Matanuska-Susitna Borough

Salmon Research: Jim Creek Coho Salmon Weir

Scope

This project will continue a weir program initiated in 2015, currently funded through 2016.  A weir at Jim Creek allows the department a means to enumerate the spawning escapement of coho stream on a system that supports one of the largest coho fisheries in the state.  Escapement information for Jim Creek coho salmon is needed by ADF&G to assist with managing fisheries that utilize this stock.  All salmon will be identified and counted as they swim through a live trap or as they are released upstream of the weir after being sampled for age, length and sex.  Aside from improving sport fishery management, an accurate measure of the escapement may allow evaluation of the reliability of escapement index counts currently being conducted on McRoberts Creek and Upper Jim Creek by post season foot survey.  The weir count may also allow the department to assess the current level of exploitation within the sport fishery as well as reconstruct total run and evaluate exploitation of this stock in various commercial fisheries if combined with the marine coho GSI and genetics baseline programs currently underway.

Timeline: November 2015-March 2018

Project Benefits

Project Status

ADF&G operated a floating resistance-board weir on Jim Creek at about river mile 0.5 between July 18 and September 24, 2017. A total of 5,646 coho salmon were counted through the weir.  The timing of the run was approximately five days late, based on the mean mid-point historical passage.  The exploitation of the sport fishery in 2017 will be assessed using final results of the Statewide Harvest Survey which will be available in fall 2018.  Additionally, a total of 100 tissue samples were taken from adult coho at the weir to be used toward the genetic baseline.   These results will be reported in an Area Management Report for the Recreational Fisheries of Northern Cook Inlet, 2017-2018, to be published in late 2019-early 2020.