Development of an estuarine sediment burrowing bioassay for shipboard use

A rapid estuarine sediment bioassay based on the burrowing speed of the commercial euryhaline soft-shell clam, Mya arenaria has been extensively tested in the laboratory. With estuarine sampling cruises of several days to a week, this rapid bioassay on shipboard with freshly collected sediments might be useful in determining sites with in situ toxicity where additional synoptic sampling should be made for biological and chemical components of the Sediment Quality Triad, such as community structure and chemical contaminants. Because it was not known whether the M. arenaria laboratory bioassay test could be adapted to shipboard where there is vibration and varying conditions such as sample euryhalinity, it was decided to take this test to sea. This report describes modifications of the bioassay resulting from attempted use on a week-long US Environmental Protection Agency cruise. This cruise collected and analyzed sediments from the Chesapeake and Delaware Bays and ocean dump sites, with salinities ranging from 2 to 32 ppt.