Fisheries, Subsistence, and Habitat
Publications Searchable Database

Search Again
Division: Sport Fish
Title: Ninilchik River Chinook salmon assessment, 2002 and 2003.
Author: Begich R. N.
Year: 2007
Report ID: Alaska Department of Fish and Game, Fishery Data Series No. 07-41, Anchorage.
Abstract: During 2002 and 2003, wild (naturally-produced ) and stocked Chinook salmon Oncorhynchus tshawytscha runs to the Ninilchik River were assessed with a weir to determine the stock composition of total escapements and to determine if Chinook salmon stray to the Ninilchik River from three stocking locations in Kachemak Bay. The stock composition of the Chinook salmon harvest was estimated for the third weekend open for sport fishing in the Ninilchik River below the Sterling Highway. The total escapement of wild Chinook salmon was 1,340 fish in 2002 and 1,127 fish in 2003. The 2-year average wild stock contribution to the escapement was 77%. Wild stock escapement corresponding to the sustained escapement goal (SEG) monitoring period was 655 fish during 2002 and 393 fish during 2003. Stocked escapements were 395 fish in 2002 and 336 fish in 2003. The average contribution of stocked fish to the escapements was 23%. The majority of the wild Chinook salmon escapement consisted of 3-ocean fish, 59% (SE = 3%) and 57% (SE = 3%) in 2002 and 2003, respectively. For the stocked Chinook salmon escapements, 3-ocean fish accounted for an estimated 48% (SE = 3%) of the 2002 and 41% (SE = 4%) of the 2003 escapements. Stock composition of the immigration varied significantly over the duration of the runs to the weir. Median date of weir immigration for wild fish was July 17, 2002 and July 4, 2003; the median date for stocked fish was July 24, 2002 and July 17, 2003. Two hundred seventeen coded wire tags were decoded from 226 Chinook salmon that were sacrificed at the weir. No strays from Kachemak Bay stocking programs were detected, 212 tags were from fish stocked at the Ninilchik River, and 5 were from the Alaska Department of Fish and Game, Crooked Creek stocking program (tag expansion of 1.0), a tributary of the Kasilof River. The contribution of stocked Chinook salmon to the third weekend sport harvest sampled in the lower river was 22% (SE = 9%) during 2002 and 32% (SE = 12%) during 2003. Continuing the Chinook salmon assessment at Ninilchik River weir is recommended to fully understand the relation between inseason management actions designed to increase exploitation of hatchery stock surpluses while maintaining wild stock escapements.
Keywords: Chinook salmon Oncorhynchus tshawytscha, Ninilchik River, wild stock, hatchery stock, run, escapement, weir, contribution, adipose finclip, and coded wire tag.