename: Mandy C
authors.initials: MC
authors.lastname: Tumlin
authors.affiliation: Chicago Zoological Society, c/o Mote Marine Laboratory, Sarasota, FL, USA.
authors.forename: Randall S
authors.initials: RS
authors.lastname: Wells
authors.affiliation: National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Hollings Marine Laboratory, Charleston, SC, USA.
authors.forename: Eric S
authors.initials: ES
authors.lastname: Zolman
authors.affiliation: National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Hollings Marine Laboratory, Charleston, SC, USA lori.schwacke@noaa.gov.
authors.forename: Lori H
authors.initials: LH
authors.lastname: Schwacke
mesh_terms: D000818:Animals; D061006:Bays; D050681:Bottle-Nosed Dolphin; D005260:Female; D060851:Gulf of America; D008145:Louisiana / Q000453:epidemiology; D008297:Male; D009026:Mortality; D059392:Petroleum Pollution / Q000009:adverse effects*; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000662:veterinary*; D012098:Reproduction / Q000187:drug effects*
keywords: Deepwater Horizon; Tursiops truncatus; bottlenose dolphin; oil spill; reproductive outcome; survival