Deepwater Horizon crude oil impacts the developing hearts of large predatory pelagic fish.
The Deepwater Horizon disaster released more than 636 million L of crude oil into the northern Gulf of Mexico. The spill oiled upper surface water spawning habitats for many commercially and ecologically important pelagic fish species. Consequently, the developing spawn (embryos and larvae) of tunas, swordfish, and other large predators were potentially exposed to crude oil-derived polycyclic aromatic hydrocarbons (PAHs). Fish embryos are generally very sensitive to PAH-induced cardiotoxicity, and adverse changes in heart physiology and morphology can cause both acute and delayed mortality. Cardiac function is particularly important for fast-swimming pelagic predators with high aerobic demand. Offspring for these species develop rapidly at relatively high temperatures, and their vulnerability to crude oil toxicity is unknown. We assessed the impacts of field-collected Deepwater Horizon (MC252) oil samples on embryos of three pelagic fish: bluefin tuna, yellowfin tuna, and an amberjack. We show that environmentally realistic exposures (1-15 µg/L total PAH) cause specific dose-dependent defects in cardiac function in all three species, with circulatory disruption culminating in pericardial edema and other secondary malformations. Each species displayed an irregular atrial arrhythmia following oil exposure, indicating a highly conserved response to oil toxicity. A considerable portion of Gulf water samples collected during the spill had PAH concentrations exceeding toxicity thresholds observed here, indicating the potential for losses of pelagic fish larvae. Vulnerability assessments in other ocean habitats, including the Arctic, should focus on the developing heart of resident fish species as an exceptionally sensitive and consistent indicator of crude oil impacts.
Ecotoxicology Program, Environmental Conservation Division, Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration, Seattle, WA 98112.
John P
JP
Incardona
Luke D
LD
Gardner
Tiffany L
TL
Linbo
Tanya L
TL
Brown
Andrew J
AJ
Esbaugh
Edward M
EM
Mager
John D
JD
Stieglitz
Barbara L
BL
French
Jana S
JS
Labenia
Cathy A
CA
Laetz
Mark
M
Tagal
Catherine A
CA
Sloan
Abigail
A
Elizur
Daniel D
DD
Benetti
Martin
M
Grosell
Barbara A
BA
Block
Nathaniel L
NL
Scholz
D000704:Analysis of Variance; D000818:Animals; D004625:Embryo, Nonmammalian / Q000187:drug effects; D005393:Fish Diseases / Q000139:chemically induced* / Q000473:pathology*; D008401:Gas Chromatography-Mass Spectrometry / Q000662:veterinary; D060851:Gulf of America; D006321:Heart / Q000187:drug effects* / Q000254:growth & development; D006331:Heart Diseases / Q000139:chemically induced / Q000473:pathology / Q000662:veterinary*; D049674:History, 21st Century; D007091:Image Processing, Computer-Assisted; D010578:Petroleum / Q000633:toxicity*; D059392:Petroleum Pollution / Q000266:history*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D014413:Tuna
D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons
damage assessment; embryology; heart development; oil spill