2022 Alberta Fish Rescue

by | Jan 5, 2023 | News | 0 comments

2022 Alberta Fish Rescue
By Lili-Maude Craig, Fisheries Technician, and Evan Tichonuk, Fisheries Technician

In spring, while mindlessly swimming down the Oldman River in southern Alberta, you followed the flow of water through the unscreened headgates of a diversion on the river. This diversion conveys water into an 88 km long irrigation canal that supplies water throughout the Lethbridge Northern Irrigation District. You moved downstream through the gate of a check structure and unintentionally made a home of a deep pool below it. Since you were unable to make your way back upstream, you spent all summer here in the canal.

It is now October, an unseasonably warm October that has you oblivious to the changes soon to come. Canal operators are preparing to close the headgates of the canal to ensure they can conduct regular maintenance during the winter months and prevent damage to the structures from ice jams. When the headgates are shut, water is no longer being supplied to the canal, and water levels drop as the canal continues to drain. Seeps and precipitation will still provide the canal with water, though not enough to sustain those left stranded like you throughout the winter.

A few days go by, and you and several hundred other fish congregate in the deepest section you can find once the flow to the canal is finally cut off. You watch as others get picked off by gulls and larger fish, hoping neither becomes your fate. Lucky for you, a group of people with tubs, nets, and what you can only describe as “proton packs” from “Ghostbusters”, make their way down the banks and into the canal. They begin to wade towards you, and before you know it, you undergo “galvanotaxis” and are scooped out of the water by a swift netter, placed into a tub and transported out of the canal to be processed. You are then identified to species, counted on a tally sheet, and put into an oxygenated holding tank before being released back into the Oldman River.


Alberta Fish Rescue


You are a 52 mm Spoonhead Sculpin, one of 1,294 fish captured from “LNHC 2” on October 14th, 2022, during Trout Unlimited Canada’s annual Fish Rescue. A total of 21,365 fish were rescued across all sites at the Lethbridge Northern Headworks Canal; across all of the four irrigation canals sampled, 72,055 fish (except aquatic invasive species) were rescued and released back into their source rivers. For comparison, that is almost as many fish as caught in 21 years of Fish Rescue at the Western Headworks Canal (74,804) and nearly 20,000 more fish than what has ever been captured in 17 years of rescue efforts at the Waterton-Belly Diversion Canal (55,231). A total of 1,079,668 fish have been captured from 1998 to this date.


Crunching the Numbers

Species WHC CBRHC LNHC WBD Total Percentage of total (%)
Sportfish BLTR 0 0 4 0 4 0.0%
BNTR 27 928 1,025 17 1,997 2.8%
BURB 0 4 2 79 85 0.1%
LKTR 0 0 0 1 1 0.0%
LKWH 1 0 2 678 681 0.9%
MNWH 3,276 2,585 4,584 32 10,477 14.5%
NRPK 0 0 26 13 39 0.1%
RNTR 1 1,280 565 3 1,849 2.6%
YLPR 80 12 0 0 92 0.1%
Total Sport Fish 3,385 4,809 6,208 823 15,225 21.1%
% Sport Fish 8.3% 55.1% 29.1% 63.7%
Non-Sportfish BRST 62 23 7 0 92 0.1%
EMSH 0 0 7 0 7 0.0%
FTMN 40 75 8 1 124 0.2%
LKCH 442 10 373 8 833 1.2%
LNDC 782 2,168 884 106 3,940 5.5%
LNSC 2,582 978 3,167 221 6,948 9.6%
MNSC 23 19 14 3 59 0.1%
PRCR 3 4 0 0 7 0.0%
PRDC 3 0 0 0 3 0.0%
SPSC 377 0 438 31 846 1.2%
TRPR 3 21 13 74 111 0.2%
WHSC 1,855 623 10,246 26 12,750 17.7%
Total Non-Sportfish 6,172 3,921 15,157 470 25,720 35.7%
% Non-Sportfish 15.2% 44.9% 70.9% 36.3%
Unknown UNKN 31,110 0 0 0 31,110 43.2%
Total Unknown 31,110 0 0 0 31,110 43.2%
% Unknown 76% 0% 0% 0%
Total 40,667 8,730 21,365 1,293 72,055 100.0%



This year, sportfish made up 21.1% of the total Fish Rescue catch. The most abundant sportfish species encountered were Mountain Whitefish, Brown Trout, and Rainbow Trout, accounting for 14.5%, 2.8%, and 2.6% of the total catch, respectively. White Sucker and Longnose Sucker were the most abundant non-sportfish species, representing 17.7% and 9.6% of the total catch, respectively. Approximately 43.2% of fish rescued could not be identified. These unidentified fish were captured at the Western Headworks Canal, where there were significantly higher than anticipated volumes of fish. They needed to be transferred en masse, by hand, back to the Bow River due to time constraints. These fish were therefore recorded as “unknown” species.


Featured Fish

Records were broken this year when a 1,001 mm Lake Trout was caught at the Waterton-Belly Diversion Canal (WBD). This Lake Trout is the biggest fish ever recorded in Fish Rescue history. Other impressive catches from this year’s rescue efforts include a 750 mm Bull Trout (one of four captured at the Lethbridge Northern Headworks Canal), a 710 mm Northern Pike, and a 685 mm Burbot. A 346 mm Prussian Carp was caught at the Carseland-Bow River Headworks Canal, the largest of this species captured at a Fish Rescue to date. Let’s not forget the monster Trout-perch measuring 85 mm that was also caught at the WBD canal (unfortunately outshone by the Lake Trout).


Volunteer Abundance

Over ten days of fieldwork, 137 volunteers contributed 1093 hours of effort. Fish Rescue has been able to take place year after year, largely because of the help provided by dedicated volunteers. New volunteers, volunteers joining for multiple days of rescues, and volunteers who have participated in this project for numerous years all play a significant role in minimizing the impacts of fish entrainment in southern Alberta’s irrigation canals.

TUC is also grateful for the Alberta Agriculture and Irrigation (AAI) staff who assisted with the 2022 Fish Rescue. This includes support in the field with fish capture and processing, fish holding and release, and providing space to decontaminate gear to prevent the spread of whirling disease and other aquatic invasive species.

Thank you to all involved in making the 24th Annual Fish Rescue possible! We hope to see you again next year!


Alberta Fish Rescue

Photo Credit: David Bradford


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