431
© Springer Nature Switzerland AG 2020
S. A. Murawski et al. (eds.), Deep Oil Spills,
https://doi.org/10.1007/978-3-030-11605-7_26
Chapter 26
Impacts of the Deepwater Horizon Oil Spill
on Marine Mammals and Sea Turtles
Kaitlin E. Frasier, Alba Solsona-Berga, Lesley Stokes,
and John A. Hildebrand
Abstract The Gulf of Mexico (GOM) is one of the most diverse ecosystems in the
world (Fautin et al. PLoS One 5(8):e11914, 2010). Twenty-one species of marine
mammals and five species of sea turtles were routinely identified in the region by
the end of the twenty-first century (Waring et al. NOAA Tech Memo NMFS NE
231:361, 2015), a decrease from approximately 39 species prior to intensive exploitation (Darnell RM. The American sea: a natural history of the Gulf of Mexico.
Texas A&M University Press, College Station, TX, 2015). Life histories of these
megafauna species range from hyperlocal residence patterns of bottlenose dolphins
to inter-ocean migrations of leatherback turtles. All species are subject to direct and
indirect impacts associated with human activities. These impacts have intensified
with major development and extraction efforts since the 1940s. The Deepwater
Horizon (DWH) oil spill represents a new type of injury to this system: Unlike previous large oil spills, it not only exposed marine megafauna to surface slicks, it also
involved an unprecedented release of dispersed oil into deep waters and pelagic
habitats, where effects are difficult to observe and quantify. This chapter synthesizes
the research conducted following the DWH oil spill to characterize acute and
chronic offshore effects on oceanic marine mammals and sea turtles. Marine mammals and sea turtles were exposed to unprecedented amounts of oil and dispersants.
Local declines in marine mammal presence observed using passive acoustic monitoring data suggest that the acute and chronic population-level impacts of this exposure were likely high and were underestimated based on coastal observations alone.
These population declines may be related to reduced reproductive success as
observed in nearshore proxies. Long-term monitoring of oceanic marine mammals
is a focus of this chapter because impacts to these populations have not been extensively covered elsewhere. We provide an overview of impacts to sea turtles and
K. E. Frasier (*) · A. Solsona-Berga · J. A. Hildebrand
University of California San Diego, Scripps Institution of Oceanography, Marine Physical
Laboratory, La Jolla, CA, USA
e-mail: kfrasier@ucsd.edu; asolsonaberga@ucsd.edu; jhildebrand@ucsd.edu
L. Stokes
National Marine Fisheries Service, Southeast Fisheries Science Center, Miami, FL, USA
e-mail: lesley.stokes@noaa.gov
© Springer Nature Switzerland AG 2020
S. A. Murawski et al. (eds.), Deep Oil Spills,
https://doi.org/10.1007/978-3-030-11605-7_26
Chapter 26
Impacts of the Deepwater Horizon Oil Spill
on Marine Mammals and Sea Turtles
Kaitlin E. Frasier, Alba Solsona-Berga, Lesley Stokes,
and John A. Hildebrand
Abstract The Gulf of Mexico (GOM) is one of the most diverse ecosystems in the
world (Fautin et al. PLoS One 5(8):e11914, 2010). Twenty-one species of marine
mammals and five species of sea turtles were routinely identified in the region by
the end of the twenty-first century (Waring et al. NOAA Tech Memo NMFS NE
231:361, 2015), a decrease from approximately 39 species prior to intensive exploitation (Darnell RM. The American sea: a natural history of the Gulf of Mexico.
Texas A&M University Press, College Station, TX, 2015). Life histories of these
megafauna species range from hyperlocal residence patterns of bottlenose dolphins
to inter-ocean migrations of leatherback turtles. All species are subject to direct and
indirect impacts associated with human activities. These impacts have intensified
with major development and extraction efforts since the 1940s. The Deepwater
Horizon (DWH) oil spill represents a new type of injury to this system: Unlike previous large oil spills, it not only exposed marine megafauna to surface slicks, it also
involved an unprecedented release of dispersed oil into deep waters and pelagic
habitats, where effects are difficult to observe and quantify. This chapter synthesizes
the research conducted following the DWH oil spill to characterize acute and
chronic offshore effects on oceanic marine mammals and sea turtles. Marine mammals and sea turtles were exposed to unprecedented amounts of oil and dispersants.
Local declines in marine mammal presence observed using passive acoustic monitoring data suggest that the acute and chronic population-level impacts of this exposure were likely high and were underestimated based on coastal observations alone.
These population declines may be related to reduced reproductive success as
observed in nearshore proxies. Long-term monitoring of oceanic marine mammals
is a focus of this chapter because impacts to these populations have not been extensively covered elsewhere. We provide an overview of impacts to sea turtles and
K. E. Frasier (*) · A. Solsona-Berga · J. A. Hildebrand
University of California San Diego, Scripps Institution of Oceanography, Marine Physical
Laboratory, La Jolla, CA, USA
e-mail: kfrasier@ucsd.edu; asolsonaberga@ucsd.edu; jhildebrand@ucsd.edu
L. Stokes
National Marine Fisheries Service, Southeast Fisheries Science Center, Miami, FL, USA
e-mail: lesley.stokes@noaa.gov