A biologist at Calgary's annual fish rescue says they've saved over 2,000 fish per year at the Western Irrigation District headworks canal.

Lesley Peterson, a biologist with Trout Unlimited Canada in Calgary, says every year the organization works with the provincial government to rescue stranded fish in irrigation canals in southern Alberta.

According to their website, Trout Unlimited Canada is a registered Canadian not-for-profit organization whose mission is to conserve, protect, and restore Canada's freshwater ecosystems and cold water resources.

"In the fall when the canals are shut down and the water drains for a little, we come in with a bunch of volunteers and our staff and we rescue as many fish as we can," she said.

She says so far their team has rescued over 900,000 fish from canals since 1998.

"During the day, we use electrofishing to capture fish from the upper 200 metres of the canal … After processing, fish are held in an aerated tank until the end of the day when they are released back into the Bow River," Peterson said in a release.

Lesley Peterson, a biologist with Trout Unlimited Canada, says most irrigation canals in southern Alberta have no screen or exclusion mechanism to prevent fish from getting into the canals. (Monty Kruger/CBC)

Peterson says most irrigation canals in southern Alberta have no screen or exclusion mechanism to prevent fish from getting into the canals, and once they do they can't get back to their rivers without human intervention.

"They don't come in here on their own free will and they're not choosing to come into the canal," she said.

"Since we started doing this, actually a couple of canals have been screened and we definitely consider that a big success."

She says that during the nine-day event, Trout Unlimited Canada spends time in the field rescuing the fish, as well as collecting information and raising awareness of fish lost to irrigation canals.

The annual fish rescue event is made up of volunteers and workers from Trout Unlimited Canada. (Monty Kruger/CBC)

"Everything gets counted. We count all the minnows and suckers and trout … So part of the goal of the project is, we have an opportunity to handle a lot of fish and so we have can contribute the data to provincial fishery databases," said Peterson.

They also spend time on educating their hundreds of volunteers about Alberta fish, as well as provide them an opportunity to learn how to identify, measure and handle the fish.

"We know that we're not rescuing all the fish from the canal — we just can't do it. But part of the other goal is to educate people about the issue and to provide that opportunity for people to learn a little bit about Alberta's fish species," she said.