

Image: NREL

Doing More With What We Have

Dan Wilhelmsson of the Department of Zoology at Stockholm University recently published a dissertation showing that the underwater foundations of offshore wind and wave farms can be beneficial to marine life, creating artificial reefs that increase the number of fish and crabs. This isn't totally new information, but it's good that we're studying it in more details. But what really caught my eye in the report, though, is that it's possible to tweak these sea-bed anchors to make them more hospitable to marine life. Now that is a great opportunity!

There's little doubt that in the coming decades many offshore wind farms and wave farms will be built all around the world, and it's also painfully obvious that our battered oceans need marine protected areas and new reefs to regenerate themselves to a healthy state.

"Hard surfaces are often hard currency in the ocean, and these foundations can function as artificial reefs. Rock boulders are often placed around the structures to prevent erosion (scouring) around these, and this strengthens the reef function," says Dan Wilhelmsson. [...]

Wave power foundations, too, constituting massive concrete blocks, proved to attract fish and large crabs. Blue mussels fall down from the surface buoys and become food for animals on the foundations and on the adjacent seabed. Lobsters also settle under the foundations. In a large-scale experiment, holes were drilled in the foundations, and this dramatically increased numbers of crabs. The position of the holes also proved to be of importance for the crabs.

Actively designing wind and wave farms to create great artificial reefs (instead of letting it happen by accident, leading to sub-optimal reefs) is a great opportunity to achieve two objectives at once. I think more research should be put into what makes a good, productive and healthy artificial reef, and that the anchoring foundations of wind and wave farms should be built to those specifications (while of course also meeting other engineering objectives of durability and such).

Via ScienceDaily

