The sockeye salmon fishing season will come to an early end on the upper Columbia River after this weekend.
Half of this year’s big run toward spawning grounds already has died because of warm water conditions, Washington Fish and Wildlife Department officials said Friday in announcing the early closure.
Anglers will not be allowed to keep sockeye they might catch from Rocky Reach Dam upstream to Chief Joseph Dam starting Sunday a half-hour after sunset.
The emergency rule does not affect fishing for summer chinook.
“Elevated water temperatures in the Columbia River have resulted in higher-than-expected mortalities of sockeye salmon returning to the Okanogan River,” fisheries officials said in the rule announcement.
Fish destined to return to the Okanogan River have swum up the Columbia River and are staging above the Rocky Reach Dam. The fishing closure for sockeye is needed, officials said, to protect these fish and allow as many survivors as possible to migrate to their spawning grounds when water temperatures improve.
“Never in my entire (29-year) career have I seen anything like this,” said Jeff Korth, the Fish and Wildlife Department’s regional fisheries manager in Ephrata. “A minimum of 300,000 adult salmon have died or will perish going up the river before reaching spawning grounds.
“We lost half of the run in the lower river after they hit the warmer-than-usual water. We’re lucky this is a big run.”
More than 500,000 sockeye salmon returned to the mouth of the Columbia River this year, among the largest runs in recent history. The fish are bound for the Snake River, Lake Wenatchee, and Okanogan River sockeye runs.
The warmer-than-usual water temperatures are promoting bacterial infections in the sockeye, Korth said.
“These salmon are constantly getting scraped, scratched and poked as they go over rocks and climb fish ladders and escape predators,” he said. “That’s not a big problem in cold water, but in warm water the bacteria that’s in an aquatic system gets around the wounds and proliferates faster. We’re seeing big gaping sores on these fish.”
Summer chinook, moving up the Columbia in record numbers, are not as much affected by the warm water, Korth said.
“Chinook are bigger and a little sturdier,” he said. “Their energy requirements are different. Sockeye are smaller salmon that race up the river. Their metabolic rate is going through the roof, and they’re hitting warm water that’s short on oxygen and they’re in trouble.
“Chinook are more likely to pull off into some sort of cooler water refuge and rest. They carry more body fat and have other factors that give them a chance of going farther upstream in these conditions.”
Communities along the river are concerned about decreased business under the closure. However, with chinook still available in big numbers, many anglers are likely to re-target their species and stay on the water.
“In reality, we may be cutting the business by just a few weeks,” Korth said. “Sockeye fishing was sensational earlier, but it’s starting to go by the wayside. It won’t be long before fish conditions won’t be as attractive.”
Oregon and Washington have both enacted emergency fishing rules for some waters that might help fisheries to some degree in this freak year of low snowpack and early runoff that’s ravaged the region’s summer river flows.
Sturgeon fishing was closed this month after dozens if not hundreds of the decades-old giants were found dead in mid-Columbia reservoirs. The sturgeon were stuffed with sockeye, and at least some of those sockeye were suffering from bacterial infections promoted by the warm waters. Korth said the warm water likely affected sturgeons’ metabolism.
A Lake Wenatchee sockeye season, which was scheduled to open last weekend, is still a possibility, Korth said. About 12,000 of the 106,000 sockeye forecast have moved over Tumwater Dam and into the lake system. “I’m hoping we’ll get 50,000. I’m optimistic we may have a season.”
Korth’s main concern is getting some sockeye up the Okanogan River to spawn in Canada and perpetuate the run.
The water temperature in the Okanogan River was 84 degrees this week, more than 12 degrees warmer than sockeye can survive.