Sockeye salmon with lesions dying from hot water in the Columbia-Snake River Basin ©Conrad Gowell
I. INTRODUCTION
Welcome to the 2023 Hot Water Report: Warming Waters in the Lower Snake and Columbia Rivers.
During the summer, this weekly report provides an update on real-time water temperatures in the lower Snake and Columbia River reservoirs via graphs and analyses, a summary of the highest weekly water temperatures at the forebay/reservoir of each federal dam, and a monthly status of adult returns for different salmon and steelhead populations as they make their way back to their natal spawning grounds. We’ll report first-hand from scientists, Tribal members, fishing guides, advocates, and other experts about the challenges facing these rivers – and our opportunities to improve and restore them - in order to recover healthy, resilient fish populations and the benefits they deliver to Northwest communities, other fish and wildlife populations (including the critically endangered Southern Resident orca), and ecosystems.
Many once-abundant anadromous fish populations—fish that hatch in freshwater, go to sea, and return to freshwater to spawn—in the Columbia-Snake River Basin are on the brink of extinction today due primarily to harms caused by federal dams and their warming reservoirs. The Columbia-Snake federal hydro-system harms and kills both juvenile and adult fish in multiple ways, including by elevating water temperatures in the summer months in their large, stagnant reservoirs. These cold-water fish begin to suffer harmful effects when water temperatures exceed 68° Fahrenheit.
This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 71.64°F on August 12. On the lower Columbia River, the Bonneville and the John Day reservoirs registered the highest water temperature at 73.40°F, this week. Salmon and steelhead entering the lower Columbia River are now facing temperatures at 73°F—5 degrees above the 68°F “harm” threshold. For Issue 7, we have a special addition to the Hot Water Report - a series of articles about Southern Resident orcas and the urgency to restore the lower Snake River through dam removal to bring salmon back to abundance and significantly increase the amount of salmon available to the Southern Residents.
Restoring the lower Snake River by removing the four federal dams and replacing their services, is our only opportunity to recover and protect these once-highly prolific salmon and steelhead populations from extinction, uphold our nation's promises to Tribes, and help feed the critically endangered Southern Residents.
View the past Hot Water Report issues here: Hot Water Reports - Compiled
The Hot Water Report is a joint project of the Save Our wild Salmon Coalition, American Rivers, Association of Northwest Steelheaders, Columbia Riverkeeper, Earthjustice, Endangered Species Coalition, Environment Oregon, Idaho Conservation League, Idaho Rivers United, Natural Resources Defense Council, National Wildlife Federation, Northwest Sportfishing Industry Association, Orca Network, Sierra Club, Snake River Waterkeeper, Wild Orca and Wild Steelhead Coalition.
II. READING THE DATA - Water Temperatures in the Lower Snake and Columbia Rivers
Figure 1. Lower Snake River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.
Introduction to the data:
The daily average temperature at the four reservoir forebays (measured with sensors stationed at various depths below the reservoir surface, immediately upstream from the dam) in the lower Snake River (above) and the lower Columbia River (below) for 2023 is represented with solid lines and the 10-year average (2013 - 2023) temperatures with dashed lines of the same color. The dotted line across the graph represents the 68°F “harm threshold” for adult and juvenile fish.
The longer and the higher these temperatures rise above 68°F, the greater the harm, including: migration disruption, increased metabolism, increased susceptibility to disease, reduced reproductive potential (by reducing egg viability), suffocation (warm water carries less dissolved oxygen), and in the worst case - death.
Reservoirs are large, stagnant pools that absorb enormous amounts of solar radiation, and cause the water to warm. These waters inundate and destroy diverse micro-habitats that healthy rivers support, including cold-water refuges that salmon and steelhead rely upon during their migration. Without these vital pockets of cold water, salmonids cannot rest and recover on their journeys—adults moving upstream to spawn and juveniles moving downstream to the ocean. Rising temperatures and reductions in snowpack in recent decades due to climate change create warmer waters, which results in lower survival and reduced reproductive success for salmon and steelhead.
Figure 2. Lower Columbia River Water Temperatures - 2023 Daily Average and 10-year Average. Click on the image to view the graph.
