With increasing use of offshore and estuarine facilities for production, handling, and transportation of refined and crude oil products, the potential for ecological destructive spillage is greatly enhanced. Restoration of damaged habitats previously has been limited to mechanical and chemical cleanup, with biological devastation left to natural recovery. However, the long time periods necessary to achieve successful ecological recovery must be shortened to allow for maximum utilization of local sport are commercial fisheries, wildlife and waterfowl resources, and water-oriented recreation.
Estuarine habitats may be greatly impaired by large quantities of spilled oi1 due to the toxic aromatics and water-soluble fractions, emulsification of oil, and adsorption of oil into sediments. High initial mortality may completely eliminate sensitive benthic and intertidal faunas, or, if incomplete, drastically alter the existing species diversity and community stability. Repopulation will be hindered by lack of adequate food resources, residual sediment toxicity, lack of clean substrate for larval attachment, and the seasonal abudance of immigrating juvenile and larval forms.
Actual restocking of recently captured or cultivated organisms may become necessary in areas of greatest impact, such as spawning and nursery grounds. Certain species, i.e. penaeid shrimp post-larvae, oysters, blue crabs, and various estuarine fish, may be obtainable through private companies and federal, state, or university fishery labs, particularly those involved in mariculture research. Direct additions of selected organisms may circumvent various successional stages in the recovery process, and restore estuarine ecosystem balance more quickly. Depressions in future landings of commercial valuable crustaceans, shellfish, and finfish may also be minimized due to the timely enlargement of potential breeding and seed stock.
As the negative effects of oil spillage came to the public's attention following the Torrey Canyon disaster, the development of cleanup devices and procedures to counter the potential environmental damages was necessary to protect this oil-oriented country's aquatic resources. An expanded concept of ecological restoration arose as a natural sequel to the physiochemical removal of the offending substance. With a more rapid return to pre-spill conditions as its goal, biological rehabilitation through direct introduction of key species into the disturbed habitat may also positive to be a useful technique for mitigating oil spill damages.
Restoration in this discussion includes those post-cleanup activities which aid in the ecological recovery of an oll-d1srupted area. Ecological recovery responds direct to the success of oil cleanup activities, particularly the degree of environmental detoxification achieved. However, specific cleanup practices, especially the extensive use of surfactants or emulsifiers, can increase overall spill toxicity and further hinder reputation of the resultant biological wasteland. Mechanical and chemical removal techniques for removal of crude and refined oils may not be technically or economically feasible under some conditions. Biological methods using oil-degrading bacteria prove beneficial in facilitating recovery after these "uncleaned" spills. In all these cases, artificial repopulation techniques should be able to accelerate natural recovery.