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The return of the kokanee salmon

By Veronica Sommerville,

Whistler Fish Stewardship Group

In 2001, the River of Golden Dreams at the bottom of Lorimer Road was inundated with kokanee salmon. The river was alive with sleek red bodies, diligently performing the dance of procreation. The young kokanee from last year will now be 2-4 inches long and feeding happily on plankton in middle layers of Green Lake. Plankton are tiny organisms that float freely throughout the water column. It will be another 3-4 years before we see the return of these particular fish.

The kokanee salmon have returned yet again to the River of Golden Dreams and Crabapple Creek. This is, however, a different run than last year. They were first spotted in the river on Sept. 2, about five days later than last year, and in much smaller numbers. They have moved quickly through the Lorimer section of River of Golden Dreams and can now be seen throughout Crabapple Creek along the Whistler Golf Course. The run will likely be finished by the end of the month, and the adults will die within three days to one week of spawning. It is normal to see major runs interspersed with minor runs for all types of salmon, whether they are land-locked or journey to the ocean. If everything goes accordingly, we should see another major run again in 2005.

In 1999, the Whistler Angling Club lobbied to have the fishing regulations changed in Alta and Green Lakes, from a four fish daily catch quota to catch and release only. Some local anglers are convinced this change in regulation is the reason for the healthy returns we have been seeing in the past couple of years. If you are skilled enough to catch a kokanee salmon, they are wonderful to eat as their flesh is beautiful, bright red and oily due to the fact that they are plankton eaters. Since kokanee feed mainly on these microorganisms and not other fish, their diet can be linked to their size.

The number one comment you will hear at the Lorimer Valley Trail bridge when the kokanee return is: "They aren’t very big, are they?" Although they may not be large, it is certainly apparent that Green Lake can hold its own when producing an abundant population of kokanee. When you have large populations of one species, they all compete for the same food source. This means there is sufficient food for everyone to get a little bit everyday, enough to function through life processes. With smaller populations, an overabundance of food means everyone gets more than they need, in fact more than they could ever want. This amounts to increased weight and length. This is, of course, reliant on a healthy plankton population where the same principles apply.

To most of us, a leaky septic tank sounds like a nightmare. To the plankton, and in turn kokanee, it is the epitome of an all you can eat smorgasbord. Nutrient levels in a lake can change drastically when septic tanks are installed or removed. This directly affects kokanee salmon populations. Linking communities to sewage treatment plants has affected kokanee populations in areas such as the Okanagan and Kootenay Lakes. It is also a theory for the disappearance of the kokanee salmon in Alta Lake. It will be interesting to see if the removal of septic tanks in the Emerald Estates area have any effect on the nutrient levels and the kokanee salmon population in Green Lake. It is yet to be seen.

Upcoming Events:

Saturday, October 5th — Whistler Bird Walk, 8 a.m . Meet at the bottom of Lorimer Road near the entrance to the Catholic Church. Novices and newcomers welcome. Please note later time! Call Michael Thompson (604-932-5050) for details.

Sunday, October 6th, 8 a.m. — Squamish Bird Count. Meet at the Howe Sound Inn & Brew Pub in Squamish. All levels of birders are welcome on this half-day event sponsored by the Squamish Estuary Conservation Society. Call Jim Wisnia (604-898-2000) for details.

Sightings and Memberships: NatureSpeak is prepared by the Whistler Naturalists. To become a member or to report noteworthy sightings of mammals, birds, or other species, contact Cathy Conroy, (604-894-1124).

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