Letters

Aquaculture in Offshore Zones

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Science  22 Dec 2006:
Vol. 314, Issue 5807, pp. 1875c-1876c
DOI: 10.1126/science.314.5807.1875c

The Editorial by Rosamond Naylor, “Offshore aquaculture legislation” (8 Sept., p. 1363), suggests that the motivation for moving aquaculture into the open ocean is that “marine fish farming near the shore is limited by state regulations.” Although unworkable regulations may exist in a few states, in the larger scheme this is irrelevant. Of the offshore aquaculture projects currently under way, none are occurring in the U.S. Exclusive Economic Zone (EEZ); rather, they are happening in state waters. Even historically, only two aquaculture projects have ever occurred in federal waters (1).

Much of Naylor's stated concern over offshore aquaculture is based on historical experience with near-shore fish farms. This is in spite of years of more relevant offshore operations that reveal little, if any, negative impact on the environment or local ecosystems (2, 3). Naylor criticizes the National Offshore Aquaculture Act of 2005 because it lacks specific environmental standards. Yet, she recommends California's recent Sustainable Oceans Act as a legislative model, although it is similarly silent, leaving those details to rule-making in response to the best available science.

Naylor criticizes the use of fishmeal as an aquaculture ingredient, ignoring the fact that industrial fisheries are well managed and would occur with or without aquaculture's demand. Naylor ignores the higher efficiency of using fishmeal to feed fish compared with its use in land-based livestock operations (4). Also ignored is the inefficiency of using small pelagic fish in the natural setting to feed predator fish (5).

Researchers and entrepreneurs currently developing the technologies needed for offshore aquaculture share a vision of a well-managed industry governed by regulations with a rational basis in the ecology of the oceans and the economic realities of the marketplace.

References and Notes

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In her provocative Editorial “Offshore aquaculture legislation” (8 Sept., p. 1363), R. Naylor raises valid points regarding regulation of oceanic aquaculture, since it is sure to grow in the future because of dwindling global fishery supplies. This growth is bound to bring with it many possibilities for resource and environmental degradation. The whole prospect reminds me of my research with a group of entrepreneurs more than a decade ago into the possibility of coupling offshore oil and gas production with operations designed to farm fish and shellfish in deep water. The idea was to establish mariculture (sea farming) technologies that would utilize offshore oil and gas production platforms located in the clear, oceanic-quality, deep waters of the Gulf of Mexico, beyond near-shore land runoff and related pollution.

The economic incentives for such a plan included the fact that when oil and gas production rigs are near the end of their life, it is more economically prudent to cease production because of the excessive costs of drawing additional resources. After useful life, the production companies are also required by U.S. law to remove the oil and gas structures from their deep water settings.

These platforms have usually supported an extensive, highly productive underwater ecosystem of attached and foraging marine life that is not only important for its inherent natural value but also important economically to tourism and recreational fishing. Our investigations in the early 1990s focused on maintaining these ecologically important environments while capitalizing on their economic value by designing vertically integrated mariculture operations for spawning, cultivation, harvesting, processing, and sale of marine species that would be based on the rig infrastructure.

The concept of utilizing offshore oil and gas production platforms for mariculture purposes is not new. If the legislative concerns for offshore mariculture expressed by Naylor can be met, imagine the possibilities for this technology in food production. The use of offshore oil and gas platforms for growing fish offers a way to turn the liabilities of an energy production business into assets, continuing the sustainable economic life of these platforms as well as their ecological and societal importance.

Response

My Editorial emphasized the need for environmental safeguards in the drafting of the National Offshore Aquaculture Act (S.1195). Unlike near-shore aquaculture, the farming of fish in the open ocean occurs in marine environments with rapid currents, high flushing rates (rapid currents), and minimal interference with other human activities. It is for these reasons, perhaps, that Goudey objects to the comparisons between near-shore and offshore farming in justifying the need for stronger environmental language in the current bill. However, it is misleading to suggest that there are no environmental impacts from offshore fish farming. Very few offshore facilities currently operate at a commercial scale. Therefore, the cumulative impacts on the benthic environment, on the surrounding environment through chemical discharge, and on wild fish populations through genetic and competitive interactions and the spread of pathogens have not yet been demonstrated for the type of intensive, industrial production that would be made possible through S.1195. There is evidence from existing offshore operations of predator attacks (1, 2), farm fish escapes (24), and high fishmeal and fish oil use in feeds (5). Although livestock also uses fishmeal and fish oil in feeds, these ingredients are more essential for many aquaculture species. Moreover, aquaculture's use of fishmeal and fish oil is expected to increase in the future and does not represent a balanced, ecologically sound use of these resources. Contrary to Goudey's statement, there is little evidence that industrial forage fisheries are now well managed throughout the world.

CREDIT: KEN HAMMOND/USDA

There are some existing commercial farms operating several miles offshore within state boundaries that have demonstrated strong environmental stewardship. My Editorial recommended that business leaders from these operations become engaged in a redrafting of the bill; such leaders would certainly promote environmental safeguards and would have no problem operating profitably under stronger legislation. Flint's Letter reinforces this idea and suggests that offshore oil and gas platforms be used for mariculture activities—provided that they meet the environmental requirements of a stronger national legislation. I commend Flint's confidence that aquaculture can proceed under more rigorous environmental standards. For offshore platforms to be used for aquaculture, however, additional approval must be sought through the Department of the Interior in connection with the Outer Continental Shelf Lands Act.

Finally, I recommended environmental language similar to that found in the California Sustainable Oceans Act (SB 201) for the revision of the national bill. The California legislation incorporates many features that the national bill does not, including the requirement of environmental impact assessments before granting of leases, stronger language (e.g., minimize escapes, disease transfers, and pollution, rather than just “consider” these potential impacts), and transparent oversight and public participation in the process. As the rule-making process is set to begin, California is now in a position to ensure that any marine aquaculture facilities operating in state waters will be environmentally sound. Whether open ocean aquaculture develops within state boundaries or in federal waters, the legislative process should incorporate environmental safeguards to protect marine ecosystems for all species—not just humans—in the long run.

References

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