Endangered Atlantic whitefish rescued for second time in five months

Two dozen critically endangered Atlantic whitefish have been rescued for a second time in just five months, first from invasive predators and now from Canada's Department of Fisheries and Oceans.

Dalhousie University offers to take juveniles from DFO

You will only find Atlantic whitefish in the Petite Riviè​re watershed. The critically endangered species has all but disappeared. (Bob Semple/www.hww.ca)

Two dozen critically endangered Atlantic whitefish may have been rescued for a second time in just five months — first from invasive predators and now from Canada's Department of Fisheries and Oceans.

Dalhousie University geneticist Paul Bentzen says he was "surprised, shocked and dismayed" when CBC News revealed DFO planned to return the endangered Atlantic whitefish back into a watershed infested with invasive bass and pickerel.

So he did something about it.

He offered to take them off the DFO's hands and put them in the Aquatron, the university's aquatic research facility.

It's an offer he says the university supports and DFO accepted Friday.

"We have a world-class facility here," Bentzen told CBC News. "We have kept Atlantic whitefish in the past. I think this is a real win-win solution.

"We can save these fish. We can rear them and we can do research without harming them — the kind of research that needs to be done to in order to save the species."

The department issued a brief statement about the development. "DFO is open to exploring this option with Dalhousie University."

Why this happened

In May, DFO took every juvenile Atlantic whitefish it could find from the Petite Riviè​re watershed, near Bridgewater, N.S., and moved them for safekeeping to the federal fish hatchery at Coldbrook.

The Petite Riviè​re watershed is the only place left on the planet where the ancient relative of the Atlantic salmon survives.

But its three lakes are gradually being overrun by invasive small mouth bass and chain pickerel, likely introduced by anglers unaware of the potential harm.

Alain Vezina, DFO Maritimes science director, said the department has been unable to find a new home in the wild and has no choice but to put them back where they were found.

"We don't have a safe habitat for them to release them into," Vezina said.

One of Canada's most critically endangered species

That made no sense to Bentzen.

"It is hanging on by a thread, or maybe several threads, but the strongest thread we have is these 25 fish in captivity because we don't know what's going on in the wild right now, but it isn't good. So this is a very positive development for the species."

He says Dalhousie will grow the fish to maturity, opening the possibility of captive breeding from these individuals, while research continues including full genome sequencing of the Atlantic whitefish.

Atlantic whitefish recovery team member pans DFO

Bentzen was not the only one opposed to returning the juveniles,  which are now 15 centimetres in length, back into the Lunenburg County lake system.

Two of the three lakes contain invasive species. One of them, Hebb Lake, no longer has detectable levels of Atlantic whitefish.

"That's a ludicrous decision," said Andrew Breen of the Bluenose Coastal Action Foundation.

Breen and the foundation have been part of the Atlantic whitefish recovery team effort for several years.

"We've gone to a lot of work and effort to collect those fish. There's been a lot of time spent not just by our organization but also DFO, a lot of money spent. To put them back makes no sense."

"We've actually got a foothold at the moment and some opportunities to do something. To put them back in where is the protection of the species at risk, where is the science in that?"

But Breen welcomed news that Dalhousie had stepped in.

Why DFO is cautious

Vezina questions captive breeding without a suitable alternative location for whitefish raised in any future program.

"We don't have a safe habitat for them. So it's not much point in having a very big captive breeding program if you are going to put them back in an area where there are invasives.  And so far we don't have a safe space for their release," he said.

He also says its not clear what impact their domestication would have on their survival, even if a place could be found to put them.

"Captive rearing and augmentation and recovery is a very risky strategy at this stage especially for the remaining wild population, the status of which is unknown."

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About the Author

Paul Withers

Reporter

Paul Withers is an award-winning journalist whose career started in the 1970s as a cartoonist. He has been covering Nova Scotia politics for more than 20 years.