This analysis of the primary biological effect of potential offshore oil spills resulting from hypothetical oil production was commissioned by the Council on Environmental Quality as part of its studies on oil exploration and drilling on the Atlantic and Alaskan continental shelves. Qualitative predictions of physical, chemical, and biological effects of oil on differing coastal habitats and natural communities are based on the probability of accidental spills, spill trajectories, and the behavior of oil in marine ecosystems. An environmental inventory describes Atlantic coast habitat types and lists selected important species. Lack of data on Alaskan habitats prevents a comprehensive biological analysis of oil spill effects. A spill's initial ecological impact depends on the amount, composition, and distribution of the oil, and the sensitivity of the ecosystem's organisms to it. To individual organisms, oil may be toxic or tainting by coating or hydrocarbon accumulation in tissues; alteration of the substrate by oil deposition may exclude species from their normal habitats. Persistence of the oil depends on the physical variables which control the degradation processes of evaporation, dissolution, microbial and chemical or light oxidation. Persistence rates in different habitat types are estimated from documented spills. Biological recovery times for species suffering 100% mortality vary with the species' dispersal strategies and fecundity; anadromous fish may also be vulnerable to oil. Habitat recovery times cannot be accurately predicted because of lack of data on the recovery times of different species. Oil spills from hypothetical Atlantic offshore platforms in the Baltimore Trough and on Georges Bank are expected to have little or no significant biological effects at the population level, while spills from drilling sites in the Georgia Embayment pose relatively higher environmental risks. Because little ecological data exists for the Gulf of Alaska, conclusions on spill effects in this area are highly uncertain. Nearshore spills from terminals (three hypothetical Atlantic coast sites), which could beach in 0-2 days, would cause high mortality to most exposed species.

  • Supplemental Notes:
    • Report to Council on Environmental Quality. Index No. 74-819-Cwm.
  • Corporate Authors:

    Massachusetts Institute of Technology

    Sea Grant Program, 77 Massachusetts Avenue
    Cambridge, MA  United States  02139
  • Authors:
    • Moore, S F
    • Chirlin, G R
    • Puccia, C J
    • Schrader, B P
  • Publication Date: 1974-4

Media Info

  • Pagination: 205 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00057123
  • Record Type: Publication
  • Source Agency: Massachusetts Institute of Technology
  • Report/Paper Numbers: MITSG 74-19
  • Files: TRIS
  • Created Date: Jul 31 1974 12:00AM