A voracious predator new to the East Kootenay has resulted in the closure of two local lakes to sportfishing.
New Lake, near Cranbrook, and Fussee Lake, east of the Koocanusa Reservoir have been closed to sport fishing until further, notice due to the illegal introduction of invasive fish species, including large-mouthed bass (Fussee Lake) and yellow perch (New Lake).
These invasive species can severely impact other aquatic species, including native minnows, young trout and salmon, as well as amphibians and invertebrates, and are a considered a major threat to British Columbia’s freshwater fisheries through effects of competition, predation, parasites and disease.
“Not only will they compete directly with the native fish populations, they also compete for food sources, and do a pretty good job. They are very good predators,” said Heather Lamson, a biologist with the Mininstry of Forests, Lands and Natural Resource Operations.
“For instance, largemouth bass are very predatory — they eat other fish for their main diet. If they are introduced to local waterbodies, they tend to eat anything they can get their mouths around. Basically any fish they can fit in their mouths they will predate on. Fish, amphibians, invertebrates …”
“[The invasive fish species] have been illegally introduced into waterbodies all over the place in this region,” Lamson said. “There are heavy fines involved for that if people are caught. But also, those waterbodies are closed to fishing for a period of time.”
Lamson added that once those introductions have occurred, and those populations have been established, it is very hard to get rid of the fish.
“There are methods, but they’re very costly — a pesticide, for instance, that have been used in other places in the province, but it costs about $100,000 to apply.”
The lake closures serve two purposes: They are partly a disincentive for any anglers who are trying to create a bass or perch population to fish.
“If they know we’re going to close a lake, hopefully they won’t move a fish into that lake — maybe people don’t actually know this is illegal when they go to create these waterbodies with fish that they’re used to and like to catch.
And Conservation Officers will fine people who fish in these waterbodies.”
Secondly, the closures will prevent other transfers from those waterbodies. The lake is basically put under quarantine, reducing contact.
A press release from FLNRO said the most effective way to protect British Columbia’s lakes and rivers from this threat is prevention. Live fish should not be moved or released into any of B.C.’s waterbodies. Any fish of concern should be reported to the ministry’s regional fish and wildlife office.
Fussee Lake and New Lake will remain closed to fishing and will not be stocked with trout until the large-mouthed bass and yellow perch populations have been eradicated.
“We’re not saying those lakes will be closed forever,” Lamson said. “Just for a period of time, and then they’ll be reopened under certain regulations.