In the wake of floods, what’s next for salmon?

Recently released eggs likely bore the brunt of record-breaking rains in the Pacific Northwest.

 

Standing outside his house in Blanchard, Washington, water up to his thighs, Kevin Morse watched in awe as a few salmon — usually found in a nearby creek — swam across his driveway. His son spotted several more later that night while ferrying friends across the property in a canoe.

Morse is just one of thousands of people across western Washington and British Columbia who experienced severe flooding in mid-November. A potent atmospheric river storm — a long, narrow corridor of tropical water vapor that, when forced upward by obstacles like mountain ranges, condenses and sheds moisture — dumped massive amounts of rainfall, sometimes up to half an inch an hour, on the region. Bellingham, Washington, received more rain between Nov. 14 and 15 than it usually does in the entire month. Rivers like the Skagit and Nooksack spilled over their banks, and salmon, like the ones Morse saw on his driveway, were washed out of their streams. Mudslides wiped out roadways, and three out of every four homes in Sumas, Washington, were damaged by floodwaters. At least five people died.

As communities turn to cleanup efforts and brace themselves for yet more rain, experts say that the flooding could have both positive and negative ecological impacts on salmon. Salmon, a keystone species in the Pacific Northwest, are an important food source for 138 other species, including orcas. They’re also an essential component of regional tribes’ culture and sustenance, and they support an estimated 16,000 commercial and recreational fishing jobs.

Salmon already face numerous threats, including warmer waters caused by climate change, habitat loss, blocked migration routes and toxic stormwater runoff. Five species of salmon call Washington home: Sockeye, coho and chinook are locally endangered, while chum and pink are not. A 2020 report concluded that Washington’s salmon “remain on the brink of extinction.” It doesn’t help that this year’s already been rough for fish: A record-breaking heat wave in June caused widespread ecological fallout, and in September, warm water, low flows and bacteria killed thousands of endangered chinook before they could spawn in the South Fork Nooksack River. Treva Coe, a fisheries biologist and watershed restoration program manager for the Nooksack Indian Tribe, says the heavy rains could make salmon numbers dip further. “We do know from data on our populations that years with low survival are associated with years with high flows and large floods, so we’re really concerned that this year class survival is going to be low, if not wiped out,” said Coe.  

A few days after Morse saw salmon swimming down his driveway, they became food for eagles and raccoons. Salmon are anadromous, meaning they are born in rivers, spend most of their life in the ocean, and then return to freshwater to spawn before they die. Chinook, pink and sockeye salmon were spawning or had already spawned before the storm, meaning they were most likely the fish Morse saw, washed out of a channel and trapped in shallow water after reproducing. Their time was limited, anyway. But what about their descendants?

Salmon embryos are initially buried under gravel so they don’t float away. “They’re very vulnerable at that stage,” said George Pess, a watershed program manager at the National Oceanic and Atmospheric Administration’s (NOAA) Northwest Fisheries Science Center. “Floods could set the trajectory for this brood year.” Fish in the alevin stage are still growing and cannot move for a month or so, and even once they emerge as fry, they’re only 35 millimeters — a little longer than a quarter coin. Females can lay from 1,000 to 7,000 eggs, but depending how badly floodwaters churned up river bottoms, many of those eggs could have been unearthed from their hiding place, swept into the water column, and ended up as tasty treats for a variety of predators. 

“Floods could set the trajectory for this brood year.”

Flooded farmland near the Nooksack River in Ferndale, Washington.
James MacDonald/Bloomberg via Getty Images

“The key is whether the salmon were able to dig their nests deep enough not to be scoured,” said Thomas Quinn, a salmon researcher at the University of Washington. Egg nests, known as redds, could also be crushed by rocks and sand, or suffocated by silt as it settles. “In general, these floods are not good for them,” Quinn said. “I would expect the pink salmon will probably take a hit, and the chinook may take a hit from this.” But while he anticipates negative impacts, Quinn said, “I don’t think that they will be disastrous.” And species that have yet to spawn, like coho and chum, will probably be fine. 

A smolt trap on a lower portion of the Nooksack, designed to capture young fish as they migrate out to sea in the spring, will give the Nooksack Tribe its first indication of a population decrease. Similar traps exist on other rivers throughout the Puget Sound watershed. Four years from now — when this cohort of salmon has matured in the ocean and returns to spawn — the tribe will know whether there’s been a decline. George Swanaset Jr., the director of the tribe’s Natural and Cultural Resources Department, said tribal people have a duty to protect the salmon. Nooksack people, he said, have relied on salmon since the beginning of time. “We were fishermen, we lived with these fish,” Swanaset said. “Without salmon, we don’t exist anymore.” Swanaset and his co-workers are concerned that the tribe’s habitat restoration projects, including engineered log jams that create pools where salmon can conserve energy and find cool water during the summer, might have been damaged by the flooding. They’ll have a better idea once the floodwaters recede and remote travel is safe.

“We were fishermen, we lived with these fish. Without salmon, we don’t exist anymore.”

It’s not all bad news: Salmon have adapted to deal with periodic flooding, and the reshaping of the landscape could even create new habitat. High flows are essential for maintaining the complex river systems salmon need, and floods are a normal and necessary part of the ecosystem. “While folks might be really concerned about these flood impacts, it’s important to remember that floods have occurred for millennia, and they do provide some benefits to salmon, despite what it might look like at present,” said Bridget Moran, a conservation associate for American Rivers who focuses on Puget Sound and the Columbia Basin. To the south, atmospheric rivers have actually helped salmon get upstream during years of low flows and high temperatures by delivering essential water to watersheds. “We’ve seen a few different events come into the Pacific Coast, and it’s really been a godsend for California salmon,” said Nate Mantua, a fisheries and climate researcher with NOAA in Santa Cruz.

