Mat-Su salmon habitat partnership tours Deshka River

On Tuesday Aug. 23 I had the good fortune to participate in the Mat-Su Salmon Habitat Partnership’s site tour of Deshka River. It was a good opportunity to visit and share different perspectives with scientists, Alaska Department of Fish and Game staff, and some local and state policy makers, along with some river guides, and native leaders all interested in Mat-Su’s precious salmon resource. One of the highlights of the trip for me was learning more about the historical use of Deshka River by natives, and the extent to which they utilized this resource, and how they were able to preserve and store the harvest for extended periods of time.

Deshka River is a clearwater tributary to the vast Susitna River drainage that hosts about 20% of the entire annual Susitna Drainage king salmon return and also hosts approximately 20% of the entire annual Susitna Drainage coho (silver) salmon return. It is the only Susitna River tributary stream where adult escapements of these two extremely important salmon species have been enumerated in season. The inseason numbers of Deshka River king salmon and coho salmon have been important in salmon management throughout the entire Susitna River drainage. From age data collected at Deshka River weir the Alaska Department of Fish and Game (AF&G) has been making king salmon return projections useful in management of king salmon throughout the drainage. While king salmon returns throughout the Susitna Drainage do not swing up and down in direct relationship, the department has found that a poor, average, or strong forecast for the Deshka River king salmon return is a good indicator of similar strength king salmon returns in other Susitna River tributary streams. In addition, when there are enough king salmon to provide more liberal methods and means, and harvest opportunity at Deshka River, other Mat-Su sport fisheries for wild king salmon (like Little Susitna River or Yentna River tributary stream may also be able to provide harvest opportunity at the same time. This is in part because the Deshka River sport fishery with often more liberal regulations and harvest opportunities can buffer sport fishing effort on streams with lower king salmon populations and more restrictive regulations. Deshka River often provides the largest king salmon fishery and the largest coho salmon fishery on the Susitna River drainage in terms of both sport angler participation and harvest. This semi-remote fishery is primarily accessible by boat or airplane.

Sue Mauger with Cook Inlet Keeper working with the U.S. Fish and Wildlife Service has been monitoring water temperatures at several sites along the Deshka River for several years now. This work has revealed locations of several areas with groundwater inflows that help cool the lower Deshka River and assist adult salmon in their upriver migrations during times of low stream flows /high water temperatures. Some of these cooler water refuge areas are also utilized by juvenile salmon rearing in waters that might otherwise be too warm for their existence during the same times of low steam flows /high water temperatures. Locations of these cooler water infusion areas have been documented to assist in future land / water use decisions that may be made along the river.

Upstream salmon migrations of both king salmon during the early half of the summer and coho salmon during the later half of the summer show a pattern of upstream weir passage consistent with higher stream flow levels /cooler water temperatures. Consequently a constant water temperature monitoring reading at the Laub -Elkins property below the Deshka River weir is now available to ADF&G to assist with inseason salmon management decisions for the river.

Covid-19 travel restrictions and health protocols caused a reduction in nonresident angler participation and fishing license and king salmon stamp purchases whose impact is still being felt in the Mat-Su Valley. As a result of the reduction in fishing license and king salmon stamp sales and a loss of federal match monies the Deshka River weir has been funded for only a portion of the coho salmon return for each of the past 3 years. During each of those years with early removal of Deshka River weir there has been uncertainty to whether the Deshka River coho salmon escapement goal would have been met during all 3 years. Similar to Deshka River king salmon numbers, coho salmon escapement numbers from Deshka River weir have been used by ADF&G to make inseason management changes for other Susitna River drainage coho salmon fisheries. For these reasons, returning Deshka River weir to installation and use throughout the entire coho salmon return is a priority item for ADF&G when funding levels increase to previous levels — a thought echoed during the tour by ADF&G Deputy Commissioner Ben Mulligan.

Deshka River is part of the Recreational Rivers Plan which also includes Alexander Creek, Talachulitna River, Lake Creek, Little Susitna River, and Talkeetna River. The Recreational rivers plan is being considered for updates at this time, to better reflect possible changing interests from the public. This plan was originally established to protect premium salmon habitats and provide recreational opportunities for broad public use. Those are two intents I would like to see maintained in any updates to the plan.

Mat-Su anglers may want to consider a free membership in the Mat-Su Basin Salmon Habitat Partnership and participation in future events. If interested, or to learn more, contact Jessica Speed, project manager, at 907-575-7818

Fish On!

Andy Couch is a Mat-Su Valley fishing guide who primarily targets ocean-run salmon during summer months. You can read daily fishing reports on his Fishtale River Guides website: https://www.fish4salmon.com