CHRONIC EFFECTS OF ORGANOCHLORINE EXPOSURE IN SEDIMENT TO THE MARINE POLYCHAETE NEANTHES ARENACEODENTATA

Organisms exposed to organochlorinated compounds in sediments are like ly to suffer chronic rather than acute effects. Thus, acute toxicity t ests are unlikely to truly assess their potential impact. A 120-d toxi city test was designed to assess the impact of organochlorine exposure (polychlorinated biphenyl and dichlorodiphenyltrichloroethane) on the marine polychaete Neanthes arenaceodentata. A two-tiered approach was used: Tier I involved reference sediment spiked with a range of conce ntrations of the two organochlorines bracketing the concentrations fou nd in natural sediments, and tier II involved field sediments collecte d from a coastal area contaminated with high concentrations of the sam e two organochlorines. Testing measured a number of endpoints, includi ng survival, growth, and reproduction. Survival and growth were unaffe cted in either tier by any of the test sediments. Reproductive endpoin ts, however, were depressed in both tiers relative to the reference se diment.