Melting Arctic could cause mollusks to migrate

Mollusks from the Pacific could march into the Atlantic Ocean within decades because of the melting of Arctic sea ice, researchers in California say.

HALIFAX — Mollusks from the Pacific could march into the Atlantic Ocean within decades because of the melting of Arctic sea ice, researchers in California say.

For mollusks to pass, the Arctic would need to have less than 75 per cent sea-ice cover for 125 consecutive days — something that could happen around 2050, according to an estimate two years ago by the Intergovernmental Panel on Climate Change.

But Peter Roopnarine, curator of geology and paleontology at the California Academy of Sciences in San Francisco, says that could happen sooner.

“We could be looking at between 2020 and 2030,” says Roopnarine.

Roopnarine and Geerat Vermeij, a geologist and evolutionary biologist at the University of California, Davis, say Pacific-to-Atlantic migration is probable for all kinds of sea life, including fish, crabs, sea stars, sea urchins and seaweed.

They base much of their theory, which first appeared in the scientific journal Science last year, on fossil records from the last time mollusks traversed the Arctic: about 3.5 million years ago.

At the time there was a shift in climate, which kept the Bering Strait open long enough to allow hundreds of species, such as mollusks, cod and herring, to migrate from the Pacific to the Atlantic over the ice-free Arctic.

Some of the species became extinct, but others colonized the Atlantic and continue to populate its waters today.

Roopnarine says a similar phenomenon is in the offing.

“A lot of fish, for example, are certainly going to be part of this invasion,” he says.

“It’s going to change the entire composition of the Northwest Atlantic ecosystem.”

Roopnarine said this migration could bring new fisheries to Atlantic Canada.

He added that it’s possible some species would be able to make the journey in one summer, though most would move through the Arctic waters more gradually.

The entire journey, he predicts, would take “at most a few years.”

Depending on their size, mollusks may arrive in a number of ways, such as being carried by currents, crawling, and floating on seaweed or logs, Vermeij says.

He says most creatures would travel eastward because of currents and Pacific species tend to be larger, therefore more able to cross the Arctic Ocean.

Those that cross would likely stay in the Northwest Atlantic because waters east of that area are too warm, Vermeij says.

There is evidence that a modern-day inter-oceanic migration may have already begun.

In 1999, British oceanographer Chris Reid discovered a microscopic Pacific plant known as the Neodenticula Seminae diatom in the Atlantic Ocean which has since settled and spread throughout Northwest Atlantic waters.

Reid says the plant was in the North Atlantic until 800,000 years ago, when waters became too cold for it to survive.

Reid and other researchers from the Hardy Foundation for Ocean Science in England concluded that the plant travelled from the Pacific over Arctic waters into the North Atlantic.

In 1998, Arctic ice retreated to the north of Alaska and Canada for the first time on record, leaving open water all the way from between the Pacific to the North Atlantic, Reid says.

“So, it fits the story really well,” he says.

The only other plausible theory, says Reid, is that the diatom came from a ship’s ballast water. But he doesn’t think that’s likely because ships do not discharge their water in the middle of the ocean, where they found the plant.

Since it’s discovery, the plant has spread from the Labrador Sea down the East Coast. A large concentration was found in the Gulf of St. Lawrence in 2001.

Michel Starr, a scientist with the Department of Fisheries and Oceans, said the ecological impact of the plant on the North Atlantic coast has not yet been determined.

Starr says it is still present in the Gulf of St. Lawrence but there are less than there were in 2001. He said he doesn’t know why.

Starr believes more organisms will follow the plant’s route, which will carry implications on current life in the Atlantic Ocean.

“We can expect a reorganization of the North Atlantic ecosystem,” says Starr.

While some invasive species, like the European green crab, have displaced native species along both coasts of Canada, Vermeij is not worried about the mollusks having the same effect.

