Vertical Migration of Benthos in Simulated Dredged Material Overburdens. Volume I. Marine Benthos.

摘要

This research was conducted to determine the effect of simulated dredged material disposal on the vertical migration ability and survival of benthic invertebrates (Mercenaria mercenaria, Nucula proxima, Ilyanassa obsoleta, Scoloplos fragilis, Nereis succinea, Parahaustorius longimerus, and Neopanope sayi). Depending on the sediment type, sediment measurements of particle size, void ratio, water content, percent silt-clay, and total organic carbon content varied significantly with time and sediment depth. The concentration of dissolved oxygen in the pore water decreased rapidly throughout the experiment; sulfide and ammonia concentrations in the pore water increased the first week and then remained fairly constant throughout the second week; pH and Eh remained essentially unchanged over the same period. Since the surface water chemistry appeared more conducive to the survival of benthic organisms than the pore water chemistry, the organisms may have needed to reestablish direct or indirect contact with the surface waters via siphons, tubes, burrows, etc., through the dredged material overburden.