Rejuvenating Fish Stocks
When planning for the construction of wind turbines in The Great Lakes impacts on aquatic life are a foremost concern. Fortunately, in Lake Ontario, where lack of quality spawning habitat is a crucial factor in fish stock decline, wind farm towers are actually good news.
In Lake Ontario, offshore wind turbine foundation could serve to assist in the regeneration of Lake trout and American eel stocks. According to the Ontario Ministry of Natural Resources, the once abundant American eel is in decline. For example, the commercial catch of eel has declined from from approximately 223,000 kg in the early 1980s to 11,000 kg in 2002.
Offshore wind: a proven foundation for new spawning ground
If well-sited, offshore wind farms have been found to be beneficial to fish stocks. Strategically situated foundations, and other in-water structures, are known to create a "reef effect" by sheltering young fry (fish) from storms that roll across the lake. This has been found to regenerate their populations by up to eight times the natural rate (J.M. Casselman, 1995. "Survival and development of lake trout eggs and fry in Eastern Lake Onatrio," Journal of Great Lakes Research)
Another study shows that lake trout prefer small, new areas of artificial substrate such as rock piles to deposit their eggs even when larger natural areas are available within 100 m. This indicates their preference for clean substrate rather than the absence of natural substrate nearby. The study suggests that the foundations of turbines positioned in shallow water, such as those of Trillium Power Wind 1, will actually provide new spawning ground for fish and could substantially improve some species’ reproductive success (J.E. Marsden et al. 1995. "Recognition of spawning areas by lake trout: Deposition and survival of eggs on small, man-made rock piles," Journal of Great Lakes Research)
The most recent international study corroborating the "reef effect" observed in The Great Lakes found that turbine foundation acted as habitats for a wide variety of sea life including: fish, crabs, mussels, lobsters and plants. The study, conducted by scientists at Stockholm University's Zoology Department, found that offshore wind turbines acted as artificial reefs and helped create a more diverse and dense population of marine life than found at control sites far from the wind farms.