Whale-proof Fishing Gear

Current efforts to disentangle whales that become trapped in fishing gear, although essential, are "really only a Band-Aid," says a Duke marine-mammal expert who has participated in past whale rescues.

"It's something to do in the interim while we search for better solutions," says Andrew Read, the Rachel Carson Associate Professor of marine conservation biology at Duke's Nicholas School of the Environment and Earth Sciences. "What we're doing is kind of like emergency-room care for whales that become entangled. The real answer is developing fishing gear that doesn't entangle whales in the first place."

Read says large marine mammals usually become entangled in fixed lines extending from nets or lobster pots on the ocean bottom or floats or buoys on the surface. Ideas currently being tested to address the problem include weak links in the anchoring line that give way if a whale becomes ensnarled, or lines that decompose when exposed to the sun.

Read, who is based at Duke's Marine Lab in Beaufort, North Carolina, took part in a successful expedition several years ago to disentangle a humpback whale off Cape Lookout. "Humpback whales are easier to disentangle than right whales," he says. "Right whales are stronger and less amenable to work with. They can be very aggressive. They'll thrash their tails. People have had much less success disentangling them."

"And the stakes are much higher," he adds. There are about 350 right whales in the entire North Atlantic Ocean, and only a very few right whales in the Pacific. "So every loss is a significant one to the population. We think the population has been declining slowly for the last decade. A really good bumper crop of calves a couple of years ago helped. But the population is highly endangered and has a significant risk of extinction if we don't solve these problems."

Besides entanglement in fishing lines, right whales are subject to collisions with big vessels such as tankers, he says.