The effect of sediment on survival, growth, reproductive success and bioaccumulation in Neanthes: Summary report

Sediments taken from the vicinity of the County Sanitation Districts of Orange County ocean outfall were tested for survival, growth, reproduction and bioaccumulation of toxicants on the polychaete, Neanthes arenaceodentata. The end points were survival, growth (dry weight), reproductive success (as number of emerged larvae) and bioaccumulation (metals, DDT, PCBs). Ten experiments have been conducted over a 2 year period of which 2 measured reproductive success. The experiments for survival and growth utilized 2--3 week old post-emergence juvenile worms and subjected them to different test sediments including an inert sediment and plain sea water control. Worms were fed during the experiments. Experiments for reproductive success and bioaccumulation consisted of placing 100 juvenile worms each in 10 gallon aquaria together with test sediment for a 35--40 day period. After which, 10--15 pairs were made and each pair was placed in a separate 1 liter beaker together with sediment for the reproductive experiment. The remaining worms in each aquarium were used for chemical analysis. No toxic responses, as measured by survival, growth and reproductive success, were noted at any station during the 2 year study. Growth was generally lower in the inert sediment and sea water controls compared to test sediments indicatingmore » that worms were obtaining some nutrients from the sediment. No difference was noted in the number of emerged juveniles in any test container. While worms accumulated metals and organics in their tissue, there was neither a relationship to the station location nor to survival, growth or reproduction.« less