With the ice deteriorating and the ice shacks removed, recreational fishing is closed until May 14. As anglers prepare for the coming spring and summer fishing season, Alberta Environment and Parks and the Fish and Wildlife Policy Branch took stock of the lake and made decisions on size limits.
Senior Fisheries Biologist, Jason Cooper, and Fisheries Scientist, Michael Sullivan provided some background on the fisheries management objectives for Sylvan Lake for this year.
According to a report used for a consultation process last year, the current concern for Sylvan Lake is the overharvest of Walleye and Northern Pike.
A Fish Sustainable Index Adult Density Score is given to each fish species to decide whether it has a low risk, moderate, high or very high risk to sustainability.
To monitor the status of fish in the lake,scientists set gill-nets. The catch rate or fish per net reveals whether abundance is high or low. The catch in 2017 for pike was less than one adult per net which, compared to a “good catch rate” of more than 10, which means the pike are considered a very high risk to sustainability.
“Our monitoring also showed that few young pike are present (another bad sign),” wrote Sullivan in an email.
After surveying anglers across Alberta to ask about objectives for specific lakes, Sullivan found that most Sylvan Lake anglers were more interested in a “fishery that provided some harvest as opposed to a trophy fishery.”
“The trade-off for allowing harvest is that fewer fish get to very large size, so…you can’t have your cake and eat it too. The choice is harvest or trophy. Anglers at Sylvan chose the harvest objective.”
According to Sullivan, the issue of size limits and protecting breeding fish is complex and Alberta’s regulations allowing the harvest of big fish certainly seems wrong at first glance.
Sullivan gave this example to explain:
“A big 100 cm pike might have 100,000 eggs, and a smaller 60 cm pike may only have 25,000 eggs. If you were managing your live-well in your boat and have caught one big female and one smaller female,you would certainly save more eggs by releasing the big one. Makes perfect sense for your personal catch ratio of one big and one small fish.
Now, however, imagine you are managing not just your personal catch, but you are a biologist managing the entire lake’s fishery. That catch ratio is not one big fish to one small fish. At Alberta lakes, biologists analyze the catch of hundreds and thousands of anglers.
For every big female fish caught by anglers, there are typically 20 smaller females caught. For pike, that one big fish might have 100,000 eggs, but the 20 small fish would have, in total, 20 x 25,000 eggs or half a million eggs.
Releasing the numerous small breeders and harvesting the one older fish puts many more eggs back into the lake (typically five times more eggs at most Alberta lakes). If anglers want to harvest a fish, it makes sense to keep the harvest of eggs low, and that means releasing the numerous small spawning-sized fish.”
“As you see, there is quite a difference between managing your catch and managing the entire lake.”
So how does the size limit or regulations tie into the reality of a fish population and the desired outcome? For Sylvan Lake it means temporary harvest restrictions, which translates to catch-and-release for a few years for the fish species at high risk
“When Sylvan recovers (e.g., when the density rises from one fish to at least 10 fish per net) we will implement a different regulation, either a size limit or a tag system, depending on the fishing pressure,” wrote Sullivan.
Alberta’s biologists are responsible for ensuring fish populations are allowed to flourish and provide benefits for future fishermen. They use modern scientific knowledge and are highly trained in the complexities of fisheries management.
At most lakes, there are far more small fish than big fish. Typically in Alberta, 20 anglers will each catch a small spawning-sized pike, and only one angler will catch a big pike.
Regulations’ requiring those 20 small spawners to be released saves many more eggs than releasing the one big fish. In the past 20 years, Alberta’s size limits on pike and walleye have changed fisheries from collapsed to healthier and more sustainable fisheries. However, there are some fisheries where further changes are required to address concerns, such as the case for Sylvan Lake.
“The catch-and-release regulation at Sylvan Lake is not to promote “trophy” fishing. It is to reduce the kill of fish until the population recovers,” wrote Sullivan.
What this means is anglers are asked not to do anything that would cause harm to the fish including holding the fish out of water, fishing in deep water or use techniques like certain hooks that can contribute to a damaged fish.
Sullivan encourages anglers to become better and more ethical fishers:
“There are lots and lots of great websites, articles and information out there on good fish release practices. Read up, learn what might work best for the way you fish.”
-with Michael Sullivan and Jason Cooper