Interview: Update of NOAA’s Mussel Watch Status and Trend Report

Bud Ward
National Ocean Service, National Centers for Coastal Ocean Science

March 27, 2009 — Gunnar Lauenstein, a scientist at NOS’s National Centers for Coastal Ocean Science, recently led a major effort to update NOAA’s landmark Mussel Watch Status and Trends Report. The update is the first ever national summary of data from NOAA’s Mussel Watch Project, the longest continuous contaminant monitoring program of U.S. coastal waters. The project analyzes chemical and biological contaminant trends in sediment and bivalve tissue collected at more than 280 coastal sites from 1986 to today.

 

Here Lauenstein addresses questions regarding key report findings, outlines ways various user groups can get the most out of the report, and explains key points derived from two decades of related research.

What makes this report unique?
GL: The report summarizes 20 years of data for a majority of the organic contaminants and trace elements monitored by the Mussel Watch Project in one place and in an easy–to–understand format. Data is presented at national, regional and individual site levels. Typically, scientific papers only focus on one contaminant or group of contaminants.

Who is the target audience for this report, and how are they using the data?
GL: The report was intended for individuals and organizations that want access to a synopsis of national Mussel Watch monitoring results for the nation’s coasts and Great Lakes. These data have been used to confirm the success of legislation enacted to reduce environmental contamination over the last 20 years. However, the results also indicate areas where more work is needed.

Why use mussels and oysters to assess ecosystem contamination, especially when it comes to water quality?
GL: Mussels and oysters are very useful for this type of environmental monitoring. Since they do not metabolize contaminants, such as those resulting from spilled petroleum or fossil fuel burning, you can determine exactly what contaminants the marine animals were exposed to. They also filter–feed, using relatively large volumes of seawater, so you also can obtain an integrated signature of water contaminants in the area of a monitoring site. Lastly, because they are sessile — they remain in one place — you can revisit the same location year after year in order to determine contaminant trends through time.

What are the report findings? Are conditions improving or getting worse?
GL: In general, conditions are improving. Many of the contaminants monitored by the Mussel Watch Program have decreased over the last 20 years. Decreasing concentrations on a national scale were found for butyltins, which were used as anti–fouling compounds on boats; PCBs, which were industrial chemicals used in electrical products; and DDT, a formerly widely used pesticide. Decreasing trends were also documented for other organic compounds and for some elements. Results can be found in the report: Mussel Watch Program: An Assessment of Two Decades of Contaminant Monitoring in the Nation’s Coastal Zone.

What does the report say about the effectiveness of nationwide programs aimed at reducing contaminant levels?
GL: Data from this Program clearly demonstrate that environmental regulations like those that banned the use of DDT and PCBs in the 1970s have had their intended effect, which is to improve the environmental condition of the nation.

Can the report also be used to address shellfish consumption issues?
GL: No. The Program’s mussel and oyster sites do not necessarily coincide with commercial and recreational shellfishing areas. Contaminant levels in the Program’s mussels and oysters could therefore be lower or higher than concentrations found in adjacent shellfishing areas.

How can this report be used to help assess the effects of climate change?
GL: Mussel Watch is frequently perceived as only a chemical monitoring program, but mussels and oysters are also characterized for incidence of disease and parasites. There is a correlation between disease incidence and water temperature or certain parasites and disease organisms are limited by colder temperatures found further north. Thus, as the world’s oceans warm, we may see the spread of certain disease organisms in mussels and oysters.

What products can we expect next from NOAA’s Mussel Watch Program?
GL: We are currently completing the first ever national review of flame retardants, known as polybrominated diphenyl ethers (PBDEs), in the coastal environments of the U.S. Results of this effort will be available in the near future.