March 31, 2014 — The BP Deepwater Horizon oil spill struck at the very heart of fish, a new study says. Exposed to millions of gallons of crude, young tuna and amberjack, some of the speediest predators in the ocean, developed heart defects that are likely to limit their ability to catch food.
The findings of the study, led by the National Oceanic and Atmospheric Administration, have grim implications for the future of yellowfin and bluefin tuna, as well as amberjack, that were embryos, larvae or juveniles when the spill occurred during tuna-spawning season in the northern Gulf of Mexico in April 2010.
Embryos are highly sensitive, so fragile that it is possible to see through them. When scientists re-created the conditions of the spill in a lab, exposing tuna and amberjack in the developmental stage to an oil slick, they observed “a slowing of their heartbeats,” said Barbara Block, a biology professor at Stanford University who co-authored the study.
“They’re not going to be able to survive” as they develop into adult fish, said Nat Scholz, leader of the ecotoxicology program at NOAA’s Northwest Fisheries Science Center in Seattle. “You’re going to be losing those fish from the adult spawning population.”
The study — “Deepwater Horizon crude oil impacts the developing hearts of large predatory pelagic fish” — was published Monday in the Proceedings of the National Academy of Sciences on the 25th anniversary of the Exxon Valdez oil spill in Alaska’s Prince William Sound.
Research conducted on fish after the 1989 Exxon Valdez spill had similar findings, but the exposed population then was smaller because the 11-million-gallon spill collected closer to the shore, killing an estimated 250,000 birds.