Lake Sammamish kokanee need long-term fix

September 25, 2012

By Dallas Cross

Dallas Cross

Oncorhynchus nerka, our kokanee salmon in Lake Sammamish, is a threatened native species with greatly reduced numbers spawning in streams feeding the lake.

Most of their historical spawning areas are now denied by barriers or degraded as a result of land development.

Until recently, Lake Sammamish kokanee have not been included with other salmon species in conservation measures and have been low in profile for public concern.

For the past several years, an effort of the environmentally concerned and governmental communities adjacent to Lake Sammamish have participated in defining the problem, setting goals and taking action to address the threatened loss of the kokanee.

Most visible in these efforts are the members of the Lake Sammamish Kokanee Work Group, which includes watershed residents, the Snoqualmie Tribe, King County and the cities around the lake, the Washington Department of Fish and Wildlife, the U.S. Fish and Wildlife Service, Trout Unlimited, Save Lake Sammamish and the Friends of Pine Lake.

The goal of consensus is to restore the kokanee population in Lake Sammamish to a level that can successfully continue through natural reproduction and again provide sufficient numbers for fishing.

Immediate goals of the Kokanee Work Group encompass two approaches — supplementation of native kokanee populations in the lake and restoration of spawning habitat. There are some current actions and planned actions that may offer hope for our historically signature fish of Lake Sammamish and its watershed creeks.

Supplementing the kokanee population — an interim fix

The Issaquah Salmon Hatchery has engineered and employed special incubators to raise kokanee fry from fertilized eggs for the past three years.

Kokanee eggs and fry have been incubated and raised in waters hauled in from Ebright, Laughing Jacobs and Lewis creeks, in which the spawning adults were captured. The ear bones of the fry have been coded through temperature changes so that returning adults can be identified as to creek source and year of hatching.

It is the hope that in future years we will have spawning kokanee adults from which fish biologists can retrieve their marked ear bones and measure the first successes of the hatchery program. This supplementation program is scheduled to continue through 2021.

The longer term supplementation goal is to reintroduce kokanee to streams that have the habitat potential to support spawning, but, based on very limited data, spawning kokanee have not been recorded.

These creeks could include Pine Lake, Zaccuse, George Davis, Issaquah (including its forks), Tibbetts, Vasa and Idylwood, and Phantom Lake. Reintroduction would involve placing marked fry from one of the existing populations into a new creek and monitoring for their return in three or four years.

Remediating the habitat — a lasting fix

Perhaps current activities at Ebright Creek exemplify what creek rehabilitation should start to look like. Just east of the stream crossing at East Lake Sammamish Parkway a partnership is moving forward with a project that will dramatically improve conditions for spawning kokanee.

Key resources for implementing this project are coming from landowner Wally Pereyra, the city of Sammamish, the National Fish and Wildlife Foundation, the King Conservation District, King County, the U.S. Fish and Wildlife Service, Trout Unlimited and Friends of Pine Lake.

“The project will achieve the following objectives: design, permit and implement a project to re-establish access to high quality spawning habitat above the project site and improve channel and riparian habitat conditions at the project site; establish and model an effective cooperative partnership with a landowner in support of kokanee conservation; and monitor effectiveness of the project,” the project request states.

The project will remove and replace a culvert that has impeded fish passage for more than 70 years, reroute the stream over suitable gravel beds, and restore the riparian areas surrounding the creek on Pereyra’s property.

It is estimated that this action will restore access to high-quality spawning habitat in areas upstream of the culvert and increase spawning areas in Ebright Creek by approximately 25 percent.

This project is under construction and well under way toward giving a welcome home greeting to the signature fresh water salmon of Lake Sammamish when they return to Ebright Creek this fall.

Keeping track — census surveys

Only four creeks feeding Lake Sammamish are known to have kokanee returning to scrape out gravel redds in which to lay and fertilize eggs. In fall and winter, spawning season census counts have been routinely made by wildlife biologists working with citizen volunteers in Ebright, Lewis, Laughing Jacobs and Pine Lake creeks.

To complement this, the emerging kokanee fry are counted in the spring by the Bellevue-Issaquah Chapter of Trout Unlimited and its volunteers in Lewis and Ebright creeks. To broaden coverage, additional fry traps are needed and the chapter is raising funds to construct more.

These census numbers are the values from which revival of kokanee in the lake will be measured. To date, the limited census numbers do not support hope for a spontaneous revival of kokanee in the lake.

The Kokanee Work Group is calling for and will train citizen volunteers to conduct weekly census counts of spawning kokanee in some tributary creeks this fall.

The Bellevue-Issaquah Chapter of Trout unlimited will lead recruiting and registering volunteer counters.

Reach Dallas Cross at FishJournal@aol.com or www.fishjournal.org. View previous articles and comment on this column at www.issaquahpress.com.

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