03/23/2015 01:30 EDT | Updated 05/23/2015 05:59 EDT

Cod stocks off Newfoundland improving but recovery still years away: researchers

ST. JOHN'S, N.L. - Scientists tracking northern cod stocks off Newfoundland say there are hopeful signs of recovery but that any lifting of an almost 23-year-old commercial fishing moratorium is likely a decade away.

"In the past half a dozen years or so, we've seen a remarkable change," said George Rose, director of the Centre for Fisheries Ecosystems Research at Memorial University's Marine Institute in St. John's.

There are more fish, they're larger and older, he said.

"The fish are in much better condition and now we are sort of poised ... for the next big step which should occur in rebuilding an animal population."

It's called a "pulse of recruitment" which essentially means a spike in births.

Rose has studied the fishery for more than 30 years and is quick to put such progress in context.

Recent surveys suggest northern cod numbers of around 100,000 to 200,000 tonnes of biomass, he said.

"Historically, we were in the millions of tonnes."

A minimum spawning biomass of about 650,000 tonnes is what federal fisheries researchers have discussed to sustain any extensive commercial fishery, Rose said.

The northern cod moratorium, which threw thousands of people out of work after it was announced July 2, 1992, was initially to last two years. Rose was among those scientists who predicted at the time it would take much longer for stocks to rebound from a complex blend of overfishing, mismanagement and environmental factors.

They were right.

"I prefer to look at the whole ecosystem and not just one species," Rose said. "We're probably a decade or so ... away from anything that would be a recovery."

Warming water trends could ultimately help cod and caplin, a vital food source on which cod depend and which also collapsed in the 1980s, he added.

"As the caplin go, the cod will go."

The role of growing seal populations is another hotly debated topic around fish stock recovery off the northeast coast of Newfoundland.

"Harp seals have been increasing tremendously over the last couple of decades," said Jeffrey Hutchings, a biologist at Dalhousie University in Halifax.

"There is an imbalance, if you will, between predator and prey and it would not be surprising if the seals were having some impact on the recovery of cod. But the data really are not very clear in that regard."

What, if anything, should be done about seal populations is "a political decision," Hutchings said. But like Rose, he stressed that severely depleted fish stocks don't just bounce back even after overfishing stops.

Federal Fisheries Minister Gail Shea said Ottawa has worked to spur the recovery through dockside monitoring for groundfish landings, research investments and gear changes to limit any bycatch of cod.

She was not available for an interview. In an emailed statement, she said independent science supports a link between grey seals and the lack of cod recovery in the Southern Gulf of St. Lawrence.

When asked about a possible seal cull, Shea said it's "a complicated issue" that needs more input from researchers, governments and industry.

Still, Rose believes northern cod stocks are better poised for a recovery now than since the early '90s. Ottawa can help by ensuring the best possible research guides management decisions, he said.

"There's no recipe here. That's basically our job, is to try to nurse this thing back to health."

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