Friday, February 1, 2013

Lake Sammamish Kokanee Salmon Observed in 13 Streams

  Map of Lake Sammamish tributaries. Those
  in red are tributaries where kokanee have
  rarely been observed in recent years until
  2012. Those in black are the four main
  spawning tributaries.
This past year’s return of kokanee to Lake Sammamish tributaries saw several thousand spawners in the four main tributaries (Lewis, Ebright, Laughing Jacobs, and Pine Lake Creeks). In addition, kokanee spawners were unexpectedly observed in other tributaries--George Davis and Zaccuse Creeks on the east side; Issaquah, East Fork Issaquah, Tibbetts, Pickering, and Schneider Creeks in the south end; and Vasa and Idylwood Creeks on the west side of Lake Sammamish. For most of these additional creeks, spawning kokanee have been recorded in the past but have not been observed in recent years. In two of the creeks (Pickering and Schneider) kokanee do not appear to have ever been observed before 2012.

Agency staff members from King County, WDFW, and USFWS, as well as private landowners, conducted periodic surveys of these creeks in 2012. In addition to counting the live spawning fish, surveyors also collected kokanee carcasses in order to remove their otoliths (ear bones). The otoliths will be analyzed in the lab to determine if fish originated from Issaquah Creek State Hatchery or were naturally produced. Tissue samples were also taken from some of the fish to determine their genetic make-up.

This past year’s results indicate that Lake Sammamish kokanee are spawning in tributaries on all sides of the lake, underscoring the need to protect and restore as many tributaries as possible in order to sustain this native population.

   Kokanee spawning area in Schneider
   Creek. Prior to 2012, kokanee were
   not known to use this tributary.


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