Scientists from the National Oceanic and Atmospheric Administration (NOAA) and Stanford University have discovered that oil pollution leads to heart attack in fish.

The research led by Stanford University Professor Barbara Block focused on the implications of the Deepwater Horizon oil spill, also known as BP Oil spill, which happened in 2010 affecting the Bluefin tuna which thrives in the Gulf of Mexico. To gather data, in vitro cells were taken from the cardiac tissue of the yellow fin tuna and the Bluefin tuna. Many of them were kept in captive at the Tuna Research Conservation Center in California and Monterey Bay Aquarium.

Data showed traces of polycyclic aromatic hydrocarbons (PAH) in the cells which block the flow of the calcium and potassium ions in and out of the fish's cell membranes. The flow of calcium and potassium ions is important to help the fish maintain regular heart rates.

The team explained that low concentrations of the oil are enough to disrupt the flow of these ions and cause an abnormal pace of heartbeat for the fish.

Furthermore, the study found out that not only the Bluefin tuna is affected by this problem. Electronic tagging of other fish in the area showed that other species including swordfish, blue marlin, and dolphin fish may have been exposed to dangerous amounts of PAHs.

"Until now, PAH's toxic properties were better known for their cancer-causing effects," study co-author NOAA ecotoxicology program manager Nathaniel Scholz said to the L.A Times.

"But our work is showing they also have properties that are cardiotoxic, particularly among early life stages of fish.", he added.

The study also found out that increased amounts of PAHs could be a common injury suffered by more fish species living within periphery of the Gulf of Mexico, as it is one of the most diverse ocean ecosystems in the planet.

 "This raises the possiblity that exposure to environmental PAHs in many animals -- including humans -- could lead to cardiac arrhythmias and bradycardia, or slowing of the heart," Block wrote in the study.

The study was published in the Feb. 14 issue of Science.