Contaminated sediment testing with the bivalve Mulinia lateralis: culture refinement for organism availability.
Availability of test species for estuarine benthic assessment is limited; therefore, a method was developed by the U.S. Environmental Protection Agency for using the dwarf surf clam (Mulinia lateralis) to identify adverse biological effects of bulk estuarine sediments. A multilaboratory evaluation of the draft method resulted in favorable responses from the participants with respect to general testing and handling of the clam. However, availability of good-quality test organisms was limited. An investigation of culture techniques determined that culture vessel topography dramatically influenced survival, because larvae accumulated in bottom depressions. Conditioning of brood stock was enhanced by algae naturally containing both 20:5n-3 and 22:6n-3 fatty acids. Survival of larvae to metamorphosis at 14 d postspawn was greatly increased by maintenance at a lighting of 734 lux with addition of gradually increasing amounts of Isochyris galbana and Chaetoceros calcitrans. Greater than 50% survival of 600 juveniles to testing size by 14 d postmetamorphosis was accomplished by intermittent delivery of algae 12 times per day in a total of 13 L of seawater. By 21 d postmetamorphosis, an additional 27% achieved testable size. As a result of identification of these culture parameters, test bivalves can be readily available to improve predictions of adverse biological effects on benthic communities beyond those presently determined through amphipod exposures.
Cripe
Geraldine M
GM
U.S. Environmental Protection Agency, 1 Sabine Island Drive, Gulf Breeze, Florida 32561, USA. cripe.geraldine@epa.gov
D000818:Animals; D049872:Bivalvia / Q000187:drug effects* / Q000254:growth & development*; D046508:Culture Techniques; D004785:Environmental Pollutants / Q000633:toxicity*; D056890:Eukaryota / Q000187:drug effects; D019015:Geologic Sediments / Q000737:chemistry*; D007814:Larva / Q000187:drug effects; D015996:Survival Rate
D004785:Environmental Pollutants