British Columbia

Goldfish invasion closes popular lake to fishing in northwestern B.C.

Biologists say the closure is necessary to assess the extent of the problem and come up with a plan to prevent the invasive species from spreading to the Skeena watershed.

Biologists say the invasive species has been observed in different sizes which means they are reproducing

The species is native to eastern Asia and is known to compete with, and prey upon, native fish. (Windsor Aguirre bugwood.org/Ministry of Forests, Lands, Natural Resource Operations)

You may think of them as low maintenance pets that require nothing more than a daily sprinkle of food flakes.

But the type of goldfish that have been discovered in popular Lost Lake near Terrace, B.C., demand attention, which is why the province has taken the unprecedented step of closing the lake to fishing starting on Saturday. 

The invasive goldfish — also known as Carassius auratus — have been detected in all sizes in the lake which suggests they are reproducing.

An alert posted by the Ministry of Forests, Land and Natural Resources says biologists are assessing the extent of the invasion to come up with interventions and treatment options to prevent the goldfish from spreading into the Skeena watershed.

The species is native to Eastern Asia and is known to compete with — and prey upon — native fish. They can range in colour from gold to olive green to white and grow to be 15 to 20 centimetres long.

Although there have been sporadic reports of goldfish in the Skeena region's rivers and lakes, this is the first confirmed sighting. 

The ministry said the closure is warranted because of the lake's close proximity to Terrace and significant native fish populations.

Lost Lake is a kilometre away from the Kitsumkalum River, which feeds directly into the Skeena River, 10 kilometres to the south at Terrace.

It's not known how the goldfish ended up in the lake. According to the ministry, goldfish have been intentionally released into B.C. waters by pet owners and have been known to escape from outdoor ponds and aquariums.

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