Warm weather, low water wreak havoc on salmon
The exceptional summer heat hit the Snoqualmie River at a time when water flow was the lowest on record. The heat and low water levels combined to create a very challenging environment for the native salmon population.
“I truly mean the lowest lows ever recorded, and recording has been happening for many decades in that river system,” Snoqualmie Watershed Coordinator Janne Kaje said about the historically low water flow.
Over the summer, the water flow was extremely low. However, recent rain has helped spike the water flow to near normal levels again, although the yearly average is 10 percent to 20 percent below the norm for this time of year.
Kollin Higgins is a senior ecologist with King County who has spent a lot of time recently on conference calls with a variety of groups who are concerned about the water situation.
“They’ve definitely been nervous that this dry period is going to extend into November,” Higgins said. “It doesn’t sound very pretty from a water perspective.”
This time of year is when the adult salmon return upstream to their spawning grounds. But the heat and low water levels cause a number of issues for the fish.
“There’s just flat out less habitat for them,” Kaje said. “You get into situations where fish literally cannot get into some of the tributaries they would like to get into.”
The water level obstacles are compounded by the extreme heat of the river. Over the Fourth of July weekend, temperatures peaked at 79 degrees, well above the safe range for salmon.
“In the sort of salmon science, that is or can be acutely lethal,” Kaje said.
If the temperature doesn’t kill fish outright, it can have a range of negative effects, such as weight loss, slower growth and more disease. Furthermore, the problem can’t be easily measured due to the nature of salmon generations, which are produced about every four years.
“We won’t necessarily see how bad it is for another three to four years, when the adults return from this year and we get an idea of how much impact this has,” Higgins said.
Chinook salmon were already classified as a threatened species. These latest threats to their habitat only compound the problem.
“What is alarming about a year like this is that it’s consistent with what we think we’re going to see more of in the future,” Kaje said. “No single year or a single event can be said, ‘Well, that’s climate change.’ What worries me is that what we understand from the climate models is that this type of weather is likely to be more common.”
Kaje said that a higher frequency of warm weather could have a devastating effect on multiple generations of salmon.
“Bad years happen naturally,” he said. “I’m sure somewhere in history there has been a year like this in the Snoqualmie, not that we have recorded in the decades that we’ve been recording these things, but it’s the frequency that worries those of us that are working on this recovery.”
Higgins and Kaje said there are a number of things citizens can do to help, like put pressure on local governments to use water more efficiently, reduce personal water consumption for water-intensive landscaping like lawns, and plant trees along the banks of rivers and streams.
There are a number of organizations that can provide information and other resources for people who want to help like the Snoqualmie Tribe, Mountains to Sound Greenway Trust, Stewardship Partners, Sound Salmon Solutions and Wildfish Conservancy.
The precise amount of damage to salmon may not be measureable for a few years, but the damage is happening.
“We know that it’s not a good thing for fish,” Higgins said.
And with the frequency of warm weather projected to increase, the problems for the salmon may be getting worse before they get better.
“It feels a little bit like a race against time,” Kaje said.