Some of my fondest childhood memories are of fishing for sockeye salmon off the shores of Lake Washington. I’ve had the privilege of fishing in many locations throughout the Pacific Northwest, but there’s nothing like catching a salmon in the lake. It’s so cool to be out in the lake and see all the neighborhoods that you and your friends call home, and it’s even cooler to catch a salmon while doing it.
Lake Washington only has a sockeye season when at least 350,000 fish are forecast to enter the lake, but with seasons in 1996, 2000, 2002, 2004, and 2006, I had several marvelous summers of sockeye fishing. But since 453,543 sockeye returned to the lake in 2006, returns have dropped off precipitously, and there haven’t been any Lake Washington sockeye fisheries since. In fact, 2019 is forecast to see only 15,000 fish return – the lowest ever. The begs the question: why has Lake Washington’s sockeye run collapsed, and will it ever recover?
But since 453,543 sockeye returned to the lake in 2006, we’ve been lucky to see even 100,000 fish return. And 2019 is forecast to see only 15,000 fish return – the lowest ever. The begs the question: why has Lake Washington’s sockeye run collapsed, and will it ever recover?
As a kid who grew up fishing around Puget Sound, I can tell you that salmon are far harder to come by now than they used to be in the 90s or 00s. But as bad as things have been in Puget Sound, we’ve always had a salmon fishery of some sort. It’s been 13 years since the last Lake Washington sockeye fishery, and there are no signs that we’ll see one anytime soon. So why have Lake Washington sockeye in particular had such a tough time?
Sockeye: a history
Sockeye fry from the Baker River (a tributary of the Skagit River) were introduced into Lake Washington in 1935, one year after the Ship Canal was completed. These sockeye were primarily introduced into the Cedar River, which was formerly a tributary of the Duwamish but was diverted into Lake Washington in 1916 as part of the Lake Washington Ship Canal project. There may have been some small, natural runs through the Black River, which was the primary outlet from Lake Washington to Puget Sound until 1916 when the Ship Canal was opened and the lake dropped by 9 feet.
Retrieved from seattletimes.com
The introduction was an immediate success, with adult sockeye returning only four years after the initial plants. Hundreds of thousands of sockeye returned year after year to Lake Washington until runs decreased in the 90s, with the notable exception of a 500,000+ return during 1996. Runs recovered slightly in the early 2000s, but they’ve been pretty atrocious ever since the summer of 2006.
Experts believe that the biggest reasons for the decline of sockeye are predation of smolts by invasive species (most notably the Northern Pikeminnow and native Cutthroat Trout) and warmer-than-average river and lake temperatures. Predation has gotten worse in recent years as new invasive species such as pike and walleye establish themselves in the lake, and increasing light pollution makes it easier for cutthroat trout in particular to feast on these smolts at night. The fact that sockeye returns at the locks have continued to decline since a permanent hatchery on the Cedar River was built in 2011 suggests that many of these fish are not even making it to Puget Sound.
Warmer water temperatures due to the combination of hotter-than-average summers and below-average snowfall in recent years (particularly 2014-2015) weaken salmon and make them more susceptible to disease, particularly returning adults. According to Aaron Bosworth, the state district fisheries biologist, 45-85% of sockeye that went through the locks between 1995 and 2013 ended up in the Cedar River (which is responsible for 80-90% of Lake Washington’s sockeye run), but since 2014 only 20-33% have, and above-average temperatures and higher disease rates are almost certainly to blame.
What can we do?
In order to restore sockeye runs, we’ll need to focus on both decreasing predation of sockeye smolts in Lake Washington and ensuring that returning salmon are able to make it back up to their spawning grounds after passing the Ballard Locks. Both are daunting tasks – the amount of light pollution increases every year, new non-native predators such as walleye and pike are becoming more abundant, and temperatures will only rise in the coming decades. As much as I hate to admit it, trying to restore sockeye runs may be an exercise in futility, as Lake Washington’s ecosystem simply doesn’t support them anymore.
But given the importance of this fishery to Seattle, restoring the sockeye runs is worth looking into. The Cedar River Council had a meeting in April for just that purpose, featuring presentations by the Washington Department of Fish and Wildlife and Seattle Public Utilities on the likely reasons for the run’s collapse, what we’ll need to do to restore the run, and the role of the Cedar River hatchery. I hope that there will be further research into the feasibility of restoring the Lake Washington sockeye run, as it is – in my opinion – one of the best things that Lake Washington has to offer.
Sources:
https://www.seattletimes.com/life/outdoors/chances-dim-for-lake-washington-sockeye-fishery/
Featured image: watching salmon (in this case, Chinook salmon) migrate up the Ballard locks. Credit: King County / govlink.org
