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Reservoir Walleye Spawning Enhancements
by Jeff Bronsch

 

This past February of 2001 the ACA (Alberta Conservation Association) took advantage of the low reservoir waters levels in southern Alberta by enhancing the walleye-spawning habitat on three reservoirs. Approximately 2300 tonnes of spawning substrate consisting of coarse gravel and cobble was placed in Chin, Ridge and St Mary reservoirs over the winter. “With water levels being below average we thought it would be a great opportunity to build some spawning beds over the winter” says Trevor Council from the ACA. The beds were built on the windward shoreline to take advantage of the wave action which is needed to keep fertilized eggs free from silt during the spawning period. The spawning beds were also built at an elevation so they could be utilized by varying water levels from year to year.This project was the combined effort of the ACA, Alberta Environment and the Lethbridge Fish and Game Association. As well, letters of support came from Walleye Unlimited and GoWalleye.com. Alberta Environment fisheries biologists Terry Clayton and Glen Clements provided technical expertise for the project. Alberta Environment’s operations support branch provided equipment and manpower for hauling and spreading the material at the project sites. The province runs St Mary and Ridge reservoir, but Chin reservoir is part of the St Mary River Irrigation District. “The St Mary River Irrigation District was supportive in letting this project take place last winter on one of their internal storage reservoirs” says Trevor Council.

There are plans to try and measure the impact these new spawning areas will have on each reservoir when water levels return to normal. Beach seines will identify young of the year adjacent to the new spawning areas, underwater cameras and physically looking for eggs on the spawning beds.

“We are very optimistic that successful spawning will happen on the new spawning beds and we’re expecting the new beds will last ten years before they are eroded or silted over by wave action” says Terry Clayton, fisheries biologist. If the outcome of these new beds is as positive as Alberta Environment hopes, there are plans to do more of this type of work.

For the most part spawning habitat is hard to come by on many of the southern Alberta reservoirs. Riprap dams and other rocky areas are places walleye seek out for spawning. With the current low water levels on many reservoirs it is easy to see how barren these water bodies are from rock and good spawning habitat. These new rocky areas will most likely hold baitfish drawing the walleye back to these same areas for different reasons. As anglers know any underwater structure or feature may hold fish so these newly created areas have a good potential holding a certain amount of the fish population all year long.

The walleye have become a very popular sportfish with Alberta anglers so any improvement to fish habitat and the potential for increasing fish populations is a welcome sight by anglers. Natural fish reproduction or recruitment is something fisheries biologists would like to see more of as well. Any improvement to this natural recruitment would be welcome as Alberta Environment’s current walleye management strategy does not support walleye stocking. 

Walleye Spawning Facts:
Walleye spawning in southern Alberta happens in early May.
It takes about 5 years for a walleye to reach maturity before it will spawn.
One 5lb fish can produce 160 thousand eggs.
Less than 1 in 100 will survive to become an adult fish.
Southern Alberta has a spring fishing closure to protect fish species that spawn in the spring.