Millions of pink salmon are bound for Washington rivers and streams this year. Biologists are worried that when they return, they might find the water too warm and shallow for spawning and cause more problems for fish already struggling in drought conditions.
The Washington Department of Fish and Wildlife is estimating that almost 6.8 million pink salmon will make it to Puget Sound this year.
Of those, 1.6 million are forecast for the Snohomish River, 600,000 for the Skagit River and 210,000 for Stillaguamish River.
The 2015 pink salmon fishing season is expected to be one of the best in years. It started in most saltwater areas on July 1.
“It’s a very strong run of pink salmon this year,” said Ryan Lothrop, a salmon fishery manager for the Fish and Wildlife. “Conditions have been very favorable during the last few cycles.”
The pinks have a two-year life cycle so they are expected to return to their native rivers and streams almost exclusively on odd years.
In 2013, the state estimated that 6.3 million pinks would return but biologists believe 8.8 million showed up. In 2011, the state forecasted that 6 million pinks would end up in Washington waters but found about 5.7 million arrived.
The number of pinks in Puget Sound has increased dramatically in the past decade but biologists aren’t exactly sure why, Lothrop said.
Pinks are the most abundant and smallest salmon species in the sound, averaging about four pounds. They are also known as “humpies” because the males develop a humpback when they return to the rivers to spawn in the late summer and early fall.
They lay eggs in the gravel of the riverbed. In the late winter, the eggs hatch and juvenile pinks head to the salt water, where they grow until they return to the river to spawn and die.
Chinook, coho, steelhead and sockeye stay in the rivers longer than pinks.
Mike Crewson, a salmon biologist for the Tulalip Tribes, said he believes the pinks spending a shorter amount of time in fresh water is one reason they’re doing better than other salmon.
Because the pinks leave the river soon after hatching, he said, they avoid many of the problems other salmon face, such as shallow water, higher temperatures and pollution in the rivers.
They go to the salt water in the winter, where they are able to eat before the water conditions change and less desirable food is produced, Crewson said. The pinks also seem to be responding better than other salmon to the changing marine environment, he said.
With plentiful food in the ocean, the pinks are able to grow and return to the rivers to spawn, which results in more fish. Predators can’t catch healthier fish as easily, which also benefits the pinks.
Biologists believe the lack of quality freshwater habitat for other salmon to spawn and rear in is contributing to their low survival rates.
With pollution, climate change and now a drought, bringing back healthy salmon populations is an uphill battle, Crewson said.
The state and the tribes work together to manage all salmon species. They figure out how to manage salt and freshwater fisheries so enough salmon are able to make it back to their spawning grounds each year.
Limits are put on the number of fish that can be harvested and hatchery programs are scrutinized. Some fisheries have already been restricted due to the dry-summer conditions.
Pinks are not raised in hatcheries in Snohomish County. However, the harvest of some larger salmon in nearby waters, such as Tulalip Bay, are dependent on hatchery fish.
More money and resources are funneled into helping other salmon because they are listed under the Federal Endangered Species Act. Those conservation efforts also might be contributing to the success of the pinks, at least for now, Crewson said.
But, he fears that when the pinks start returning to the rivers to spawn in August and they encounter shallow, warm water from the dry summer, they’ll dogpile on top of other salmon in the few favorable spots.
All salmon are known to stay in the most desirable pools of water during poor conditions rather than spreading throughout the river. That behavior could lead to “a major die off,” Crewson said.
“Our rivers don’t have capacity to hold millions of pinks this year,” he said. “That should be a big concern for everybody.”
Lothrop, the Fish and Wildlife expert, also expects the drought to cause problems for the pinks. With less water to spawn in when they return to the river, there might be a decline in pinks returning in 2017, he said.
Small changes can result in big problems for pinks, Lothrop said.
“We’re looking good now but it’s up in the air in two years,” he said.
Crewson said more needs be done to help salmon. He believes the rules for habitat protections need to be improved, standardized and enforced by all of the responsible parties, such as city, county, state and federal agencies.
“We want to harmonize the regulations,” Crewson said. “When you fix a habitat, it makes fish every year. If you don’t, it kills them.”
The Tulalip Tribes, he said, hope to work with other agencies to come up with rules that benefit natural resources while also helping developers and businesses succeed.
Amy Nile: 425-339-3192; firstname.lastname@example.org.