WP20 Contaminated Harbor and River Sediment
Wednesday, 16 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(MOR-1117-841112) Responses of Five Benthic Organisms to Marine Sediments from Former Operating Pulp Mills.

Mortensen, L¹, Hummell, R¹, ¹ Malcolm Pirnie, Seattle, WA, USA

ABSTRACT- Marine sediments near previously operating pulp mills in Sitka, Alaska and Port Angeles, Washington were evaluated for benthic toxicity. Multiple laboratory bioassays were used as part of these evaluations. Subchronic toxicity measured by survival over 10 days was evaluated and observed in the amphipod Rhepoxynius abronius. Chronic toxicity measured by survival for 28 days, and reproductive success were evaluated, but not observed in L. plumulosus. Myitilus edulis larvae were evaluated for survival and developmental normality and effects were observed near the mill. Chronic effects of Neanthes arenaceodentata were evaluated based on growth of the polycheate for 28 days. Reduced growth was observed. Echinoderm larvae (Strongylocentrus purpatus) development was also evaluated using a suspended phase test to assess the effects of colloidal and very fine particulate material on pelagic organisms in the water column. During these tests, a slurry of the sediment was created, and the organisms were exposed to water columns containing 10%, 50%, and 100% suspended phase particulates. Reduced development was observed at exposures to 50% and 100% suspended phase particulate exposure. Several persistent organic pollutants were detected in the sediments evaluated. Additionally, toxic effects were generally observed in the depositional areas near these facilities where organic carbon levels had been increased significantly, and ammonia concentrations evaluated during the tests were a significant cause of some of the observed mortality. Degradation of wood debris in the marine environment also produced levels of resin acids, guiacols, and phenols that were associated with much of the observed mortality after the influence of ammonia was removed. The relationship of chemical concentrations in the test sediments and the bioassay results is presented with a correlation analyses.