Study Finds Three Ways Oill Spill Impacts Gulf Seaweed

January 6, 2015

Mississippi and Alabama scientists investigated oil spill effects on floating Sargassum, a critical seaweed habitat for many important Gulf species.

They observed disappearance during and after the Deepwater Horizon spill and then conducted mesocosm experiments with Louisiana sweet crude oil and Corexit 9500 dispersant to test the fate of oiled Sargassum. They found that oil accumulated on the seaweed, potentially exposing young fish to concentrated pollutants. The combination of oil and dispersant caused the seaweed to sink, thus removing the habitat. From the initial seaweed oiling to its sinking, reduced oxygen levels in the oiled treatments may have also stressed marine life.

Maggie Dannreuther, GoMRI program writer, posted a summary of the study here.

The researchers published their findings in the journal Public Library of Science (PLoS) One: Novel pathways for injury from offshore oil spills: Direct, sublethal and indirect effects of the Deepwater Horizon oil spill on pelagic Sargassum communities.

This research was made possible in part by grants from the Gulf of Mexico Research Initiative (GoMRI) to the Alabama Marine Environmental Science Consortium, the University of Southern Mississippi, and the Northern Gulf Institute. Other funding included a National Science Foundation RAPID grant from the Division of Ocean Sciences.

The GoMRI is a 10-year independent research program established to study the effect, and the potential associated impact, of hydrocarbon releases on the environment and public health, as well as to develop improved spill mitigation, oil detection, characterization and remediation technologies. An independent and academic 20-member Research Board makes the funding and research direction decisions to ensure the intellectual quality, effectiveness and academic independence of the GoMRI research. All research data, findings and publications will be made publicly available. The program was established through a $500 million financial commitment from BP. For more information, visit http://gulfresearchinitiative.org/.