March 12, 2021 — Nearly 100 percent of the red snapper sampled in the Gulf of Mexico over a six-year period by University of South Florida (USF) marine scientists showed evidence of liver damage, according to a study reported in Aquatic Toxicology.
The study is the first to correlate the concentration of crude oil found in the workhorses of the digestive system — the liver, gall bladder, and bile — with microscopic indicators of disease, such as inflammation, degenerative lesions, and the presence of parasites. The team sampled nearly 570 fish from 72 Gulf locations between 2011 to 2017 in the wake of the historic 2010 Deepwater Horizon oil spill.
“The results add to the list of other species we’ve analyzed indicating early warning signs of a compromised ecosystem,” said Erin Pulster, PhD, first author of the study and researcher at the USF College of Marine Science.
Pulster and the team of researchers studying oil pollution in Gulf of Mexico fishes have previously reported high levels of oil exposure in yellowfin tuna, golden tilefish, and red drum as well.
The Gulf of Mexico not only experiences hundreds of annual oil spills with long-lasting effects such as the historic Deepwater Horizon spill in 2010 but is routinely subject to intense shipping traffic and collects pollutants from faraway places that flow in from coastlines and rivers like the Mighty Mississippi and the Rio Grande.
In this study Pulster and the team looked specifically at the most toxic component of crude oil called polycyclic aromatic compounds, or PAHs. PAH sources include old oil and gas rigs, fuel from boats and airplanes, and natural oil seeps, which are fractures on the seafloor that can add millions of barrels of oil to the Gulf every year.