High-voltage electricity surging through undersea power cables doesn’t bother local sea life, three new studies suggest. The work eases concerns that planned offshore power production from wind turbines and tidal generators would disrupt marine communities.
Tracking the movements of fish and crabs around underwater power cables, the new studies reveal that marine critters don’t shy away from the magnetic fields put off by the cables. One study even found that the thick cables can serve as artificial habitats and host undersea communities.
“There’s much less of a concern now,” said Ann Bull, a marine biologist at the Bureau of Ocean Energy Management in Camarillo, Calif., who presented two of the studies February 26 at the American Geophysical Union’s Ocean Sciences Meeting.
In the 1980s, the earliest underwater telecommunications cables clashed with marine lifestyle: Sharks intrigued by electrical fields defer by the cables would gnaw on the wires, leaving teeth behind often. Wrapping the cables in insulating material blocked the electric fields and stemmed shark attacks, but magnetic fields made by the cables remained. Laboratory experiments show that lots of marine creatures can feel possibly relatively weak magnetism, sparking fears that the wires serve as “electric power fences” that disrupt ocean life.
Commercial fishers particularly concerned that crabs wouldn’t cross undersea wires to discover bait in crab traps. To check this, Bull and her co-workers developed cages with two baited traps, among which needed crabs to complete over a dynamic power collection. Both Dungeness crabs (Metacarcinus magister) and rock crabs (Romaleon antennarium) had no issue crossing the range: In a huge selection of trials, the crabs chose each trap around half enough time.