GUT CONTENTS - A SIGNIFICANT CONTAMINANT OF MYTILUS-EDULIS WHOLE-BODYMETAL CONCENTRATIONS

Ingested matter can have a significant effect on whole body metal conc entration measurements in Mytilus edulis. Depuration of mussels in cle an seawater for 36 h prior to dissection eliminates most of these cont aminating gut contents. Depuration followed by metal analyses is the m ost direct method of determining mussel tissue metal bioburdens. After being transplanted into a plume of primary treated sewage effluent in Salem Harbor, Massachusetts for 32 days, Al, Cr, and Fe concentration s in depurated mussels were significantly lower than those determined for either non-depurated mussels or for depurated mussels to which fec al concentrations of Al, Cr, and Fe were added back in. Although mathe matical methods developed by both Ouellette (1978) and Boehm et al. (1 988) could be applied to non-depurated mussels in order to correct for errors associated with gut metal contamination, these indirect method s were not as reliable as depuration prior to analysis.