skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Toxicities of crude oils and oil-dispersant mixtures to juvenile rabbitfish, Siganus rivulatus

Journal Article · · Trans. Am. Fish. Soc.; (United States)
 [1];
  1. National Marine Water Quality Lab., Narragansett, RI

Toxicities were determined for two crude oils, one from the Persian Gulf (Iran) and one from the Sinai Peninsula (Gulf of Suez), to rabbitfish, Siganus rivulatus, an economically important species of teleost from the Red Sea. Also tested for toxicity were ST 5, a chemical oil dispersant, and oil-ST 5 mixtures in the ratio 10:1 vol/vol. Static tests conducted in small (3-liter) jars at 41 /sup 0///sub 00/ salinity and 23/sup 0/C produced LC/sub 50/ (168 h) values of 0.74 ml/liter for Iranian crude, 14.5 ml/liter for Sinai crude, and 0.010 ml/liter for ST 5; LC/sub 50/ values for oil-ST 5 mixtures reflected biocidal properties of ST 5 alone. Iranian oil became less toxic with increasing time in seawater over a period of 168 hours; the reverse was observed for Sinai crude. ST 5 exhibited a dramatic reduction in lethality after 2 hours in the assay medium. The most toxic component tested of Iranian crude was the lowest-boiling fraction; with Sinai crude it was the highest-boiling fraction; with ST 5 the volatile surfactant component accounted for almost all deaths. Liver enlargement in rabbitfish was linked with exposure to comparatively high concentrations of crude oil. High sublethal levels of ST 5 caused reductions in blood hematocrit. Rabbitfish survival at a given petrochemical concentration was highest at intermediate salinities of 30-50 /sup 0///sub 00/ in the salinity range tested of 20 to 60 /sup 0///sub 00/. Rabbitfish were more resistant to crudes and oil-dispersant mixtures in continuous flow bioassays conducted in large tanks than in static jar bioassays. Tank tests also suggested that mortalities were higher among toxicant-stressed fish confined 0.2 to 1.0 meters from the surface than among fish held 1.0 to 1.8 m from the surface. (auth)

OSTI ID:
7364814
Journal Information:
Trans. Am. Fish. Soc.; (United States), Vol. 104:3
Country of Publication:
United States
Language:
English