Chronic Sublethal Effects of San Francisco Bay Sediments on Nereis (Neanthes) Arenaceodentata: Non treatment Factors

: Initial development of a chronic sublethal sediment bioassay with the polychaete Nereis (Neanthes) arenaceodentata is described. The test was initiated with 2to 3-week-old postemergent juvenile worms and terminated after 21 days. The sublethal test end point was estimated individual somatic growth rate (milligrams dry weight/day). The potential bias due to selected nontreatment factors on polychaete survival and growth was evaluated. For example, grain size had no effect, while the number of worms added to each exposure vessel was critical. Direct transfer from 30 ppt to salinities or = mg/L ammonia or > or = mg/L hydrogen sulfide.... Chronic, Growth, Neanthes, Sediment, Sublethal.