Oil in the Sea Inputs, Fates, and Effects (1985) / Chapter Skim
Currently Skimming:
EXECUTIVE SUMMARY
EXECUTIVE SUMMARY
Pages 3-16
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From page 3... ...
The modern influx of petroleum into the marine environment is on a different scale, occurring more rapidly and over a wider area, and probably is of a different k ind . The product enter ing the oceans today, both from chronic effluent release and runoff and from sudden catastrophic spills, represents a sudden and significant input of contaminants when viewed against the much longer, but much lower, continuous presence of seepage petroleum.
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From page 4... ...
Inevitably, the potential impact of petroleum as part of, or together with, other contaminants in the marine environment was considered. While in some instances petroleum itself is readily seen as the identif table pollutant, as for example, in tanker spills or in known cases of chronic petroleum pollution, there are many regions where petroleum hydrocarbons are thought to form part of a more general pollution threat to the health of those environments.
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From page 5... ...
The analysis of petroleum hydrocarbons, pyrogenic hydrocarbons derived from the atmosphere and resulting from incomplete combustion of oil, coal, wood and gas, products of metabolic alteration of petroleum by organisms, and products of chemical and biochemical transformation after oil enters the sea (e.g., metabolites and photochemical oxidation products) , has made great strides, especially with the parallel development of glass capillary gas chromatography, highpressure liquid chromatography, and glass capillary gas chromatography/ mass spectrometry computer systems.
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From page 6... ...
FINDINGS AND RECOMMENDATIONS Major Findings The authors of this report conclude, based upon the evidence available, that there has been no evident irrevocable damage to marine resources on a broad oceanic scale, by either chronic inputs or Occasional major oil spills. However, specific information that would enable unequivocal assessment of the impact of oil on the environment does not yet exist, particularly, with regard to certain specific environments and conditions.
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From page 7... ...
In reviewing the past 10 years, it is probably fair to say that these years have yielded a much improved understanding of the general impact of petroleum on the marine environment. Furthermore, we conclude on the evidence available that there has been no evident irrevocable damage to marine resources on a broad oceanic scale, by either chronic inputs or occasional major oil spills.
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From page 8... ...
The difference (decrease) between that earlier estimate and the current best estimate of 3.2 mta does not necessarily represent a decline in annual input of petroleum hydrocarbons into the marine environment during this period but indicates a better estimating of individual inputs.
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From page 9... ...
products of chemical and photochemical alteration after oil enters the oceans; and (3) pyrogenic hydrocarbons produced during combustion of oil, coal, and other carbonaceous materials.
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From page 10... ...
Major Finding For all these processes, the relationship between chemical composition and the formation and stability of oil-water emulsions and of the sorption characteristics between oil and organic particulate matter are only poorly known. If there is to be a better understanding of the physical and chemical behavior and fate of petroleum hydrocarbons in the marine water column, then more basic research and experimentation in this area are needed.
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From page 11... ...
In many cases, as in low level contamination, metabolic degradation and/or the clearing of petroleum from the tissues back to the water can balance uptake, without significant bioaccumulation of these compounds in the tissues. Microbial degradation is a major clearing mechanism for removal of petroleum pollutants from marine environments.
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From page 12... ...
Petroleum hydrocarbon contamination (PHC) of marine sediments parallels that for the water column, with PHC concentrations directly related to the proximity of sewage and industr ial outfalls, dumping sites, and accidental discharges .
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From page 13... ...
The polar environment poses a special problem because of almost year-round ice cover and relative inaccessibility, compounded by large gaps in the basic data base on polar biology. While some information exists on oil and the polar environment, the potential impact of a major oil spill on polar ecosystems cannot be estimated with confidence at this time.
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From page 14... ...
of petroleum hydrocarbons can apparently interfere with the normal behavior of marine organisms, especially the more fragile components such as the larval and juvenile forms of the marine foodchain. Continued study of a few key examples of recovery after oil spills or from well-defined chronic input sources, with adequate controls, is essential if ecosystem effects and their economic significance are to be well-defined.
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From page 15... ...
and when the oil is weathered. It is also revealing that, of the petroleum hydrocarbons entering the marine environment, an estimated 39% derives directly from oil and gas production and transportation.
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From page 16... ...
There is a clear need to continue research on these local situations, not only because of the intrinsic toxicity of petroleum, but also because of its poorly understood but suspected synergistic impact with other contaminants. Particular concern is expressed about the potential impact of oil on tropical coastal environments -- mangrove systems and coral reefs.
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