Seafood buyers are reporting high lobster mortality and poor quality, which a federal scientist says may be because lobsters are extra fragile this year in Canada's largest lobster region off southwestern Nova Scotia.

Fishermen are catching lobsters, bigger than ever, in "crazy, crazy numbers," says Joel German, plant manager of I. Deveau Fisheries in Barrington Passage, but this winter, more than the usual amount have soft shells.

"It's not the same lobster as it used to be, so we can't hold them as long," he said. 

Lobsters generally grow out of and then shed their shells once a year in a process called moulting. As the shells grow back, they're soft, making the lobster easier to hurt — and harder to store and ship.

A late moult means those shells had less time to harden before the province's southwestern fishing season started in late November.

More lobster dying

In previous years, German said he'd store lobster bought in December until mid-March with a two per cent mortality rate.

This year, he said he's seeing a minimum of five to 10 per cent dying before shipping, with more never hitting a dinner plate.

"It's to the point the dealers can't sustain the hits," German said.

"A lot of guys lost their shirts this year big time because of quality issues."

West Pubnico Harbour

Fishermen in southwestern Nova Scotia reported bumped lobster catches in warm, calm water when the season open late last fall. (CBC)

Stewart Lamont, managing director of Tangier Lobster Company on the Eastern Shore, buys southwestern Nova Scotia lobster this time of year to ship live to more than 20 countries. 

Up to half is too soft to ship alive, he said. 

"Generally speaking, we sell those lobsters at a loss ... That's been the industry challenge this winter," Lamont said. 

"Our customers expect a premium, hard-shell lobster."

Previously, only 10 to 20 per cent would have to be sent for processing, he said.

Late moult makes lobster soft

A federal Department of Fisheries and Oceans marine biologist said he's not surprised the industry is seeing more easily damaged and low quality lobsters — but that it may not be cause for panic.

"This was an unusual year, it was a late moult and I don't have any reason to suspect it's going to be another late moult this year," said Brad Hubley, lead scientist on Nova Scotia's lobster team.

So far, he said, it's looking like an environmental fluctuation instead of a long-term trend. In fact, this summer the southwest even could see an early moulting season, if the warm winter on shore is reflected on the ocean floor, he said.

Each June and and July, a team of scientists study lobster catches and shell softness after the time lobster typically moult in that area.

Commercial lobster fishing off southwest Nova Scotia is pulling in record numbers — and the highest in Canada, according to their most recent stock status update. But far fewer lobsters than usual showed signs of having lost their shells.

Percentage of southwestern NS soft shelled lobsters during DFO summer surveys

The percentage of southwestern NS soft shelled lobsters during DFO summer surveys has dropped in recent years, indicating a later moulting season. (CBC News Graphics)

Few moulted on time last summer

Last year's study found only 1.23 per cent had soft shells around the normal moulting time in southwestern waters. In 2012, at least 27 per cent had already moulted. 

"When a lobster's freshly moulted, it's like jelly," Hubley said.

"Often times after they've moulted, they're very hungry, so when they're a little bit soft, they do tend to trap very well."

Last year, spring was unseasonably cold, and likely mixed with changing ocean currents, Hubley said. The colder the water on the ocean floor, the longer it takes the lobster to shed its shell.

They haven't "connected all those dots together yet," he said, and DFO will be studying the shells again this summer.

"Will climate change affect lobsters in the long term? Probably," Hubley said.

"It'll affect everything, but is this a direct result of climate change? I'm a little bit skeptical of that."

Lobster 'running out of steam'

The lobster catches have proved challenging enough Nova Scotia's provincial government made mandatory a handling course to prevent lobster deaths. All buyers must take a course in order to be licensed in 2017. 

German said the new rule misses why more lobster are dying this season. 

"It's not that it's mishandled. It's handled with care," German said.

"It's just that it's out of protein, it's running out of steam."

Lamont said he has written to Nova Scotia Fisheries Minister Keith Colwell, saying the quality handling program is timely, but should be mandatory for fishers, processors and dealers, too.

"It's been a much more challenging business model this year than normal," Lamont said.

"There are all kinds of issues that are possible in a changing environment with climate that we need to apply lots of lobster science."