CBC NEWS - Nova Scotia

NS fish hatchery is confronted by death disease and climate change

Paul Withers

Nov 10, 2021
More frequent drought conditions, warmer water temperatures and low oxygen levels are taking a toll on Nova ScotIa's flagship fish hatchery, according to the province's director of inland fisheries.

The hatchery is the source of 650,000 cold water trout and salmon released annually into provincial watersheds for recreational angling.

A changing climate is stressing fish, resulting in a rise in disease, parasites and deaths at the hatchery in Frasers Mills, Antigonish County, according to the Department of Fisheries and Aquaculture.

'The effect of climate change'

"We are seeing more frequent, more prolonged low water and warm water periods," says Al McNeill, who directs inland fisheries. "We've had to add supplemental oxygen to provide oxygen during that warm water. Decades ago that wasn't an issue here.

"We have temperature records here going back to 1926. We've noticed the effect of climate change here. I think it's obvious. I see it first hand every day, not only here but in the wild."

The hatchery incubates four-million eggs per year.

It raises and releases 600,000 speckled, rainbow and brown trout at various life stages into rivers, lakes and streams. Another 50,000 Atlantic salmon are raised and released into their native rivers as fry and parr.

The hatchery uses 20,000 cubic metres of fresh water daily — enough to fill eight Olympic-sized swimming pools. Almost all of that comes from the South River, which runs alongside the hatchery.

During years with low rainfall in summer, the hatchery is unable to replenish its water reserve at South River Lake.

Last year was particularly bad.

Technicians removed beaver dams upriver to keep water flowing and staff worked around the clock for weeks filling up gas pumps for generators to recirculate water.

Looking for solutions

"We need to find a solution to this," said McNeill.

The province has hired aquaculture systems consultants Silk Stevens Design and Consulting Engineers to find a solution and the potential cost.

That investigation is ongoing but reusing the water supply is a likely answer.

"Many of the larger commercial hatcheries use recirculating systems," he said. "And, ultimately, that would certainly solve our problem here. So we've asked this company to provide us with some options."

The province's two other hatcheries are not in the same plight. McGowan Lake in Queens County draws from a deep water reservoir and the water supply into the Margaree, Cape Breton hatchery is colder.

Still, the challenges facing the facility in Frasers Mills are not unique.

McNeill said it is an issue across North America.

"We're all really addressing the same problem in different ways. It's certainly a challenge."

https://www.cbc.ca/news/canada/nova-scotia/nova-scotia-fish-hatchery-salmon-climate-change-1.6238668

More Posts