Utilitv of a Full Life-Cycle Copepod Bioassay Approach for Assessment of Sediment-Associated Contaminant Mixtures

摘要

CHARLES E. KOVATCH;G. THOMAS CHANDLER;BRUCE C. COULLWe compared a 2l day full life-cycle bioassay with an existing l4 day partial life-cycle bioassay for two species of meiobenthic copepods, Microal. thridion littorale and Amphiascus tenuiremis. We hypothesized that full life- cycle tests would better simulate chronic exposures to copepods and provide more sensitive and realistic infor- mation about contaminant effects on growth of copepod populations. Copepods were exposed to sediments from two sites, non-contaminated North inlet Estuary (NIE), SC (USA), and highly contaminated Shipyard Creek (SYC), SC, and measured for lethal and sublethal test points. Fourteen and 2l day bioassays showed similar negative effects in SYC sediments for both species. Sur- vival and reproductive success were higher in the l4 day than in the 2l day bioassay for both species, in both sediment types. The lower 2l day overall response was not indicative of enhanced bioassay sensitivity. The l4 day bioassay provides sufficient .h generation information to detect negative population level responses to contaminant mixtures.