On treating an inch-long embryonic fish, mahi-mahi, in an oil tank for long time, researchers found change in swimming practices of the ocean's fastest fish. They performed an experiment to assess the damage caused by the BP Deepwater Horizon Oil across the Gulf of Mexico for 87 days in 2010 on health of the fish.

Young mahimahi usually swims at a rate of five body lengths per second and are known as species that needs speed for survival. Martin Grosell, one of the study's authors, said that any life form is optimized compromise.

Researchers from the University of Miami Rosenstiel School of Marine and Atmospheric Science have concluded that oil from the largest spill in U. S. history has damaged young pelagic fish. Also, the BP oil spill caused huge damage to the hearts of tuna embryos, said the UM researchers in March.

The two studies on Tuna and Mahi fish reported 75% drop in Tuna population in the last 40 years. On the contrary, the BP Company considers the findings to be false as they believe that the tests used different concentrations of oil than the one found in the Gulf during or after the spill.

"Even if there had been an effect on single-year class of such fish, the study does not provide evidence that an effect on that group of fish would have had population-level impact", said Jason Ryan, Spokesman from the BP.