The Alaska chinook salmon/pink salmon relationship

Alaskans, familiar with salmon harvests, salmon spawning escapement numbers, and current sizes of salmon harvested, should readily agree there has been significant declines in both population numbers and size at maturation of Chinook (king) Salmon in Alaska. The largest of Alaska’s salmon species, Chinook, has officially been recognized as the state fish since 1963. According to information posted on the Alaska Department of Fish and Game (ADF&G) website: The Chinook salmon is perhaps the most highly prized sport fish in Alaska and is extensively fished by anglers in Southeast Alaska and in Cook Inlet (South-central Alaska). Trolling with rigged herring is the favored method of angling in salt water, while lures and salmon eggs are used by freshwater anglers. The annual Alaska sport fishing harvest of Chinook salmon from 1989 to 2006 averaged 170,000 fish. During that period, 60% of the sport fish harvest of Chinook salmon was taken in South-central Alaska, 26% in Southeast Alaska, and 4% in the Arctic-Yukon-Kuskokwim area. Alaska's sport and personal use fisheries worth more than 500 million dollars annually.

Subsistence Fishery information posted on the same ADF&G webpage documents:

Annual Chinook salmon harvests by subsistence and personal use fishers in Alaska averaged 167,000 fish from 1994 to 2005. The majority of the subsistence harvest is taken in the Yukon and Kuskokwim rivers.

The Dramatic Chinook Decline:

After the last Upper Cook Inlet peak in Chinook salmon populations during the 1980s and early 1990s king salmon returns to Northern Cook Inlet and the Mat-Su Valley declined in the mid 1990s, and bait use (while sport fishing for king salmon) in many local freshwater locations was either restricted or entirely closed by the late 1990s. With the switch to artificial lures Northern Cook Inlet / Mat-Su Valley sport Chinook salmon fisheries continued to produce strong angler participation levels with somewhat reduced harvests until ADF&G started noticing a more dramatic decline in ocean production of Chinook Salmon starting in 2007. Since 2007 the Chinook Salmon decline throughout all of Upper Cook Inlet has triggered an increasing number of sport, personal use, and commercial fishing restrictions and closures both in fresh and salt waters. In 2022 and 2023 no Chinook salmon sport harvest was allowed in all of Northern Cook Inlet except for the fisheries supported by hatchery releases at Eklutna Tailrace and Ship Creek.

Chinook Subsistence Declines:

Although I have not gathered the data — I’ve been quite aware of Chinook Salmon shortages, so severe, that at times, major subsistence Chinook salmon fisheries were closed for extended periods on the Yukon, Kuskokwim, and Copper rivers. Most severely hit in Chinook population size and spawning escapement numbers has been the Yukon, which has also seen the most prolonged Chinook declines. Recently, the Alaska Board of Fisheries recognized Nushagak River Chinook salmon as a Stock of Concern.

Relation to Alaska Pink Salmon Abundance Multiplied by Hatchery Production

I’ve been following well-researched, well - documented articles posted by Craig Medred News on this issue for a few years now. Craig posted some excerpts and his own thoughts and others’ comments about a scientific study on this issue. Consider reading this post — below are some excerpts that may spur interest:

Major Study Links Pink Salmon and Ocean Chaos

Pink salmon and the hatcheries (that) helped boost their numbers to never-before-seen highs were Thursday singled out for disrupting the ecosystem of the North Pacific Ocean to the detriment of other species of salmon, seabirds, whales and more in a peer-reviewed study published in the journal Marine Ecology Progress Series (MEPS).

The study . . . concluded that “the evidence is consistent and strong that pink salmon can exert competitive dominance for common-pool prey resources shared by four forage fish species, all five species of Pacific salmon and steelhead trout, and 11 species of seabirds.

“We examined the time series of annual Chinook salmon commercial harvests in Alaska and British Columbia (Canada) from 1952 to 2021. Commercial harvests reflect fishing effort based on abundance predictions and fishery regulations and can provide a first-order approximation of abundance….Consistent with the hypothesis that pink salmon affect Chinook salmon, we found that harvest trends during the 70-year period were opposite those of pink salmon abundance trends.”

Craig’s summary: “Simply put, the research shows that when pink salmon numbers go up in the ocean both the size and number of king salmon go down.”

Below Craig’s summary is a graph showing the relationship between chinook salmon harvest and pink salmon abundance and a second graph depicting the relationship between chinook salmon size and pink salmon abundance for the years 1952 - 2021.

Participation / Learn More: The Alaska Board of Fisheries Hatchery Committee will host a public meeting starting at 8:30 a.m. at Egan Convention Center in Anchorage on Saturday October 14, 2023: I consider this an educational meeting and plan to attend in person and possibly participate in the discussion or at least express some of my thoughts to Hatchery Committee members. There is also a live video feed in the linked meeting notice above for those who would like to follow the meeting online.

Fish On!

Andy Couch is a local fishing guide, Matanuska Valley Fish and Game Advisory Committee Member, and Matanuska-Susitna Borough Fish and Wildlife Commission member. Opinions expressed in this column are his own, unless otherwise noted.