of immediate ecological effects and ecosystem recovery. In this way, the type and dosage of oil, as well as several other factors, can be controlled. This does not mean that accidental spills should not be investigated—even on a shoestring basis—for considerable knowledge can be derived from these studies, and they are the ultimate testing grounds for experimental conclusions.

The effects of chronic or multiple pollution by oil need increased attention. Detailed ecological investigations should be undertaken in ecosystems receiving refinery and sewage hydrocarbon wastes and in oil ports. Estuarine ecosystems already under stress deserve special attention because of their importance to coastal productivity. This problem seems especially pertinent in light of increasing oil imports and the demand for new coastal refinery capacity.

Experimental research is needed on the sublethal effects of oil on marine organisms, including effects on photosynthesis, metabolism, reproduction, behavior, and chemical reception.

The uptake, retention, and release of petroleum hydrocarbons by marine organisms should be further studied. Background levels of "natural" and petroleum-derived hydrocarbons need quantification and qualification. Mechanisms of uptake, metabolic fate, and release are ill-studied. Knowledge of the persistence of various hydrocarbons in organisms and the non-living parts of the biosphere is required.

The threat of oil pollution to human health needs further study and evaluation. Carcinogenic contamination of fishery organisms deserves special attention.

Finally, much of the lack of understanding about the effects of oil pollution stems from our lack of understanding of marine ecosystems. More baseline information is needed against which the effects of pollutants of all kinds may be measured.