Tuna hearts 'affected by oil spill'
14 February 2014 Last updated at 15:49 GMT
Scientists say that tuna swimming in the Gulf of Mexico during the Deepwater Horizon oil spill may have experienced heart damage.
Lab research has demonstrated how crude oil chemicals can disrupt heart function in the fish.
The study, published in Science magazine, is part of the ongoing work to try to understand the impacts of the disaster.
Barbara Block, a professor of marine sciences at Stanford University, told our correspondent Jonathan Amos about the special facility she uses to study tuna.