A Risso’s dolphin died on the ocean beach at Georgica early Sunday. Though a professional necropsy determined its cause of death as a parasite, there will be some who say that offshore wind-power installation is to blame, though there is no evidence of that. But what is actually killing marine mammals remains difficult to sort out.
Whales in particular have been dying along the United States coast in larger numbers for going on a decade. In the Atlantic, humpback whales and right whales have been found dead with increasing frequency. Direct human action, such as ship strikes or becoming entangled in ropes or nets, is responsible in about 40 percent of the whales examined. For the critically endangered right whale of the North Atlantic, the toll has claimed more than one in five of its remaining population. Human interaction is seen as the right whales’ leading cause of death. Wind power site mapping and construction are thought not to be a factor.
Conservationists say that large-scale shifts in whales’ food sources must be considered. Schools of prey fish, like menhaden here, have multiplied along the coast, drawing the whales closer to shore and into a danger zone. Federal and state authorities have put ship speed limits in place to help. And some, like the Risso’s dolphin discovered over the weekend, may be dying of natural causes.
At its root, the stressed global environment has to be addressed — for whales and everything else on Earth. Anyone who is sympathetic to the plight of the oceans should consider buying only seafood harvested in a way that reduces environmental harm. The Sustainable Seafood Coalition’s ratings, though not perfect, are a good place to start. United States-regulated marine fisheries are superior to those of many other food-exporting nations; knowing where your meal comes from is important.
In the big picture, supporting cleaner energy production will help the oceans and what lives in them. Climate shifts are causing rapid and undesirable changes in the marine environment, including making seawater more acidic, which could imperil many types of shellfish. And fossil fuel extraction poses the risk of toxic spills.
Studies continue to determine to what extent offshore wind turbines are part of the problem. In the meantime, it is important to take on the enemies of the whales that we already know.