During Fall 2007, MARINe teamed up with federal, state, and local agencies to add 13 new sites to a network of locations where mussels are collected for water quality analysis. This increase results in a total of 34 Mussel Watch sites in southern California. Of these, 15 are now at or near MARINe monitoring sites, and 19 are at other locations such as at the mouths of rivers, harbors and lagoons.
Because the mussel is a “filter-feeding” marine animal, a clam relative that feeds by passing water through its gills to filter out small plankton, it concentrates chemicals from the surrounding waters in its tissue. Even tiny amounts of pollution in the water can be detected by examining mussel tissue. The “Mussel Watch” program sponsored by NOAA (National Oceanographic and Atmospheric Administration) uses this principle to monitor water quality nationally. Mussel tissues are analyzed for levels of heavy metals, hydrocarbons, and pathogens (bacteria linked to diseases or parasites). The data collected are valuable for resource managers to identify polluted sections of the coast and take action to restore water quality. Emphasis on coupling Mussel Watch locations with State-designated “Areas of Special Biological Significance” and established MARINe monitoring sites will enhance scientist’s abilities to compare contaminant levels with other biological information to greatly improve resource management efforts.
NOAA’s Status and Trends Mussel Watch program is the longest continuous contaminant monitoring program in U.S. coastal waters. Data from approximately 280 sites has been gathered since 1986; earlier data collected by EPA extends back to the 1970’s. The Program analyzes bivalve tissue samples for 140 different chemicals, including trace elements (e.g., copper, lead, mercury, zinc) and organics such as chlorinated pesticides (e.g., DDT), industrial polychlorinated biphenlys (PCB’s), vessel antifouling agents (e.g., tributyltin), oil-related polycylic aromatic hydrocarbons (PAH’s), and flame retardants (PBDE’s). In addition, it monitors parasite infections and disease effects.
Mussel Watch is the first nationwide monitoring program to use a quantitative approach to histopathological (tissue) analysis. Histopathology surveys are an important component of monitoring for environmental pollution because the physiological health of an organism can be affected by its contaminant body burden.
Mussels are good bioindicators of coastal water quality because they concentrate pollutants from the water, they are sedentary yet widely distributed, and because they can survive in areas where less hardy species may be absent. Mussels not only serve as excellent indicators of intertidal community conditions, but also raise public health concerns because they are consumed by seafood lovers with easy access to coastal reefs.
The Southern California Coastal Water Research Project (SCCWRP) arranged the collaboration with NOAA Mussel Watch, the California State Water Boards Areas of Special Biological Significance (ASBS) Program, and the Multi-Agency Rocky Intertidal Network (MARINe). Scientists from these agencies evaluated existing Mussel Watch sites and chose new sites to fill in regional gaps, with emphasis placed on locating sample locations in ASBS and at or near MARINe rocky intertidal life survey reefs.
MARINe monitors 45 rocky intertidal reefs throughout southern California, with mussels surveyed in permanent photoplots at all but one of these locations. Fifteen of these sites will now have Mussel Watch data that can be compared with mussel and other intertidal species abundance trends. MARINe surveys at Point Loma, San Diego, revealed catastrophic declines in mussel cover that have practically eliminated this keystone species from its zone of former dominance. Region-wide coupling of tissue contaminant and pathogen burdens with population monitoring will help in determining the cause and possible solutions for adverse marine resource trends such as the mysterious Point Loma mussel decimation.
Mussel Watch results are provided to scientists, resource managers, and the public via publications and a website data portal.
