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Salmon returned to Cape Breton Highlands home

JESSICA SMITH ENVIRONMENT REPORTER jessica.smith@cbpost.com @Cbpost_jessica

INGONISH — Sarah Penney felt like a proud parent earlier this month as she watched a group of young adult salmon splash back into their native environment.

“It never gets old,” said the Parks Canada resource management officer. “I could do it all day, every day.”

Penney was part of a group that released 18 young adult salmon back into Clyburn Brook in the Cape Breton Highlands on Oct. 6. The fish were captured as young parr from the brook in 2019 and were reared at Dalhousie University's Aquatron Laboratory in Halifax, part of a Parks Canada effort to nurture declining salmon populations back to self-sustaining rates.

“It's really wonderful to see a creature that we captured a couple of years ago as a tiny little 15 or 20 gram fish come back to the river a couple of pounds heavier and looking healthy,” said Penney. “Getting hands-on with conservation and helping the ecosystem is really, it's really special. I'm really grateful to do this job.”

THE FIRST RELEASE

The program began in 2019 and is also a partnership with four other national parks and local First Nations in addition to the Aquatron. The last run of young salmon were picked up from Clyburn Brook in June of this year, to be studied, reared at the Aquatron and eventually released back into their habitat.

The Oct. 6 salmon release was the first of three scheduled so far for this program, which runs until 2024 but could be ongoing depending on funding.

“The release went really well. We had an excellent day weather-wise, which was a real bonus,” said Penney. “We had 18 fish that the Aquatron drove down from Halifax and delivered to the river, and we had just a small group of key partners and stakeholders attend the release to put the fish back in the river.”

Penney said the fish were shipped from Halifax in large blue plastic tanks injected with oxygen to keep the fish

comfortable. Once they arrived at Clyburn Brook, some of the river water was then added to the tanks to slowly acclimate them to differences in water.

The group, which was limited in numbers due to COVID-19 restrictions, then scooped each fish up, one by one, in nets and passed them, assembly-line style, down a chain into the river.

“And that was like a 10 to 15 second trip, pretty quick. And then, we would dip the net into the river as soon as we were close enough and then help guide the fish out of the net and on its way up the river,” said Penney.

Shelley Denny, director of aquatic research and stewardship with the Unama'ki Institute of Natural Resources, attended the Oct. 6 release.

“I think it was really neat, it was well co-ordinated and well planned,” said Denny of the release. “And it was a different kind of opportunity to have salmon that were pretty much reared in captivity, released after their smolt stage (and) pre-spawning.”

Denny said she brought some waders with her and took part in the actual releasing of the fish back into the river.

“These are big fish coming in, right, so it wasn't like you're releasing a little tiny salmon,” said Denny. “... It was quite the experience of, you know, getting in the water. I felt honoured being splashed by the salmon, so that was pretty cool.”

MONITORING SUCCESS

Penney and the other Parks Canada scientists then returned to the river on Oct. 7 and completed a swim through to check on the fish.

“We did see some fish still holding up in the pool where we had released them and a couple had moved upstream. So they're settling in nicely,” said Penney.

The release date was, by design, a month before the typical spawning time for salmon, which take cues from their environment to decide when to start.

“So putting them back in the river with a bit of delay, before it's time to mate, allows them to take in those signals and get their bodies ready ... their circadian rhythms, you can almost call it, that can sync with the rest of the wild fish."

In a couple of weeks, Penney and her group of scientists will do a snorkel survey of the river and return annually to count the adults who return to the river to spawn. Each fish reared in the program is equipped with a tag that has a unique code on it, so that they can distinguish those reared in captivity at the Aquatron from wildreared salmon.

“We'll be able to see sort of who's who, which fish were involved in our program and which fish weren't,” said Penney. “And then going forward, once they've had a chance to spawn and their eggs hatch and the juveniles grow up a little bit, we'll be doing some genetic analysis ... on the baby fish in future years to see who their parents were.”

This, though years down the line, will help them determine the success rate of the program in helping sustain wild salmon populations, said Penney. There are two more releases planned so far, with the first scheduled a year from now in October 2022.

Denny said she's interested to see the long-term results from the study, especially those that compare the salmon raised in captivity with those reared in the wild.

“What happens to them when they're not fed ... by hand or by a mechanical device? How do they fare out in the wild?

“So I'm really interested in seeing like ... are they able to spawn? Do they leave the river and then will they return again? So that's kind of ... what my interest is in.”

OPINION

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2021-10-26T07:00:00.0000000Z

2021-10-26T07:00:00.0000000Z

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