July 17, 2013 — For decades, fishery management has focused almost exclusively on the need to restrict fishing. Now, environmental changes are forcing fishermen and regulators to reevaluate their traditional practices.
Ernie Eldredge has been fishing all his life – clamming, long-lining cod, and crewing on sea scallop boats. But weir fishing is his love and mainstay. Last May, Eldredge netted something (or rather, two somethings) that even he’d rarely seen before – an Atlantic croaker and a grey triggerfish.
Weir fishing on Cape Cod is a tradition that dates back hundreds, if not thousands, of years. The circular nets anchored by hickory poles are like underwater corrals that trap fish as they migrate along the coast. Eldredge still uses some of the gear his father did, and others before him. The chain stretches all the way back to the Native American inhabitants of Cape Cod.
Looking out over one of his weirs just off the beach in Chatham, Eldredge says he’s witnessed a major shift in recent years. The odd southern fish is part of it. The bigger problem, though, is that Eldredge’s traditional targets have moved offshore out of reach of his nets. This weir is empty, and he’s already disassembling his others two months earlier than usual. He blames climate change.
Rising carbon dioxide levels have profound consequences for ocean ecosystems. Water temperatures increase, ocean chemistry changes, and weather patterns shift. The microscopic plants and animals at the base of the food chain respond and the impacts reverberate through the ecosystem. The location, growth, reproduction, even behavior of fish is affected.
Coping with climate change will take an equally herculean shift in fishery science and management. Many experts say the key to weathering climate change is something called ecosystem-based management. As the name implies, the idea is to base any one decision on a comprehensive understanding of the entire ecosystem. It’s a logical idea but far from simple.
The first step is getting a handle on the physical and chemical changes taking place in the ocean. Dr. Jon Hare and his colleagues at the Northeast Fisheries Science Center have documented deviations in temperature, salinity, acidity, and nutrient levels in New England’s waters. They’re also seeing shifts in wind patterns and ocean currents in the Gulf of Maine. And that translates into ecological changes.
Read the full story and listen to the audio from NPR affiliate WCAI