Oil spilled during the 2010 Deepwater Horizon disaster caused severe defects in the developing hearts of tuna exposed to the substance in a laboratory, according to a study by government and academic scientists that hints at long-term damage from the accident.
The research, published this week in Proceedings of the National Academy of Sciences, shows that the crude that gushed out of BP's failed Macondo well for nearly three months could have compromised tuna embryos and larvae, killing off some of the fish and shortening the lives of others.
The research comes 25 years after crude from the tanker Exxon Valdez devastated Alaska's Prince William Sound, and as another, albeit much smaller, spill threatens Galveston Bay aquatic life in ways that may not appear for years.
"Oil's damage doesn't disappear overnight, nor does it cease after the oil sheen goes away," said Jacqueline Savitz, a vice president at the conservation group Oceana.
The study -- along with research published in the Feb. 14 issue of the journal Science -- shows that polyaromatic hydrocarbons in crude harm heart development in bluefin tuna, amberjack and yellowfin tuna by slowing the heart beat and disrupting its rhythm.
"Crude oil shuts down key cellular processes in fish heart valves," said Barbara Block, a professor of marine science at Stanford University and a co-author of the paper. "We can now say with certainty that oil causes cardiotoxic injuries in tuna, and we know the mechanism of exactly how this occurs."
Tuna are large predatory fish that spawn in the northern Gulf of Mexico during the spring and summer -- just when BP's well was sending oil into the water four years ago. Because the fish embryos stay near the surface, they were especially susceptible to floating crude.
The study published this week does not document long-term damage to adult tuna, long-lived species that cannot be fished commercially until they are 8 years old.
But John Incardona, a research toxicologist with the National Oceanic and Atmospheric Administration, and the lead author of the paper, said the heart defects materializing in the young tuna could inhibit their swimming ability later on.
Even when exposed to lower concentrations of oil, "fish that looked morphologically normal on the outside still had abnormal heart rhythms," Incardona said. Those fish might survive but might die prematurely.
Researchers from the National Oceanic and Atmospheric Administration, Stanford and other universities, said the damage they documented to the young tuna in a Queensland, Australia, laboratory is consistent with defects observed in Prince William Sound herring exposed to crude when the Exxon Valdez tanker ruptured in 1989.
The new study, which used crude collected from the Gulf of Mexico, was designed to emulate environmental conditions at the time of the disaster. Researchers exposed the transparent embryos to crude and used digital microscopes to capture video, revealing the heart rates and rhythms in the fish, the size of the heart chambers, the thickness of the muscle walls and other characteristics.
BP questioned the methodology, saying that oil concentrations used in the lab experiments exceeded those in the Gulf during the 2010 spill.
"The paper provides no evidence to suggest a population-level impact on tuna, amberjack or other pelagic fish species in the Gulf of Mexico," said Jason Ryan, a spokesman for the company. "The authors themselves note that it is nearly impossible to determine the early life impact to these species. To overcome this challenge, it would take more information than what's presented in this paper." ___
(c)2014 the Houston Chronicle
Visit the Houston Chronicle at www.chron.com
Distributed by MCT Information Services
Our 2024 Coverage Needs You
It's Another Trump-Biden Showdown — And We Need Your Help
The Future Of Democracy Is At Stake
Our 2024 Coverage Needs You
Your Loyalty Means The World To Us
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
The 2024 election is heating up, and women's rights, health care, voting rights, and the very future of democracy are all at stake. Donald Trump will face Joe Biden in the most consequential vote of our time. And HuffPost will be there, covering every twist and turn. America's future hangs in the balance. Would you consider contributing to support our journalism and keep it free for all during this critical season?
HuffPost believes news should be accessible to everyone, regardless of their ability to pay for it. We rely on readers like you to help fund our work. Any contribution you can make — even as little as $2 — goes directly toward supporting the impactful journalism that we will continue to produce this year. Thank you for being part of our story.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
It's official: Donald Trump will face Joe Biden this fall in the presidential election. As we face the most consequential presidential election of our time, HuffPost is committed to bringing you up-to-date, accurate news about the 2024 race. While other outlets have retreated behind paywalls, you can trust our news will stay free.
But we can't do it without your help. Reader funding is one of the key ways we support our newsroom. Would you consider making a donation to help fund our news during this critical time? Your contributions are vital to supporting a free press.
Contribute as little as $2 to keep our journalism free and accessible to all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. Would you consider becoming a regular HuffPost contributor?
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. If circumstances have changed since you last contributed, we hope you'll consider contributing to HuffPost once more.
Support HuffPostAlready contributed? Log in to hide these messages.