Toxicity of dispersed and undispersed, fresh and weathered oil to larvae of a cold-water species, Tanner crab (C. bairdi), and standard warm-water test species

There are many methods in current use for testing the toxicity of discharges to marine waters. Standard tests and species established by the Environmental Protection Agency and other regulators are commonly used. None of these commonly used test procedures are conducted with cold seawater or species typical of northern latitudes. This paper reports on the toxicity testing of oil and dispersed oil, both fresh and weathered, to larvae of a cold-water species, the Tanner crab (Chionocetes bairdi), and compares these results to those observed with a standard warm-water test species, the saltwater mysid (Mysidopsis bahia). The method of reporting the exposure dose is based on: loading rate (LR), concentrations of volatile organic analytes (VOA, C6–C9), total petroleum hydrocarbon (TPH, C10–C36), or on total hydrocarbon content (THC, C6–C36). Different conclusions result, depending on the reporting method. These differences are chiefly due to the greater accommodation of VOA in the colder water and the paucity of TPH in undispersed cold-water solutions.