Editor’s note: This is the first in a series of articles submitted by the Lake Windermere Ambassadors about the fish that live in Lake Windermere.
Did you know there are approximately 16 species of fish living in our lake? Some of our fish are native to these waters and others have been introduced by humans and compete with native species for habitat and food. One of the native residents — the northern pikeminnow (Ptychocheilus oregonensis) — is known by some of you as “squawfish”, which is the name they were officially called until 1999. The name “northern pikeminnow” suggests the fish is a minnow of a northern pike. However, the new name given to them by the American Fisheries Society was chosen because this member of the minnow family resembles a northern pike. They are indigenous to B.C. and are the largest native minnow species we have.
How big do they get? Northern pikeminnow can reach over 60 centimetres long and weigh up to 13 pounds. Their average size in Lake Windermere ranges between 30 and 50 cm and they weigh between two to four pounds.
What do they look like? They have a dark green or green-brown back and a white/cream abdomen. Their head is relatively long — approximately 22 to 23 per cent of their total length. The eyes of adults are small and their tail is distinctly forked. The fins are clear, but the male’s fins distinctly change colour to yellow/orange during spawning periods. Mature individuals generally have a rounded belly.
Where and when do they reproduce? Spawning periods of northern pikeminnow occur once temperatures get above 12 degrees Celsius, usually between May and July. They generally spawn in shallow gravel beds along the lakeshore or riverbank. The fish tend to gather in large numbers and each female will spawn with more than one male. The females release their eggs near the river or lake bottom, where they will then settle in the gravel. The eggs hatch in a week. Sexual maturation is reached when these fish are about six years old and a foot long. Life doesn’t end after rearing their first young — they can live up to 30 years!
What do they eat? Northern pikeminnow are generally scavengers and their diet varies from insects to small fish. Young individuals (2 to 10 cm) will feed on insects until they grow bigger. Fish that are in the middle-size range will feed on plankton and small fish such as salmonoid fries and shiners. They are known as major predators in lakes because of their habit of eating other fish.
Are they good neighbours? One problem attributed to northern pikeminnow is that they can successfully dominate the streams and lakes in a watershed by filling a niche previously held by salmonids. When they are able to out-compete other native fish, they can become the dominant species in certain areas.
Would I want to fish for northern pikeminnow? These fish are fun to catch. They can be caught year-round in Lake Windermere. There is no daily limit. It’s up to you whether you want to eat them or not. They are edible, but many people consider their taste unpleasant. Local practice on Lake Windermere has been to either throw them back or sacrifice them as easy prey for osprey and eagles.
[Quiz: If you can list 10 of the species in our lake, your name will go in a draw for a free interpretive tour of the lake! Submit your list to firstname.lastname@example.org]
For more information, contact the Ambassadors at 250-341-6898, email@example.com or visit our office in the south annex of the Service BC building.
—Submitted by Danny Osborne and Kirsten Harma