Discussion of data:
Since April, temperatures in the lower Snake River and the lower Columbia River reservoirs have steadily increased. As Figure 1 shows, this week, the reservoir behind the Ice Harbor Dam had the highest average temperature of 71.40°F from August 12. The Lower Monumental reservoir had the second highest average temperature of 70.44°F on August 17.
As Figure 2 shows, this week, the reservoir behind the Bonneville dam registered the highest average temperature of 73.22°F on August 16 and 17. Both juvenile and adult salmon continue to experience water temperatures well above the 68°F “harm” threshold for over 40 days.
Below, we present the weekly high water temperatures for each reservoir on the lower Snake and Columbia rivers for August 9 - August 17.
A note on the data: The 2023 lower Snake River and lower Columbia River water temperature data presented in the Hot Water Report are collected from the Columbia River DART program by Columbia Basin Research, University of Washington, using data courtesy of the U.S. Army Corps of Engineers (USACE). The 10-year average water temperature data is courtesy of the Fish Passage Center. There is no data available for the Lower Monumental 10-year average water temperature, and McNary reservoir water temperature data is collected from USACE with current available data. Graphs and tables were assembled by SOS Staff.
III. WEEKLY HIGH WATER TEMPERATURES: August 9 - August 17
This week, on the lower Snake River, the reservoir behind the Ice Harbor Dam registered the highest water temperature at 71.64°F on August 12, and the Little Goose Dam registered the second highest temperature at 70.92°F on August 17. 
This week, on the lower Columbia River, the Bonneville reservoir registered the highest water temperature at 73.58°F.
IV. Critically endangered Southern Resident orcas need more Chinook salmon
K17 (large dorsal fin) with family at sunset ©Center for Whale Research
Highly social, highly intelligent Southern Resident orcas have roamed the coastal waters of the Pacific Northwest for hundreds of thousands of years. The three Southern Resident orca populations - the J, K, and L pods - have historically fed on an abundance of large, fatty Chinook salmon. However, today, Southern Residents face extinction due to the steep declines of Chinook salmon populations across the Pacific Northwest.
This week, we have a special addition to the Hot Water Report— a series of articles about Southern Resident orcas and the urgency to restore the lower Snake River through dam removal to bring salmon back to abundance and significantly increase the amount of salmon available to the Southern Residents, especially in the winter months when other salmon populations are far less available.
A. ‘Salmon and Orcas Are Being Managed Toward Extinction—and So Is the Lummi Nation’
J,K, and L pods returning to the Salish Sea in early June, 2008 ©Erin Heydenreich
“Like other members of the Lummi Nation, I am often out on these waters in the company of our ancestors and with our elders such as scha’enexw (“the salmon”), qwe’lhol mechen (“the killer whales”), and all our other relations in Xw’ullemy (the Salish Sea).
We call these other forms of life our elders because they are the ones who came first. We humans were the young and weak ones who could not survive without their generosity, their pity and compassion, and their spiritual strength. I sometimes wonder what qwe’lhol mechen would say if they could speak about their two-legged relatives on the land. I believe they would ask us if we know we are destroying their home and their way of life, and also starving their families and driving them to extinction. I believe they would ask why we have forgotten an inviolable and sacred obligation we made to them long ago.
We appeal, once again, to state and federal politicians to honor the spirit and intent of the treaties by breaching the Lower Snake River dams. We call on those officials to stand on the right side of history and on the moral high ground. They know and understand this is a matter of the survival of our lifeway and the spirit of our people.”
Read the full article here.
W’tot lhem (Jay Julius) is former Chairman of the Lummi Nation, a full-time fisher and father, and the Founder and President of Se’Se’Le.
B. Endangered orcas’ risk of inbreeding is increased by insufficient Chinook salmon and lack of positive government action to save both predator and prey.
By Wild Orca
L127 with mother, L94 | Taken under NMFS permit #26288 | Wild Orca.
Current Status
The total population of the Southern Residents now stands at 75, with the recent addition of two new calves. A male calf, L126, was born to Joy (L119), an eleven-year-old. Also, in L pod, a female calf, L127, was born to 28-year-old Calypso (L94).
