Sproat Lake users and residents are becoming more aware of the invasive species that were intentionally introduced to the lake and now call it home.
The Invasive Species Council of British Columbia has confirmed that sunfish, koi and bullfrogs have been reported in Sproat Lake in the last couple years, and the number of sightings is on the rise.
ISCBC executive director Gail Wallin said the council believes these species have been introduced to the lake intentionally. "The American bullfrog is a huge frog," Wallin said. "As soon as you introduce a big, aggressive frog, it will have the ability to offset the ecosystem by displacing the native species. Most invasives like this are intentionally introduced."
Several years ago, Sproat Lake resident Gary Rutter tried to tackle the koi, also known as the common carp or goldfish, problem with some other lake residents, but they were unsuccessful.
They tried to corral the fish in a seine, but they all jumped out. They also tried to capture them with a gill-net, but it proved ineffective for the same reason.
Last year, Rutter said his dock near his Wiener Bay home was surrounded by koi. This year, he hasn't seen a single carp.
"They are still here and they're around. They are just getting bigger and they're changing their habits," Rutter said.
Koi increase water turbidity, reducing the abundance of aquatic plans and even rendering water unsuitable for drinking and swimming.
Also on the list of B.C.'s most unwanted invasive organisms, is the American bullfrog. Wallin said the large frogs are being reported more frequently.
They are voracious predators known to eat rodents, small turtles, snakes, crayfish, frogs, birds and many invertebrates.
While the sunfish is the least reported species of the three, it has also been confirmed that they inhabit the lake.
Wallin said the problem with the invasive species is getting rid of them once they have been established in their new surroundings. With certain species, including sunfish and koi, eradicating them would result in killing off the native species. However, the bullfrogs are a little easier to eradicate. Wallin said there is a group of professionals trapping bullfrogs on a lake in the Okanagan. ISCBC will meet with those involved to see if it was successful.
Boat owners are urged to clean their boats before moving them to other lakes to avoid spreading invaders. To report invasive species, call 1-888-933-3722.
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