Unfortunately, human alterations to the landscape — damming rivers, draining floodplains for agriculture, constricting rivers to a single channel — have changed the way floods impact ecosystems and salmon, making floods more damaging than they would be naturally. And experts say climate change is accelerating the timeline for many of the challenges salmon face in the Northwest, from warmer waters to severe floods. Atmospheric rivers are predicted to grow longer, wider and wetter in a warming climate. It remains unclear how this will affect salmon resiliency. “We’re taking what they’ve more or less evolved for,” Quinn said. “And we’re pushing the envelope a bit.”

Kylie Mohr is an editorial intern for High Country News writing from Montana. Email her at [email protected] or submit a letter to the editorSee our letters to the editor policy.

 

High Country News Classifieds
  • CARDIGAN WELSH CORGIS
    10 adorable, healthy puppies for sale. 4 males and 6 females. DM and PRA clear. Excellent pedigree from champion lineage. One Red Brindle male. The...
  • A CHILDREN'S BOOK FOR THE CLIMATE CRISIS!!
    "Goodnight Fossil Fuels!" is a an engaging, beautiful, factual and somewhat silly picture book by a climate scientist and a climate artist, both based in...
  • DIGITAL ADVOCACY & MEMBERSHIP MANAGER
    The Digital Advocacy & Membership Manager will be responsible for creating and delivering compelling, engaging digital content to Guardians members, email activists, and social media...
  • DIGITAL OUTREACH COORDINATOR, ARIZONA
    Job Title: Digital Outreach Coordinator, Arizona Position Location: Phoenix or Tucson, AZ Status: Salaried Job ID Number: 52198 We are looking for you! We are...
  • DESCHUTES LAND TRUST VOLUNTEER PROGRAM MANAGER
    The Deschutes Land Trust is seeking an experienced Volunteer Program Manager to join its dedicated team! Deschutes Land Trust conserves and cares for the lands...
  • ASSOCIATE DIRECTOR OF DEVELOPMENT
    The Nature Conservancy in Wyoming seeks an experienced fundraiser to join our team. We're looking for a great communicator who is passionate about conservation and...
  • INDIAN COUNTRY FELLOWSHIP
    Western Leaders Network is accepting applications for its paid, part-time, 6-month fellowship. Mentorship, training, and engaging tribal leaders in advancing conservation initiatives and climate policy....
  • MULESHOE RANCH PRESERVE MANAGER
    The Muleshoe Ranch Preserve Manager develops, manages, and advances conservation programs, plans and methods for large-scale geographic areas. The Muleshoe Ranch Cooperative Management Area (MRCMA)...
  • ARTEMIS PROGRAM MANAGER
    Founded in 1936, the National Wildlife Federation (NWF or Federation) is America's largest and most trusted grassroots conservation organization with 52 state/territorial affiliates and more...
  • ASSISTANT OR ASSOCIATE PROFESSOR OF ENVIRONMENTAL HUMANITIES
    Assistant or Associate Professor of Environmental Humanities Whitman College The Environmental Humanities Program at Whitman College seeks candidates for a tenure-track position beginning August 2023...
  • ANNUAL FUND MANAGER
    Working closely with the Foundation's leadership, the Annual Fund Manager is responsible for the oversight and management of the Foundation's annual operating fund. This is...
  • DATABASE ADMINISTRATOR
    Looking for someone who loves public land and understands the value and importance of data in reaching shared goals as part of a high-functioning team....
  • EXECUTIVE DIRECTOR
    High Country Conservation Advocates (HCCA) in Crested Butte, CO is seeking an enthusiastic Executive Director who is passionate about the public lands, natural waters and...
  • ASSOCIATE DIRECTOR OF VOLUNTEER PROGRAMS
    Are you passionate about connecting people to the outdoors? The Pacific Crest Trail Association (PCTA) is looking for someone with volunteer management experience to join...
  • EXECUTIVE DIRECTOR
    The conservation non-profit Invasive Species Action Network seeks an executive director. We are focused on preventing the human-caused spread of invasive species by promoting voluntary...
  • NEW BOOK: A FEAST OF ECSTATIC VERSE AND IMAGERY
    Dynamic fine art photographer offers use of images to raise funds. Available for use by conservation groups. Contact at www.anecstaticgathering.com.
  • WANTED: TALENTED WRITER
    Write the introduction to A Feast of Ecstatic Verse and Imagery, a book concerning nature and spirituality. Contact at www.anecstaticgathering.com. Writer who works for conservation/nature...
  • MT STATE DIRECTOR- THE WILDERNESS SOCIETY
    The Montana State Director is a member of The Wilderness Society's (TWS) Conservation program team who plays a leading role in advancing the organization's mission...
  • HIGH COUNTRY NEWS EDITORIAL INTERNS
    High Country News, an award-winning magazine covering the communities and environment of the Western United States, is looking for its next cohort of editorial interns....
  • THE MAGICAL UNIVERSE OF THE ANCIENTS: A DESERT JOURNAL
    Bears Ears, Chaco Canyon, and other adventures in the Four Corners area. 60 photos and lively journals. Purchase hc $35 or pb $25 from bigwoodbooks.com...