Dangerous waters

Can we find a way to share the sea with those majestic giants of the deep, the North Atlantic right whale? The question is urgent. With only perhaps 500 of the endangered marine mammals left, a spate of right whale deaths in recent months has alarmed all concerned with saving these cetaceans. At least 13 right whales have died off the Atlantic seaboard this summer — 10 in the Gulf of St. Lawrence and three more in U.S. waters.

Necropsies so far point to ship strikes and fishing gear entanglements as responsible. Unfortunately, right whales’ natural behaviour puts them at risk in waters heavily used by humans.

The whales, which can live at least 75 years, stay close to coastlines, making contact with marine traffic and fishers more likely.

They feed at the surface, filtering tonnes of seawater for zooplankton.

That leads to entanglement with fishing gear. They’re slow swimmers and tend to ignore nearby ships, even if on a collision course.

That’s all been long known.

But despite those factors, the still-endangered population has grown from an estimated 300 individuals less than 20 years ago to today’s numbers.

So what’s changed?

As Halifax Chronicle Herald journalist Tom Ayers reported Wednesday, right whales are appearing in the Gulf of St. Lawrence in unprecedented numbers but scientists say a lot more research is needed to understand why.

That includes where the whales are going and when.

Since a moratorium on whaling was put in place in the 1930s, the U.S. and Canada have brought in various additional measures to protect the right whale.

In 2002, the International Maritime Organization OK’d shifting shipping lanes in the Bay of Fundy — where there’d been numerous right whale deaths due to ship strikes — after a request from Ottawa. The measure worked, cutting collisions by at least 80 per cent.

But the Gulf, where right whales have been increasing since 2011, is a “superhighway” of marine traffic and fishing efforts, as Dalhousie University biology professor Boris Worm put it.

Ottawa deserves credit for closing the snow crab fishery in that zone two days early in July and ordering larger vessels in the Gulf to slow down earlier this month.

But if climate change, which some researchers say has reduced the whales’ food supply in the Bay of Fundy, has changed their migratory patterns, much more needs to be done to protect them in the more dangerous Gulf.