ABSTRACT
The sensitivities of 39 subarctic Alaskan species of marine fish and invertebrates to water-soluble fractions of Cook Inlet crude oil and No. 2 fuel oil were determined. This is the largest group of animals ever tested under similar test conditions with the same petroleum oils and analytical methods. Organisms bioassayed represent several habitats, six phyla, and 39 species including fish (9), arthropods (9), molluscs (13), echinoderms (4), annelids (2), and nemer-teans (2). Sensitivities were determined by 96-hour static bioassays. Concentrations of selected aromatic hydrocarbons were determined by gas chromatography; concentrations of paraffins were determined by infrared spectrophotometry.
Although sensitivity generally increased from lower invertebrates to higher invertebrates, and from higher invertebrates to fish, sensitivity was better correlated to habitat. Pelagic fish and shrimp were the most sensitive animals to Cook Inlet crude oil with 96-h median tolerance limits (TLm's) from 1–3 mg/l total aromatic hydrocarbons. Benthic animals, including fish, crabs, and scallops were moderately tolerant (TLm's to Cook Inlet crude oil of 3–8 mg/l total aromatic hydrocarbons). Intertidal animals, including fish, crabs, and starfish, and many molluscs, were the most tolerant forms to water-soluble fraction of petroleum (TLm's greater than 8–12 mg/l of total aromatic hydrocarbons). Most of the intertidal animals were not killed by static oil exposures. No. 2 fuel oil was more toxic to most species than Cook Inlet crude oil.
Sensitive pelagic animals are not necessarily more vulnerable to oil spills than tolerant intertidal forms — oil may damage intertidal environments more easily and adverse effects may persist longer than in damaged pelagic environments.
