FISHERY BULLETIN: VOL. 72, NO. 3 



toxic effects. Damage to cell membranes and the 

 cellular contents of planktonic larvae may occur. 

 Goldacre (1968) demonstrated such cytological 

 damage and death to the freshwater protozoan, 

 Amoeba proteus, exposed to crude oil fractions. 

 Brocksen and Bailey (1973) measured increased 

 respiratory response of striped bass and chinook 

 salmon to sublethal concentrations of benzene. 

 The fish recovered to normal activity when they 

 returned to noncontaminated water for several 

 days. Rice and Short were unable to demonstrate 

 changes in the enzyme activity of cholinesterase 

 or Na-K stimulated ATPase in juvenile pink 

 salmon, Oncorhynchus gorbuscha, after in vivo 

 and in vitro exposures to Prudhoe Bay crude oil 

 (Stanley D. Rice and Jeffrey Short, Auke Bay 

 Fisheries Laboratory, NMFS, NOAA, Auke Bay, 

 AK 99821, pers. commun.). This is somewhat 

 surprising because various hydrocarbon pesti- 

 cides have been shown to affect both enzymes. 



Cellular membranes of phytoplankton are also 

 damaged by the penetration of hydrocarbon 

 molecules: the cellular contents are extruded, and 

 oil penetrates into the cell. Detergents adminis- 

 tered in a concentrated solution also penetrate the 

 plant cells and cause the dissolution of cellular 

 membranes and the extrusion of cellular fluid 

 (Ruivo, 1972). The effects of oils on plant respira- 

 tion are variable, but an increase of respiration is 

 frequently observed, probably because of an alter- 

 ation of the mitochondria. This could result in an 

 uncoupling of the oxidative phosphorylation en- 

 zymes from the electron transport enyzmes, and 

 the energy release would be lost as heat. 



All marine animals ultimately depend on the 

 photosynthetic activity of phytoplankton and 

 algae for the production of biomass. Baker 

 (1971), reviewing the literature, noted that 

 weathered Torrey Canyon oil had no apparent ef- 

 fect on the photosynthetic activity of green algae. 

 He did find, however, that green algae treated 

 with fresh crude oil died and that photosynthesis 

 in kelp, Macrocystis sp., was reduced when the 

 kelp was exposed to various petroleum products. 

 Kauss et al. (1973) determined the effects of crude 

 oil on several species of freshwater algae in both 

 field and laboratory experiments. In their field 

 studies, response of the algae to a spill varied from 

 suppression of growth to its stimulation. In their 

 laboratory studies, they noted depressed photo- 

 synthetic rates in one algal species after it had 

 been exposed to aqueous crude oil and other 

 selected aromatics. 



Growth of phytoplankton from axenic cultures 

 and mixed cultures of natural populations was 

 inhibited by water-soluble extracts from no. 2 fuel 

 oil in a laboratory study by Nuzzi (1973). Mironov 

 and Lanskaya (1968) demonstrated that marine 

 phytoplankton vary several orders of magnitude 

 in sensitivity to crude oils and kerosene in oil 

 concentrations ranging from 0.1 to 1,090 ppm. Of 

 the 20 species tested, a diatom, Ditylum 

 brightwellii , was the most sensitive. The wide var- 

 iation in susceptibility may account for the state- 

 ments in other reviews of low toxicity of crude oils 

 to phytoplankton (F0yn, 1965; Nelson-Smith, 

 1970) and supports the premise that biological 

 response will differ among species. 



Sublethal and Chronic Effects 

 of Oil Pollution 



While data are scarce in some of the areas previ- 

 ously discussed, information on the ecological ef- 

 fects of chronic sublethal oil pollution is essen- 

 tially nonexistent. Observing these effects is 

 difficult because they are not dramatic and may 

 pass unnoticed by the casual observer. A full de- 

 scription would require observations extending 

 over a long period of time. 



Lewis (1972), commenting on approaches to the 

 study of chronic pollution, contends ". . . that 

 without a massive expansion of ecological and re- 

 productive data by simultaneous multidisciplin- 

 ary studies not only will we be unable to detect 

 the significant long-term changes, but we will 

 even remain unaware of the most suitable or im- 

 portant species and methods to build into a 

 monitoring program." 



A few studies concerning sublethal effects on 

 organisms have appeared in the literature. Wells 

 (1972) reported deaths of lobster larvae to expos- 

 ures of 0.1 ml of Venezuelan crude oil per liter, 

 while larvae exposed to 0.01 ml/liter had poor 

 survival rates and were unable to molt to the 

 fourth stage. Decreased limb (cirral) activity of 

 marine larvae exposed to oil has been reported 

 (Smith, 1968). Kuhnhold (1972), while observing 

 toxic effects of crude oils to eggs of cod and to 

 larvae of cod, plaice, and herring noted that the 

 larvae exposed to oil-contaminated water were 

 unable to avoid well-defined milky clouds of toxic 

 oil dispersions. Blanton and Robinson (1973) ob- 

 served damage to the gills of specimens of seven 

 species offish that had apparently been exposed to 

 an oil spill off the Louisiana coast. 



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