Young Fish Exposed to Deepwater Horizon Oil Develop Defects in Their Hearts

It doesn't take a huge leap in logic to imagine that dumping 200 million gallons of oil and 2 million gallons of chemical dispersants into a body of water would impact the animals there. Yet it's surprisingly difficult to link events such as the Deepwater Horizon oil spill to environmental impacts. The ecotoxicology studies that establish these connections are notoriously difficult to do and tend to struggle to find funding and support. 

Now, however, a team of NOAA researchers has established a link between the 2010 oil spill in the Gulf Coast and impacts on wildlife. Fish that were exposed as embryos or juveniles to the Deepwater Horizon oil, the researchers found, suffer from heart defects that could impact their ability to survive into adulthood and reproduce, the Washington Post reports. 

The researchers didn't look directly at fish in the Gulf of Mexico. Rather, they created mini-oil spills in their lab that mimicked conditions back in 2010. Then, they exposed baby yellowfin and bluefin tuna and amberjack to the potentially deadly mix. According to the Washington Post, they found that "[i]n the three species studied, abnormalities were clear. Heart contractions were observed and asymmetry was apparent. The deformities continued after the eggs hatched." Here's what the researchers reported in Proceedings of the National Academy of Sciences:

Abnormalities in cardiac function were highly consistent...Losses of early life stages were therefore likely for Gulf populations of tunas, amberjack, swordfish, billfish, and other large predators that spawned in oiled surface habitats.

Tuna, for instance, take eight years to mature, Washington Post explains, and they can only be caught commercially once they reach that age. Since only four years have passed since the spill occurred, it could be that future catch rates will suddenly decline, reflecting the damage done in 2010. 

Last summer, BP filed a lawsuit in Texas "arguing it had been sufficiently punished for the spill," the Post adds, and the EPA recently lifted the ban preventing the company from bidding on federal oil and gas reserves. However, it will likely be many years before the full extent of impacts caused by the 2010 spill will be revealed. 

Rachel Nuwer | | READ MORE

Rachel Nuwer is a freelance science writer based in Brooklyn.