Seed Clam Growth: An Alternative Sediment Bioassay Developed During Emap in the Carolinian Province

摘要: A new sediment bioassay was developed in conjunction with EMAP studies conducted the Carolinian Province using juvenile seed clams, Mercenaria mercenaria. This is a sublethal assay, based on growth (total dry weight) after 7 day incubation period. Seed clam chronic assays were significantly more sensitive than amphipod acute toxicity assays. Optimization components include use of hatchery-reared clams rapid phase, and size-sieving to ensure similar size range. Juvenile not affected by type, i.e., grew well muddy sandy sediments. Clams slightly ammonia amphipods (NOEC porewater total 14 - 16 mg/L for clams). Ammonia concentrations above these levels common reference sites, so most false positives could be explained toxicity. assay possesses number other positive attributes that are desirable bioassay, including requirement relatively small sample (500 ml sediments), balanced sensitivity, low incremental costs, high information gained. The believed valuable tool as monitoring efforts estimating potential