A multi-year salmon and steelhead hooking mortality study begins this month in the lower Cowlitz River, research that state officials hope to use in managing sport fisheries throughout the Columbia River Basin.
The research will look at how hook-and-release mortality varies by gear type (bait, lures, treble hooks, single barbless hooks), angling technique (gear and fly fishing) and water temperature.
It will cover spring and fall chinook, winter and summer steelhead and coho.
Mount Hood Environmental of Boring, Ore., will lead the study with help from the Washington Department of Fish and Wildlife, Tacoma Power and sport anglers on the Cowlitz downstream of the barrier dam.
Money for the study comes from the $8.25 fee paid by sportsmen to fish for salmon or steelhead in the Columbia River or its tributaries.
The citizen-based Columbia River Salmon and Steelhead Advisory Board has approved spending $134,000 in 2017-18 to start the study.
“If we are going to continue to be able to have hatchery-based recreational salmon and steelhead fisheries throughout the Columbia River Basin we must be able to accurately assess the impact of those fisheries on the wild populations, most of which are ESA-listed stocks,’’ said Ed Wickersham of Ridgefield, chairman of the Columbia River Salmon and Steelhead Advisory Board.
“Virtually all of our recreational fisheries are conducted where listed salmon and steelhead are present and so it is imperative to be able to accurately assess the mortality associated with the particular fishery.’’
The study is designed to take place over three years, however the information from the first year of data is not contingent on financing in subsequent years.
The lower Cowlitz River was selected due to its large hatchery-origin salmon and steelhead programs plus the availability of two hatcheries on the stream to hold fish and measure their survival.
Most of the fishing will be done with 10 miles of Mayfield Dam.
“The reason the Cowlitz River was chosen is that it has good numbers of salmon and steelhead, a wide array of species, and a assorted range of river temperatures over the year,’’ Wickersham said.
State scientists contend the study on the Cowlitz is a far more efficient way to develop valid mortality rates than similar studies on a number of rivers.
“The results of this study should then be able to be applied to a myriad of recreational fisheries across the basins,’’ he said.
Wickersham said the study results may be a boost to sport fishing.
“There is also a thought that the current mortality rates may be too high, so there is a possibility that this study may result in increased recreational opportunity,’’ he said. “Regardless, the study will provide a high level of confidence in the mortality rates that are being used.’’
The study has annual angling targets of 65 fall chinook, 87 coho, 87 spring chinook, 197 winter steelhead and 235 summer steelhead.
To capture enough fish, a local guide will be hired, plus volunteer angling and tagging events or derbies are envisioned.
Fish will be tagged, then recovered at the Cowlitz Salmon Hatchery fish separator or by anglers.
Salmon and steelhead not caught on hook and line will be tagged and released also to serve as a control group.