Several Gulf of Mexico fish embryos developed serious heart abnormalities following exposure to crude oil from the Deepwater Horizon oil spill in 2010, according to a new study carried out by the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science.
The study assessed the impacts of polycyclic aromatic hydrocarbons (PAHs) released from crude oil, from Deepwater Horizon oil samples on embryos of bluefin tuna, Yellowfin tuna and amberjack. Embryos were exposed to two different oil samples, one collected from surface skimming operations and another from the source pipe attached to the damaged wellhead.
Daniel Benetti, professor of marine affairs and policy, UM Rosenstiel School, said: “This study is the first to understand the impacts of the Deepwater Horizon oil spill on the early life development of commercially important fish in the Gulf of Mexico.
A significant number of the water samples collected contained PAH concentrations exceeding the toxicity thresholds observed in the study.
The embryos used for the study were collected from research broodstock located at land-based fish hatcheries in Australia and Panama.
Exposure to each oil type produced virtually identical defects in embryos of all three tested species, the study revealed. For each species, oil exposures caused serious defects in heart development and abnormalities in cardiac function, indicating crude oil cardiotoxicity.
Bluefin tuna showed the highest percentage of larvae with the entire set of defects, and their populations are currently listed as endangered due to historically low levels.
The findings can be applied to fisheries management questions in marine regions where crude oil extraction is prevalent, added Mr Benetti.
The Deepwater Horizon oil spill in the northern Gulf of Mexico released more than four million barrels of crude oil into the surrounding waters during the seasonal spawning window for bluefin and Yellowfin tuna, mahi mahi, king and Spanish mackerels, greater and lesser amberjack, sailfish, blue marlin and cobia all commercially and ecologically important open-ocean fish species.
Mercator Media 2014