The Department of the Interior's (recently reorganized) Minerals Management Service has studied the effects of using decommissioned oil and gas rigs in the Gulf of Mexico as habitat for marine species for almost 30 years. Turns out they provide a remarkably fecund environment:
Whether it’s an operating oil and gas (petroleum) production platform or a retired platform intentionally placed for conservation and fisheries enhancement, a typical 4-pile platform jacket (the underwater support structure of an offshore platform) provides 2-3 acres of living and feeding habitat for thousands of underwater species.As with petroleum platforms, so too with offshore wind or other renewable ocean energy platforms. For years commercial and sports fishers have resisted any advance in offshore renewable energy structures and have provided a litany of fears regarding how fish and crab populations would be decimated. It seems unlikely, however, that submerged species will much care what's on top of the platform, above them, out of the water. And unless they feed on spilled hydrocarbons, the lessened pollution from renewable energy rigs would also be a plus.
Petroleum platforms function as entirely new places to live; niches for countless animals. In addition to harboring numerous species of juvenile fish and adult life stages, these platforms serve as hunting grounds for swift open-ocean pelagic fishes, such as mackerel, tuna, and jacks. These fish species use the steel platform reefs as places to grab a quick meal, but also for orientation in an otherwise featureless environment, and as areas to rest where the platform structure weakens or deflects currents, and as places to hide from species that may prey on them. Marine researchers have reported fish densities to be 20 to 50 times higher at oil and gas platforms than in nearby open water, and each platform seasonally serves as critical habitat for 10 to 20 thousand fishes, many of which are of recreational and commercial importance.
Fishing objections to offshore renewable energy platforms, such as those used for wind turbines, must be supported by facts, not fears. The onus should be on those who oppose, since decades of studies seem to provide an existence proof that there is little harm, and arguably some benefit.