Interlaboratory assessment of marine bioassays to evaluate the environmental quality of coastal sediments in Spain. V. Whole sediment toxicity test using juveniles of the bivalve Ruditapes philippinarum

Abstract

Several species of bivalves and procedures have been used to characterize sediment toxicity. Here we report the results of an interlaboratory exercise that included three different laboratories to evaluate the use of the bioassay using the commercial clam Ruditapes philippinarum. Six different dredged sediments were studied using two different endpoints: lethality after two different exposure periods (7 and 14 days) and burrowing activity after 48 h of exposure. The lethal endpoint was only sensitive to characterize samples with high metallic concentration and following the 14-day exposure period. The burrowing activity showed very variable results that evidence the unsuitability of this endpoint for dredged material characterization. According to these results, a new design is recommended for the test using juvenile bivalves if it is to be used to characterize sediment samples on a regulatory context especially if sediments are not affected by metallic contamination.