Strong coho salmon run predicted
March 15, 2011
By Warren Kagarise
State offers strong forecast for chinook, coho after historic low
State forecasters predict a strong coho salmon run in the fall, after a dismal run for the species to Issaquah Creek and other Puget Sound streams last year.
The state Department of Fish and Wildlife expects 981,216 wild and hatchery-raised coho to reach Puget Sound streams — including 28,606 fish to the Lake Washington watershed. Issaquah Creek is included in the Lake Washington forecast, although the state does not break out data for the stream.
The forecast for Puget Sound includes about 367,000 more fish than last year. Though the coho run ended late last fall, managers continue to tally the total for the 2010 coho run.
The forecast comes after a tough year for the salmon species.
Teams at the Issaquah Salmon Hatchery trapped a mere 475 coho last fall. The coho count at the Hiram M. Chittenden Locks in Ballard barely crested 3,600 fish — far less than the 6,000 coho recorded during the last slump in 2002.
The inexplicable shortfall prompted the Issaquah hatchery to turn to a state hatchery in Snohomish County for about 750,000 eggs to send to schools and co-ops.
“I know that we kept thinking we were going to see more, and it just kept getting worse and worse,” Gestin Suttle, Friends of the Issaquah Salmon Hatchery executive director, said after the state announced the forecasts in early March. “It’s not an exact science. We really can’t be sure until they start coming back and we see how many make it. I’d rather see this. It’s more encouraging and it’s a positive forecast.”
Pacific Ocean is wild card
Biologists offered theories about the drop-off. Perhaps poor ocean conditions related to temperature or oxygen levels affected coho in the Pacific Ocean. Maybe predation, or a lack of food sources, led to the decline.
Issaquah Hatchery Foreman John Kugen said salmon managers should gain a better understanding for the 2011 coho run after the fish start to reach the Ballard locks.
“Even then, you don’t know which rivers they’re going to go into,” he said. “It might look like you have a gangbuster for Puget Sound, but you can’t say that all of the rivers are going to be having a good run.”
In order to formulate the annual forecasts, scientists measure the number of wild smolts, or juvenile salmon, departing fresh water at locations around Puget Sound. Hatcheries also record the number of juvenile salmon released each year.
“Obviously, there are some areas where we don’t have traps, and we have to extrapolate for those areas based on historical ratios of returns and production,” Puget Sound Salmon Manager Steve Thiesfeld said.
The wild card in the annual coho forecasts is survival in the ocean environment.
“You’ll often hear salmon managers talk about the marine environment as the black box, because there really is no way to go out in the marine environment and do any kind of test fishing or sampling that yields reliable run size updates or estimates of how those runs are doing,” Thiesfeld said.
Managers then use the forecast information to set recreational fisheries in the sound.
The summer and fall chinook salmon returns to Puget Sound should reach about 243,000 fish — more than the 226,000 fish projected for last year.
State predicts ‘good year of fishing’
The local hatchery spawns both coho and chinook. The forecast “probably bodes well for Issaquah,” Suttle said.
Forecasters also expect Pacific Ocean fishing opportunities for chinook and coho to be available in the summer months, due to the strong forecasts.
“Last year, fishing was good for chinook and fair for coho,” state Ocean Salmon Fishery Manager Doug Milward said in a statement. “The number of salmon available for this summer’s ocean fishery is expected to be similar to last year, so anglers should see another good year of fishing.”
Forecasters also expect a strong pink salmon run. The state forecast 6 million pink salmon to reach Puget Sound. The downtown Issaquah hatchery does not spawn pinks.
“Pinks pretty much take care of themselves,” Kugen said.
Forecasts for chinook, coho, sockeye, pink and chum salmon mark the starting point for setting salmon-fishing seasons in Puget Sound and elsewhere. The state wildlife agency and American Indian tribes develop the forecasts, and then fishery managers finalize seasons in mid-April.
Agency Director Phil Anderson said department staffers, tribal co-managers and constituents work together to develop fisheries in order to meet conservation goals and offer fishing opportunities on wild and hatchery-raised fish. Cuts to the state budget also mean the agency has a smaller staff to manage fisheries.
“We will continue to design fishing seasons that not only meet conservation goals for salmon, but also minimize impacts to other species,” he said in a statement. “It is important that we take into account the entire ecosystem when managing our fisheries.”
Warren Kagarise: 392-6434, ext. 234, or firstname.lastname@example.org. Comment at www.issaquahpress.com.