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A PROBABILISTIC ASSESSMENT OF BENTHIC CONDITION OF CALIFORNIA ESTUARIES: RESULTS FROM THE NATIONAL COASTAL ASSESSMENT 1999
Citation:
Nelson, W G., H Lee II, AND J O. Lamberson. A PROBABILISTIC ASSESSMENT OF BENTHIC CONDITION OF CALIFORNIA ESTUARIES: RESULTS FROM THE NATIONAL COASTAL ASSESSMENT 1999. Presented at 31st Annual Marine Benthic Ecology Meeting, Orlando, FL, March 22-24, 2002.
Description:
As part of the National Coastal Assessment, the Environmental Monitoring and Assessment Program of EPA is conducting a three year evaluation of benthic habitat condition of California estuaries. In 1999, probabilistic sampling for a variety of biotic and abiotic condition indicators was conducted at eighty stations in all California estuaries except San Francisco Bay, which was sampled in 2000. Assessment results indicate that only a small percentage of the total area of these estuarine systems has levels of sediment contamination of either metals or organic compounds potentially toxic to benthic organisms. These results were confirmed by a general absence of elevated mortality in sediment bioassays conducted with two amphipod species. Nonindigenous species were present at many sites and were the numerical dominants at several, but overall constituted only ~2% of the total fauna compared to 11% in highly invaded San Francisco Bay (previous studies). Within California's small estuaries, nonindigenous species may be a more widespread form of disturbance to benthic communities than sediment chemical contaminants.