A NextGen Blog by Lauren Rose, University of Exeter.
Photos © Alison M. Jones.
This NWNL NEXTGEN BLOG post focuses on salmon in the Columbia River Basin in the US-Canada Pacific Northwest. Since 2007, NWNL has supported watershed and hydrology education with internships and blog opportunities. Our NWNL NEXTGEN BLOG series hosts student essays; sponsors a forum for its high school senior, college and grad contributors; and invites proposals from new students to write on watershed values, threats and solutions. This article will be followed by another NextGen Blog post on the removal of the Lower Snake River Dams featuring a conservationist from the Columbia River Basin area.
Lauren graduated from the University of Exeter (UK) and University of Queensland (Australia) with a degree in Zoology. She is currently pursuing a Masters in Island Conservation and Biodiversity at the Jersey International Centre of Advanced Studies. She believes nature-based solutions best help our expanding human population live in harmony with the natural world. This post investigates the threats faced in freshwater habitats of Washington, Oregon and British Columbia by looking at their declining salmon populations due to dams.
Although 70% of the planet is comprised of water, only 1% holds accessible freshwater.[mfn]World Wildlife Fund[/mfn] Often overlooked, it is an essential resource, vital to every living thing on the planet. Freshwater ecosystems provide food for millions of people and form essential parts of food webs throughout the world. Approximately 10% of all wildlife, including 40% of the world’s fish population and a third of all vertebrate species reside in freshwater habitats.[mfn]Balian, E.V[/mfn] Globally, there are over 15,000 species of freshwater fish, 20% of which have become extinct or severely threatened in recent years.[mfn]Manel, S, et al.[/mfn],[mfn]National Geographic[/mfn]
Freshwater habitats and their wildlife are being damaged by human activities at a faster rate than terrestrial systems as our earth is currently undergoing a sixth mass extinction crisis. Our watersheds continue to be threatened by countless human activities including: pollution, dams, water diversion, agricultural runoff, urban expansion, overexploitation and climate change.[mfn]Manel, S, et al.[/mfn],[mfn]National Geographic[/mfn] Yet, freshwater systems and fish have immeasurable value in terms of human livelihoods, cultural, health and food-security.
The Columbia River Basin
In recent decades, the Columbia River Basin, one of the six NWNL watersheds, has greatly suffered from human activities. The basin stretches over 258,000km2, flows through seven states after flowing downstream from Canada. Around 6,500km2 of the Columbia’s waterways and lakes run through four mountain ranges, before draining into the Pacific Ocean.[mfn]Foundation for Water and Energy Education[/mfn],[mfn]American Rivers[/mfn] Previously, they harbored one of the largest salmon runs in the world, often exceeding 30 million fish a year. However, this is sadly no longer the case.Particularly, due to the development of hydroelectric dams, salmon populations, along with the overall water quality, has drastically declined.[mfn]American Rivers[/mfn]
The Columbia River’s unique geology and hydrologic cycle provided early settlers with a wealth of natural resources. The soils within the basin were fertile and there was an abundance of wildlife, in particular fish. Today, the basin is still incredibly valuable, but now its worth stems from its hydroelectric-power, flood control, irrigation and recreational opportunities.[mfn]Foundation for Water and Energy Education[/mfn] This shift in the exploitation of the Columbia River Basin has not only hindered local biodiversity, but also Indigenous tribes that have relied on the river’s resources for centuries.
Dam Development Destroying Biodiversity
Salmon used to occupy approximately 20,000km of the Columbia River Basin streams and rivers.[mfn]Columbia Basin Salmonids[/mfn] Before the 20th Century, an estimated 10 to 16 million adult salmon and steelhead trout returned to the Columbia River Basin annually. Today, only 2% of this number currently return.[mfn]The New York Times[/mfn] In 1950, almost 130,000 adult salmon returned to the Snake River to spawn, but by 2017, despite hatchery efforts, this figure had fallen below 10,000. All four species of Columbia River salmon and steelhead are now threatened with extinction, and as a result are threating the orca populations in the Pacific Ocean as they depend on salmon for their food.[mfn]The Natural Resources Defence Council[/mfn] There are multiple fisheries that depend on reliable populations of salmon, including those managed by the states of Washington, Oregon and Idaho – and, more significantly, many tribes that traditionally fished these waters.[mfn]National Oceanic and Atmospheric Administration[/mfn] Although exploitation, logging and farming have detrimentally impacted salmon populations, the single biggest impact was from construction of the Columbia and Snake River Dams.[mfn]The New York Times[/mfn] These hydro-dams have altered the natural flow of the rivers, preventing young salmon from reaching the ocean and adults from returning to upstream lakes and distant small streams to spawn.[mfn]
Due to their cyclic lifestyle, salmon are particularly vulnerable to the construction of dams. After several years in the ocean, adult fish return to the rivers in which they were born – which could entail an over 6000-mile swim upstream. Here, they spawn, die, and then their eggs hatch after 2 to 8 months. Gradually, they feed, grow and make their way downstream to join the ocean. They will then migrate thousands of miles out into the Pacific and grow into adults before returning to the rivers to spawn and continue their cycle.
Today, however, conflicts arise when small, juvenile fish try to pass down the river through dams, with 7 to 15% dying at each of these barriers. Dams also impact salmon survival by slowing the flow of rivers which increases the threat of predation and intensifies the effects of climate change on their habitat.[mfn]The Natural Resources Defense Council[/mfn] In 2015, warmed waters in the Columbia River Basin killed 250,000 sockeye salmon.8 Unfortunately, the reduction of a single species can have a cascading, effect throughout a food chain, thus degrading the environment and even impacting on human health.
