Field Verification Program (Aquatic Disposal). Sister Chromatid Exchange in Marine Polychaetes Exposed to Black Rock Harbor Sediment

This report evaluates the use of the cytogenetic technique of sister chromatid exchange (SCE) to measure potential mutagenic activity associated with contaminated dredged material. The three primary objectives were to test the applicability of the SCE technique, to field verify any responses observed in the laboratory, and to determine the degree of correlation between the bioaccumulation of contaminants and the SCE response. This project was part of the US Environmental Protection Agency/Corps of Engineers Field Verification Program (FVP). The SCE technique was applied to Nephtys incisa, an infaunal polychaete dominant in the benthic community at the Central Long Island Sound (CLIS) disposal site. The SCE response was measured in N. incisa exposed to suspended and bedded sediment phases of Black Rock Harbor (BRH) dredged material in the laboratory. The treatment employing suspended BRH sediment over bedded reference sediment was significantly higher than all other treatments. BRH sediment contains high concentrations of many contaminants including polychlorinated biphenyls (PCBs) and polynuclear aromatic hydrocarbons (PAHs) that accumulate in tissues of worms exposed in both the laboratory and the field. Of ten chemicals and two summary statistics analyzed for correlation between SCE response and tissue concentrations, only two, benzo (a) pyrene (BaP) and chromium, are known mutagens. Prepared in cooperation with Science Applications International Corp. Narragansett, RI.