“They’re not going to eliminate the Atlantic species,” he said.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Lieutenant Commander Nicole Robichaud welcomes members of the Liberian Coast Guard aboard the HMCS Moncton for training with Royal Canadian Navy off the coast of Monrovia, Liberia, Africa. (Contributed photo by Corp. Ryan Moulton)
Red Deer-raised woman finds her sea legs as commander in the Royal Canadian Navy

Cdr. Nicole Robichaud started out as a local sea cadet

Rode
Feddema adds size and grit to RDC basketball Queens

Iris Feddema has known for several years what she wanted her future… Continue reading

A local photographer captured the contrails of two planes that crossed in the sky over north Red Deer on Wednesday. (Photo contributed by Eric Fischer)
Photo: Planes criss-cross over Red Deer

A local photographer captured the contrails of two planes that crossed in… Continue reading

Red Deer Public Schools will not pilot the new draft curriculum at its elementary schools. (File photo contributed by Red Deer Public Schools)
UPDATED: Red Deer Public Schools says no to piloting new curriculum

Alberta Teachers’ Association support school boards

A man injects hydromorphone at the Providence Health Care Crosstown Clinic in the Downtown Eastside of Vancouver, B.C., on Wednesday April 6, 2016. THE CANADIAN PRESS/Darryl Dyck
NDP lawmaker tables bill to decriminalize drug use as overdose deaths soar

NDP lawmaker tables bill to decriminalize drug use as overdose deaths soar

Conservative leader Erin O'Toole holds a press conference on Parliament Hill in Ottawa on Tuesday, April 6, 2020. THE CANADIAN PRESS/Sean Kilpatrick
Low-carbon bucks: Conservatives pitch consumer carbon pricing through savings account

Low-carbon bucks: Conservatives pitch consumer carbon pricing through savings account

Deputy Chief Public Health Officer Howard Njoo responds to a question about vaccines during a weekly news conference, Thursday, Jan. 14, 2021 in Ottawa. Njoo says a faster vaccine ramp-up alone would likely not have thwarted the third wave of COVID-19 in many parts of the country. THE CANADIAN PRESS/Adrian Wyld
Ottawa’s COVID-19 vaccine point man aims to ensure more predictability for shipments

Ottawa’s COVID-19 vaccine point man aims to ensure more predictability for shipments

Evan Siddall is pictured in Ottawa on September 21, 2017. Former head of Canada Mortgage and Housing Corp. Evan Siddall has been named as the next chief executive for Alberta Investment Management Corp. He will succeed Kevin Uebelein. THE CANADIAN PRESS/Sean Kilpatrick
AIMCo names former CMHC head Evan Siddall as next chief executive

AIMCo names former CMHC head Evan Siddall as next chief executive

A for sale sign is shown in by new homes in Beckwith, Ont., just outside Ottawa, on Wednesday, Jan. 11, 2018. THE CANADIAN PRESS/Sean Kilpatrick
Canadian home sales up 76% year-over-year, set new March record: CREA

Canadian home sales up 76% year-over-year, set new March record: CREA

WestJet president and CEO Ed Sims addresses the airline's annual meeting in Calgary, Tuesday, May 7, 2019. THE CANADIAN PRESS/Jeff McIntosh
WestJet CEO Ed Sims finds Air Canada aid package ‘bittersweet’ as talks drag on

WestJet CEO Ed Sims finds Air Canada aid package ‘bittersweet’ as talks drag on

The TMX broadcast centre is shown in Toronto on May 9, 2014. THE CANADIAN PRESS/Darren Calabrese
S&P/TSX composite, Dow Jones and S&P 500 set record highs as mood rises on economy

S&P/TSX composite, Dow Jones and S&P 500 set record highs as mood rises on economy

A man wearing a protective face mask to help prevent the spread of COVID-19 checks his phone as the sun sets in English Bay in Vancouver on April 5, 2021. Canada's existing mobile phone services and consumer groups will get a landmark ruling from the CRTC this afternoon. The regulatory ruling could shift some of the market power held by Rogers, Bell and Telus, which collectively have more than 90 per cent of the country's subscribers. THE CANADIAN PRESS/Jonathan Hayward
CRTC to allow smaller wireless players better access to national networks

CRTC to allow smaller wireless players better access to national networks

Most Read