Tribes Taking Action
There has been conflict between the biological damage dams cause and the economic benefits they provide. More often than not, the short-term and short-sighted economic benefits win. People have been quick to overlook the indirect benefits of biodiversity; however, today many groups are fighting for the removal Columbia River Basin dams. The Upper Columbia United Tribes recently congregated to address environmental and cultural issues threatening their communities and land. They are comprised of the Coeur d’Alene Tribe, Confederated Tribes of the Colville Reservation, Kalispel Tribe of Indians, Kootenai Tribe of Idaho and Spokane Tribe of Indians. Salmon previously comprised 80% of the diets of these tribes. Thus, declining salmon populations are not just a threat to biodiversity but also to food-security and cultural heritage.[mfn]The Natural Resources Defense Council[/mfn]
Until large-scale dam removals project can begin, temporary solutions should be put into place. For example, installing fish passages, using salmon cannons or increasing spill over dams enables more juvenile fish to migrate downstream. The Bonneville Power Administration originally resisted even these small compromises; however, some improvements have been made to make dams more eco-friendly. The U.S. Army Corps of Engineers has invested over $1.8 billion in fish passage improvements since 2001. Today, juvenile fish dam survival is estimated at 86 to 99% for dams in the Columbia River Basin.[mfn]Bonneville Power Administration[/mfn] Sirois, committee coordinator for the Upper Columbia United Tribes, says “Eventually those dams will come down… For now, we need to find ways to move fish.”
Fortunately, it is not all doom-and-gloom when it comes to a crisis such as this. There have in fact been success stories. Chinook salmon had been extinct from the Columbia’s Walla Walla River for over 80 years following the construction of the Nine Mile (Reese) Dam in 1905, which caused the river to run dry each summer for 100 years.[mfn]Columbia River Inter-Tribal Fish Commission[/mfn] Recognising the importance of Chinook salmon for culture, spirituality and ecological functioning, in 2000 the Umatilla Tribe began a reintroduction program to release surplus adult salmon upstream. In 2004 only 200 adult salmon returned, but in 2009 thisincreased to 1,135, with the ultimate goal being 5,500 adult fish. Thanks to this success, the tribe opened a fishery on the Walla Walla in 2010, for the first time in nearly a century.[mfn]Columbia River Inter-Tribal Fish Commission[/mfn] As populations continue to gradually increase, more than 2,000 adult salmon are expected to return to the Walla Walla River Basin by 2025.[mfn]Pollard, Jessica[/mfn] The Umatilla Tribe’s chinook reintroductions in the Walla Walla River shows how, when given the opportunity, adult fish stocks can recover from anthropogenic damage.
New and innovative engineering can provide mitigation methods to improve salmon stocks whilst not impeding the use of dams. We should ensure that more such decisions are made, considering long-term impacts and ensuring that consequences to biodiversity are effectively mitigated. By releasing more water from dams in spring, a healthier river flow can be reached, assisting salmon in their natural life cycles. We should work towards such sustainable, long-term, mutually beneficial solutions. The success of the Umatilla Tribe’s reintroduction of salmon to the Walla Walla River demonstrates that nature can recover. Humans have morphed, modified and exploited the natural world; but when given a chance, nature often can find a way – so let’s give her a chance.
American Rivers. Columbia River Washington, Orgeon, 15th May 2019. https://www.americanrivers.org/river/columbia-river.
Bonneville Power Administration. Columbia Basin salmon and steelhead: many routes to the ocean fact sheet, July 2013, available at https://www.bpa.gov/news/pubs/FactSheets/fs-201306-Columbia-Basin-salmon-and-steelhead-many-routes-to-the-ocean.pdf.
Columbia River Inter-Tribal Fish Commission. Columbia Basin Salmonids, 3rd November 2016. https://www.critfc.org/fish-and-watersheds/columbia-river-fish-species/columbia-river-salmon.
Foundation for Water and Energy Education. What Makes The Columbia River Basin Unique And How We Benefit, 18th September 2020, https://fwee.org/environment/what-makes-the-columbia-river-basin-unique-and-how-we-benefit.
Manel, S, et al. “Global determinants of freshwater and marine fish genetic diversity” Nature Communications. https://doi.org/10.1038/s41467-020-14409-7. 2020.
National Geographic. Freshwater Threats. National Geographic, 10th February 2021. https://www.nationalgeographic.com/environment/article/freshwater-threats.
National Oceanic and Atmospheric Administration. Columbia River Basin Salmon and Steelhead Fisheries, 16th October 2020. https://www.fisheries.noaa.gov/west-coast/sustainable-fisheries/columbia-river-basin-salmon-and-steelhead-fisheries.
The Natural Resources Defense Council. In the Columbia–Snake River Basin, Salmon Are Losing Their Way, 18th July 2018. https://www.nrdc.org/stories/columbia-snake-river-basin-salmon-are-losing-their-way.
The New York Times. How Long Before These Salmon Are Gone? ‘Maybe 20 Years’, 20th September 2019. https://www.nytimes.com/2019/09/16/science/chinook-salmon-columbia.html.
WWF. Water Scarcity. World Wildlife Fund, 11 February 2021. http://www.worldwildlife.org/threats/water-scarcity.Balian, E.V, et al. “The Freshwater Animal Diversity Assessment: an overview of the results.” Hydrobiologia, https://doi.org/10.1007/s10750-008-9302-7, 2008.