Copper River forecast still off from historical returns

  • Copper River sockeye harvested during the first fishing period on May 16, 2019, are seen after delivery to 10th and M Seafoods in Anchorage. After a historically poor harvest of kings and sockeyes in 2020, state biologists are forecasting a slight rebound in 2021. (Photo/Courtesy/10th and M Seafoods)

State research biologists expect the famed Copper River salmon fishery to rebound from what was nearly a lost season in 2020, but runs for the river’s high-value species are still expected to fall well short of historical averages.

Just more than 1.3 million sockeye are projected to return to the Copper River this year for a corresponding allowable commercial harvest of 672,000 fish, according to the Alaska Department of Fish and Game’s 2021 Prince William Sound and Copper River Salmon Forecast.

The 2021 return of Copper River king salmon — some of the most sought-after salmon on the planet — is pegged at 37,000 fish, which is the midpoint in a run forecast range of 22,000 to 53,000 kings. If accurate, the 37,000-fish estimate would provide for an available harvest of 13,000 kings by all user groups.

The 10-year average king return to the Copper is approximately 48,000 fish and the forecasted total allowable harvest of 13,000 kings for 2021 matches the average commercial catch over the past decade, according to ADFG records.

The forecast for wild sockeye, which make up the bulk of the Copper River run, is 37 percent less than the recent average of nearly 2.1 million wild fish and just 51,000 sockeye are projected to return to the Gulkana Hatchery; that’s 81 percent less than the 10-year average.

Additionally, the allowable commercial harvest of 672,000 sockeye based on those returns is 46 percent less than the recent average harvest of more than 1.2 million Copper River sockeye.

Copper River king and sockeye salmon are particularly valued for their high fat content and because the fishery that starts in May is among the first to offer large volumes of fresh salmon each year.

The subpar preseason projections follow what was a dismal 2020 Copper River commercial salmon fishery. Poor catches during the initial May openers forced managers to close fishing for much of June when the largest pulses of sockeye typically enter the river.

The 2020 Copper River commercial season ended with a harvest of 98,294 sockeye and 5,850 kings. Coho made up the majority of the 269,966-all salmon harvest in the district last year.

The extremely poor overall return of roughly 630,000 sockeye — ADFG commercial harvest plus in-river figures — to the Copper River last year is weighing on the expectations for this year.

According to the forecast report, the wild sockeye run estimate is largely based on the number of sockeye that returned in prior years but are from the same brood years as the majority of the fish returning this year.

Predictions for the youngest sockeye that spend either one year rearing in freshwater and one at sea or those that spend minimal time in freshwater and three years in the salt water are based on the mean returns for those age classes during the last five years.

However, a very poor 2018 sockeye run that finished with a commercial harvest of just 44,400 fish and an in-river count of 701,577 did not correlate to a weak return the following year. Nearly 1.3 million sockeye were harvested in the Copper River district in 2019, part of a total run of roughly 2.3 million fish.

The 2021 Copper River king forecast is primarily based on spawner-recruitment trends for the Copper River system since 1999, according to the report.

While the forecast for the 2021 Copper River salmon season is somewhat dim, it is not expected to translate to the adjacent Prince William Sound fisheries.

Coghill Lake in western Prince William Sound is expected to see 282,000 sockeye, which would be 45 percent greater than the 10-year average of 194,000 fish. A return of that size would also allow for an all-user harvest of 252,000 sockeye using an escapement target of 30,000 fish.

ADFG biologists also expect it will be a particularly strong year for wild pink salmon runs in the sound. Odd-numbered year pink runs are typically much larger in Prince William Sound for the species with a very strict two-year life cycle and this year nearly 19.2 million wild pink salmon are forecasted to return to river systems across the sound, which would be 27 percent greater than the recent odd-year average of about 15 million wild pinks.

Nearly 12 million wild pink salmon have been harvested sound wide on average during the last 10 odd years, according to ADFG data.

Despite the strong official forecast figures, the report notes that there is “considerable uncertainty” as to the spawning success of wild Prince William Sound pinks in 2019 due to the extreme drought conditions across much of southern Alaska that year, which would directly impact this year’s return.

“Pre-spawn mortality, lack of water in spawning streams, and high water temperatures were observed in 2019. This forecast does not integrate environmental indices or other indicators of spawning success and the 2021 prediction takes no account of the anomalous conditions observed during the parent year,” the report states.

Many millions of hatchery-reared pinks also return to Prince William Sound during odd years as well.

Lower Cook Inlet

On the other side of the Kenai Peninsula, ADFG researchers are predicting a commercial harvest of just more than 2.1 million salmon across all species in lower Cook Inlet waters this year.

The 2021 commercial harvest would be below the 2.5 million salmon harvested last year and the roughly 2.4 taken in 2019, but does not account for nearly 1 million combined hatchery sockeye and pink salmon expected to be harvested for cost-recovery purposes.

The vast majority of salmon harvested in lower Cook Inlet are pink salmon — pinks comprise 1.8 million of the 2.1 million-fish common commercial harvest projection — in contrast to upper Cook Inlet fisheries that predominantly target sockeye.

Elwood Brehmer can be reached at [email protected].

03/10/2021 - 9:14am