4:24pm

Mon March 24, 2014
Environment

The Hearts Of Fish Still Bear Scars Of Oil Spilled Years Ago

Originally published on Mon March 24, 2014 6:46 pm

Transcript

AUDIE CORNISH, HOST:

The spill in the Houston Ship Channel is another assault on one of the world's richest fishing grounds. The channel drains into the Gulf of Mexico and new research out today shows the Gulf's marine life is very vulnerable to the effects of oil. Much of what scientists have learned comes from studying the underwater leak of the Deepwater Horizon oil rig back in 2010. Here's NPR's Elizabeth Shogren.

ELIZABETH SHOGREN, BYLINE: Scientists knew even trace amounts of oil can kill or injure fish eggs and young fish. But they didn't know how the BP oil would hurt the fish eggs that were in the Gulf of Mexico during the BP spill, such as bluefin tuna.

DR. JOHN INCARDONA: It's extremely challenging to capture those from the open ocean and get them under a microscope and look at them alive. So we weren't able to do that.

SHOGREN: Dr. John Incardona is a toxicologist with the National Oceanic and Atmospheric Administration. He and other researchers did the next best thing. They took samples of the oil from the BP spill to tuna hatcheries in Australia and Panama. They wanted to mimic the way the oil shot out of the well and dispersed into the gulf. So researchers used blenders to mix tiny amounts of oil into seawater. Then they exposed the fish eggs. NOAA scientist Nat Sholz says at relatively higher concentrations, the tuna had severe heart injuries and other deformities.

NAT SHOLZ: And these fish are not likely to survive when they hatch because they'll be unable to feed.

SHOGREN: At lower concentrations, fish had milder heart injuries that would make them slower swimmers and easy prey. Stanford University tuna expert Barbara Block says she knows bluefin were spawning in the Gulf because of information from electronic devices that tracked the animals.

BARBARA BLOCK: The satellite tags have placed the bluefin tuna literally at the scene of the crime when it occurred.

SHOGREN: Now she's trying to determine what portion of the overall population was in harm's way. The findings grew out of 25 years of science that followed the Exxon Valdez spill in Alaska. The study was published in the Proceedings of the National Academy of Sciences. Elizabeth Shogren, NPR News. Transcript provided by NPR, Copyright NPR.