Researchers finish long-term analysis of enduring effects

Sep 27, 2011 10:45 GMT  ·  By
Louisiana's Grand Terre Island marshes contaminated with oil; here, with a minnow trap
   Louisiana's Grand Terre Island marshes contaminated with oil; here, with a minnow trap

Investigators at the Louisiana State University (LSU), led by scientists Fernando Galvez and Andrew Whitehead, report in a new study that the 2010 BP/Deepwater Horizon oil spill which affected the Gulf of Mexico had drastic consequences for fish populations and species living in the area.

Shortly after the spill was subdued, experts said that the chances of the ecosystem being irreversible affected were very slim. This investigation shows that early estimates were overly-optimistic, indicating just how close various species came to collapse.

At this point, the Gulf of Mexico waters around the original spill site exhibit only low oil constituent concentrations. Even so, fish had a great deal to suffer from the toxic effects of the myriad chemicals making up natural crude.

Details of the new scientific investigation were published in this week's issue of the esteemed journal Proceedings of the National Academy of Sciences (PNAS). The survey extended from the Atlantic Ocean to Louisiana marshes, as the team wanted to be very thorough in its analysis.

Most often, the investigators discovered genetic and development abnormalities, as well as a very large number of instances in which the sea creatures simply died off. The analysis “also indicated impairment of fish reproduction,” Whitehead explains.

The investigation was made possible by a rapid response grant awarded to the LSU team by the US National Science Foundation (NSF). The Division of Environmental Biology (DEB) was the primary source of funding for the study.

“Joining remote-sensing of the spill with gene expression data from wild-caught killifish, these scientists have captured the effects of low-level exposure to pollutants on the long-term health of fish,” explains NSF DEB acting deputy director George Gilchrist.

“It's a landmark study in applying genomic technology to wild animal populations under stress,” the official goes on to say. One of the most important discoveries was that fish appeared to have lost gill function. The structures appeared damaged, and displayed erroneous protein expression patterns.

The result “is of concern because early life-stages of many organisms are particularly sensitive to the toxic effects of oil, and because marsh contamination occurred during the spawning season of many species,” Whitehead explains.