Eklutna Tailrace coho: First imprinted release

"We are releasing coho at Eklutna Tailrace today at about 10 o’clock ” Alaska Department of Fish and Game (ADF&G) fisheries biologist, Samantha Oslund told me on Monday, “would you like to see it.”

“Was the department able to imprint them at Eklutna as you were hoping?” I asked.

“Yes, they’ve been there for the past week.”

Mat-Su anglers may know from a past column , that the department was considering taking coho salmon smolt raised at the Jack Hernandez State Sportfish Hatchery at Ship Creek in Anchorage, and then holding them in some of the outside raceways at Cook Inlet Aquaculture Association’s Eklutna Salmon Hatchery to imprint on water specific to that location.

“Imprinting,” has proven useful in increasing the number of adult salmon returning from hatchery releases at other remote release sites.

ADF&G has been imprinting king salmon smolt released at the Eklutna Tailrace for several years now, however this is the first time imprinting was being utilized for Jack Hernandez coho smolts released at the tailrace. I have expressed an interest in seeing this practice use to hopefully better maximize the number of adult coho salmon returning to this terminal sportfishery area. So I made it a point to show up, and brought my wife along to photograph as well.

After arriving at the tailrace one of the first questions I asked Samantha, “Has the Department been able to measure an increase in returning adult king salmon to Eklutna Tailrace, that could be attributed to imprinting them before release?”

“We have not really had a way to document that,” Samantha replied, “but we have continued the practice, because it could be helping our Eklutna king salmon return.”

After looking at clouds of young fish filling the two raceways that were being released into the tailrace I asked, “Do you know how many coho smolts you are releasing today?”

“I think about 150,000,” Samantha replied, “but I am not sure of that number.”

“Are they about 4 1/2 inches long this year?” I asked, thinking that was about the size of coho smolts released last year at the tailrace.

“Yes, they are somewhere in that ballpark,” fisheries biologist, Oliver Querin replied, “but these are some of the best looking coho smolt I’ve seen, and some of them may be 6 inches long.”

After hatching out during 2025 spring this batch of coho had been raised through the fingerling state during the 2025 -2026 winter at Jack Hernandez Hatchery and were being released on May 12, 2026. The adult return from this release should be arriving back after spending just over a year in saltwater during July, August and possibly early September 2027. I and many other Mat-Su anglers will be excited to see if we can detect a noticeable increase in returning Eklutna Tailrace coho salmon — in 2027.

NOTE: A later search of the ADF&G stocking page revealed over 230,000 coho stocked at the tailrace on May 7 and 8, 2025, however the 2026 stocking numbers and size had not been inputted - at that time.

Water Concern While the coho smolts were being released there was a noticeable lack of downstream flow in Eklutna Tailrace. According to ADF&G staff, Eklutna Power Plant had notified them that water throughput at the Power Plant would be cut the following day for annual maintenance that may run through the end of May. In the past when the flow has been cut for maintenance during May, visible current flow down the Knik River side-channel has been practically nonexistent. My wife and I ventured down to the side-channel and noticed that same appearance on Tuesday. One has to wonder how that will effect the coho smolts that were just released. Will gulls and eagles catch and eat a large number of the small fish before they can migrate down the extremely shallow side-channel to the main river? How long will the small coho inhabit the deeper tailrace, whose water stagnates without flow, before swimming down river?

Little Susitna River Weir — also on Tuesday May 12 ADF&G staff were out at Little Susitna River starting efforts to install the weir at the new further upstream location first used last year. The Department hopes to enumerate the entire 2027 king salmon return and the entire 2027 coho salmon return through use of the weir at this new site. The results from last year indicate that this new location maybe a considerably more stable opportunity to measure Little Susitna River salmon returns (of all species) throughout the entire late May to early September season.

Deshka River Salmon Enumeration — ADF&G hopes to start counting king salmon a bit later in May at the same Deshka River weir site that has been use for the past decade. A new wrinkle this year, if water is too high to install the weir in a timely manner, ADF&G staff may start the season using a sonar counter to measure the king salmon return. Sonar is also being considered as a possible means to measure coho salmon returns at times when high water flows may impede counting fish through the weir.

Alexander Creek Northern Pike Control Project — Samantha Oslund told me the Department had already flown staff members to get started on this project / in combination the department will be working toward eradicating invasive Elodea from portions of Sucker Lake within the Alexander Creek drainage.

Memory Lake / Knik Lake stockings — after pike eradication efforts through rotenone treatments last fall Oslund identified these two lakes as priority locations she would like to see stocked with catchable-sized fish as soon as possible.

Fish On!

While Andy Couch is a member of the Matanuska - Susitna Borough Fish and Wildlife Commission and the Matanuska Valley Fish and Game Advisory Committee the thoughts and opinions expressed in this column are his own - unless noted otherwise.