329 



tivity. However, such feeding activity does concentrate hydrocarbons in organisms 

 that in turn are eaten by larger animals and the oil thus enters the food chain. 

 Large amounts of tar were found in the stomachs of three saury, Scomberesox 

 saurus. from a sample of ten in the Mediterranean Sea near Gibraltar by Horn, 

 efc al (1970, p. 246). Although the.se authors note that the saury is said to feed 

 ui>on small crustaceans and perhaps upon small tish, they also note that "vege- 

 table debris" was found in the stomach of one saury, which suggested the species 

 is not a very discriminate feeder. Tliey point out, however, that because this 

 fish is fed upon by porix)ises and larger predaceous fishes, a direct introduction 

 into the ocean food web of material known to be toxic occurs. Mironov (1968, p. 



336) notes the ability of some zooplankton organisms to accumulate hydro- 

 carbons, assuring exposure at all trophic levels. 



Some doubt may remain as to the direct carcinogenicity of crude oil and crude 

 oil residues in marine organisms according to Blumer (1969, p. 9) but evidence 

 pointing toward this is accumulating (Blumer, 1970, p. 4). A literature search 

 and evaluation conducted for the U.S. Coast Guard by Battelle Memorial In- 

 stitute (1967. pp. (>-19) noted that shellfish, although alive, may be unfit for 

 consumption because of the carcinogenic hydrocarbon 3, 4-benzpyrene found in 

 their bodies. Oysters that were heavily polluted and contaminated with ship 

 fuel oil were also reporte<l to contain 3, 4-benzpyrene. The Battelle review also 

 reported barnacles attached to creosoted poles located in marine waters contained 

 the same carcinogenic hydrocarbon (3, 4-benzpyrene), and it elicited sarcomas in 

 mice when extracts from the barnacles were injected into the mice. The endemic 

 occurrence of papillary tumors around the rectal opening of soft shell clams 

 {Mya arcnaria) was reported, but the author (Battelle Memorial Inst., 1967, 

 pp. 6-19) did not feel these were due to oil pollution, even though the clams were 

 taken from waters adjacent to areas highly polluted by ship fuel oil. 



Aggregations of the planktonic forms of many pelagic and benthic organisms 

 wcur in the surface layer of the sea. This community of the surface T) cm., the 

 neuston, is the first affected by oil entering the water. Many planktonic larvae 

 are phototrophic at their earliest stages and concentrate in this layer. Organisms 

 in these early development stages appear most sensitive to oil pollution, coinci- 

 dently with their ix'riod of greatest exposure. 



Studies by Mironov (19(5S, p. 336) on the development of fertilized eggs of the 

 plaice (Rhotnbus macoticufi) showed extreme sensitivity of the eggs to the influ- 

 ence of oil products present in seawater. He noted that injury to the eggs occurred 

 at concentrations of 10'^ to 10"° ml/1 (0.1 to 0.01 ppm). In these concentrations 

 of oil products. 40 to 100 percent of the hatched pre-larvae .showed some signs of 

 degeneration during development and perished. Mironov (1969a) also demon- 

 strated that 1 ppm crude oil was toxic to the eggs of anchovy, scorpion fish, and 

 sea parrots from the Black Sea. 



Larvae of Elinius niodcfttus, an AiLStralian barnacle introduced to Europe, are 

 tolerant of 100 ppm crude oil but show a delay in .setting of the cyprids (the 

 final larval stage), while adults of this species can tolerate higher concentrations 

 but show reduced activity at 100 ppm (Corner, et al, 1968). Mironov (1968, p. 



337) reported that experiments with adult and post-larval stages of barnacles 

 (Balanus sp.) showed the latter to be a hundred times more sensitive to oil 

 pollution than the adult forms. 



Decreased limb (cirral) activity of marine larvae exposed to oil has been 

 reported (Smith. 1968, p. 135). Irreversible damage to cell membranes and granu- 

 lar contents of planktonic larvae may also occur. Goldacre (reference in Arthur, 

 1968, p. 161) has demon.strated such cytological damage and death to the fresh- 

 water protozoan. Amoeba prntcua, exposed to crude oil fractions. 



Mironov (1968b) tested crude oils on several copepods and a cladoceran. finding 

 1 ppm killed all forms within less than. a day. Acartia and Calanus were reported 

 (Mironov, 1968, p. 336) to succumb to 0.01 ppm oil in seawater in 72 to 96 hours. 

 Although surviving longer than copepods, larvae of crab and shrimp al.so die at 

 1 ppm (Mironov, 1969c). Two of the copepods tested, Acartia clausi and Para- 

 calanus par\:us, occur in Alaskan waters. 



Mironov and Lanskaya (1968) demonstrated that marine phytoplankton vary 

 several orders of magnitude in sensitivity to crude oils and kerosene. Of the 20 

 species they tested (in oil concentrations ranging from 0.1 ppm to 1,090 ppm) 

 Dityhim brightwcllii, a diatom occasionally found in Alaska, was the most .sensi- 

 tive. The wide variation in su.sceptibility may account for the .statements of low 

 toxicity of crude oils to phytoplankton found in other reviews (Foyn, 1965 ; Davis, 

 1970; Nelson-Smith, 1970). 



