risk of ammonia toxicity during sediment bioassays with the estuarine amphipod leptocheirus plumulosus

摘要

High levels of ammonia in sediment toxicity tests can potentially confound test results. At issue is whether the observed toxicity is due to elevated ammonia or the presence of more persistent anthropogenic contaminants. To evaluate the risk of ammonia toxicity, information on (1) the exposure-response relationship and (2) the probability of exposure are needed. Preliminary exposure- response data were obtained for two different sieved size classes of the estuarine amphipod Leptocheirus plumulosus representing juveniles (425-600 μm) and subadults (not reproductively active) (600-1,000 μm) in 4-d water-only exposures with ammonia (NH_4Cl).