Environmental Protection Agency Scientist Mussels Up
By Maureen Johnson
While most people think of the menu from their favorite seafood restaurant when they hear the word “mussel,” EPA research chemist Barbara Bergen thinks: data collectors. Bergen, who works at the EPA’s Atlantic Ecology Division laboratory in Narragansett, Rhode Island, uses native blue mussels (Mytilus edulis) to monitor pollution levels during clean up activities at the New Bedford Harbor Superfund Site.
Blue mussels are filter feeders. They eat by straining tiny particles of plankton out of the seawater. As they strain out their food they consume contaminants, which build up in their tissue over time. This makes them valuable biomonitors—living organisms that can be studied to get a clearer picture of environmental conditions in a given area.
In New Bedford Harbor, the mussels are accumulating polychlorinated biphenyls, better known as PCBs. Bergen takes mussels from uncontaminated sites and transplants them into the harbor. Then, after a month, she collects the mussels and analyzes their tissue to get a measure of what is happening to PCB levels on the Superfund Site.
In the early 1990s, when clean up efforts began, the mussel study played a critical role in making sure dredging was not inadvertently leading to higher PCB levels by stirring up and spreading contaminants buried in the harbor’s muddy bottom.
Now, with a decade and a half’s worth of data collection behind them, EPA scientists have a strong baseline of information from which to track contamination levels across the harbor. They recently proposed extending the mussel study as part of a long-term monitoring project. The new study will measure chemical and biological changes in the harbor’s water, animals, and sediment as clean up progresses. As an added benefit, the data will be posted on a public Web site, so it can be readily available for future analysis and comparison.
Superfund projects are typically very expensive endeavors, so it is important to document and quantify the return on investment society gains in the form of a cleaner, safer environment. EPA’s proposal to combine the mussel research and the long-term monitoring program gives the cleanup team effective tools to evaluate its efforts. The clean up team is made up of professionals from EPA’s New England region, along with colleagues from the U.S. Army Corps of Engineers.
This project is an example of the important partnership among environmental regulation and science. The lessons learned here—particularly that PCB levels have not risen due to initial clean up activities—will be valuable for future Superfund Site clean ups, saving both time and money.