This is welcome and good news. But while we celebrate these births that give us hope for the population, we must also keep in mind that the population, as a whole, is still struggling and urgent conservation actions are needed now more than ever. 11 of the Southern Residents are listed as vulnerable by Washington State Department of Fish and Wildlife (WDFW). Six of these whales remain on the list from last year. According to WDFW’s emergency rule, “the orca’s body condition falls in the lowest 20% of measurements for their age and sex compared to comparable measurements from 2016-2023.
Threats to recovery
Southern Residents are the original fishers of the PNW waters, co-evolving over millennia with their preferred prey, Chinook salmon. We know that almost half of the Southern Resident’s salmon originate in the Columbia River Basin. Before the lower Snake River dams were built in the 1960s and ‘70s, 40% of Chinook salmon began life in the Snake River Basin. Until roughly 100 years ago, Southern Resident orcas’ historical numbers ranged from 100 – 250 members. In this brief spate of time, colonizers arriving in the Pacific Northwest have drastically altered orcas and salmon’s habitat and population numbers by damming rivers, overfishing, deforestation, polluting waterways, and excessive, artificial noise such as marine vessels, aircraft, and other anthropogenic disturbances.
Another known threat that has recently been the subject of a 2023 study by NOAA is inbreeding. Southern Resident killer whales’ small population size puts them at risk of inbreeding. Coast-wide salmon declines initially caused a steep population decline in the Southern Residents, impacting their genetic diversity. In addition, it is now uncommon for true superpods to occur due to lack of salmon abundance. Simply put, there is not enough salmon to support the entire Southern Resident community in one place at one time. This decreases mating opportunities across the population and further impacts the gene pool. This risk is significantly increased by the lack of government action urgently needed to prevent the extinction of wild Chinook salmon. Well-fed whales would be less susceptible to disease and the impacts of environmental pollutants and vessels.
NOAA’s study, Inbreeding depression explains killer whale population dynamics, assesses how often inbreeding—mating with an animal with a common ancestor—occurs in the Southern Resident killer whale population. Scientists believe this leads to lower survival rates and population decline, known as “inbreeding depression.” Could this be a critical factor in their current struggle for survival, as NOAA now claims, or could their small population size and ill-health result from decades of inaction to restore wild Chinook salmon?
Is inbreeding the reason the SRKWs are not recovering?
Read the full article here.
C. Lasting Legacies of the Southern Resident orcas
J59 Sxwyeqόlh, female, born 2022 ©Cindy Hansen
The Southern Residents are one of the most studied and well-known populations of whales anywhere in the world. Thanks to pioneering research by Michael Bigg and Ken Balcomb, every orca in the population can be identified by unique markings and observed throughout their lives. Ongoing work by the Center for Whale Research provides known or estimated ages for each individual and an entire family tree dating back to 1976. We know who is a grandmother, an uncle, a cousin, or a friend. We know they share their prey with one another, even when times are hard and salmon is hard to come by. Because of this incredible body of work, people around the world have come to know and love these whales as individuals with unique personalities. During Orca Action Month every June, the Orca Salmon Alliance and their partners share stories so the public can get to know some legendary Southern Resident orcas who have left behind a ‘Lasting Legacy.’
Read more here.
People from all walks of life are united over their love and admiration for Southern Resident orcas, and no one wants to see them go extinct. If we want them to recover and thrive once again in the Pacific Northwest waters that have been their home for countless generations, we have to focus on recovering their prey.
One of the most essential components of a comprehensive range-wide recovery plan is restoring the Columbia-Snake River Chinook that are listed as a priority stock and make up the bulk of coastal diet for the Southern Residents. We need to immediately begin to replace the services provided by the Snake River dams, and begin breaching the dams as soon as possible. It doesn't have to be an us vs them situation - we can help recover endangered Snake River salmon, and in turn the Southern Resident orcas, while also ensuring our state continues to work toward alternatives for those whose livelihoods will be impacted by the breaching of the dams.
– Orca Network
