Climate change

Tag: Climate change

Scientists look for answers in methane bubbles rising from bottom of Puget Sound

In 2011, sonar operators aboard the ocean-going Research Vessel Thomas G. Thompson inadvertently recorded a surprising natural phenomenon, as the 274-foot ship traversed through Puget Sound while returning to port at the University of Washington.
At the time, researchers on board were focused on a host of other projects. They might not have known that the ship’s multi-beam sonar was even turned on. They certainly didn’t realize that the sonar was picking up images that would later be interpreted as multiple plumes of methane bubbles rising from the bottom of Puget Sound.

Methane bubble plumes (yellow and white circles) are shown along the ship paths (purple). Black lines depict fault zones. Major sewer outfalls, shown as black squares, do not line up with the plumes so were ruled out as a source. (From article by Johnson et al, UW)

“Nobody looked at the data until about three years ago, when a former student of mine was working on a project looking at bubble plumes out on the Washington (Coast) margins,” said Paul Johnson, a UW professor of oceanography. “What she found was astonishing.”
The initial discovery of the methane plumes, by Susan Merle of Oregon State University, would lead to further discoveries of methane bubbles throughout most of Puget Sound. The findings have raised many interesting questions while providing implications related to the Puget Sound food web, studies of earthquake faults and even worldwide climate-change research. Johnson, Merle and other collaborators just published their first report on Puget Sound’s methane bubbles in the journal “Geochemistry, Geophysics, Geosystems.”
Nobody was even looking for plumes of bubbles in Puget Sound when Merle, a senior research assistant at OSU’s Cooperative Institute for Marine Resources Studies, began looking at eight-year-old archived sonar data from the RV Thompson. Following the ship’s tracklines, she observed the data as the sonar picked up images of methane bubble plumes along the coast. The sonar was still on when the ship entered Puget Sound. Merle kept following the data, not realizing that the surprising bubble plumes being revealed by the recorded sonar were all the way into Central Puget Sound, off Kingston on the Kitsap Peninsula.
“Nobody knew that there were methane bubble plumes there,” Johnson said after confirming her findings. “I said, ‘This is incredible. I wonder if there are other data out there to verify this.’”
The UW’s smaller 72-foot Research Vessel Rachel Carson operates with a less sophisticated single-beam sonar, but the ship travels all over Puget Sound, carrying student as well as professional researchers, generally on short trips. Like the RV Thompson, the RV Carson records sonar soundings wherever it goes, and those data records are kept on file.
Johnson retrieved the data from 35 cruises and found much more evidence of bubble plumes.
“There were these bubble plumes all over the place,” Johnson said, “so I said, ‘Let me have a day with the Carson,’ and we went up to Kingston in 2019.”
An instrument package was dropped to the bottom to pick up samples of water and gas around the plumes. “Sure enough, it was methane,” Johnson noted.
Thanks to a grant from the National Science Foundation for “speculative” research that might lead to breakthroughs, Johnson and his colleagues began to map bubble plumes throughout Puget Sound. They found bubbles from the Tacoma Narrows to Everett and also in Hood Canal, some 350 plumes in all.
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Besides Kingston, the deep water off Seattle’s Alki Point contained a surprising number of the plumes, which are described as clusters of holes in the sea bed through which the bubbles pass. Johnson said one can get a general idea of the effect by turning a kitchen colander upside down and submerging it in a sink full of water to see bubbles emerging through the holes.
By using remotely operated vehicles, the researchers can record video of the bubbles emerging out of sharp, well-defined holes, 3 to 5 inches in diameter and roughly 3 feet apart. More than a few holes appeared to be abandoned, not producing any bubbles. Others intermittently released a series of bubbles that rose to the surface.
“You can tell which are active because of bacteria mats,” Johnson said, explaining that the bubble plumes can be a rich feeding ground for methane-loving bacteria, which grow around the holes.
In mapping the bubble plumes, it became clear that large numbers were aligned along geologic fault zones, primarily the ones running east and west, known as the Seattle, Tacoma and South Whidbey faults. Others lined up with smaller north-south faults, but the greatest number of bubble plumes occurred where the faults intersected, such as off Alki Point in West Seattle.
Much of this phenomenon has yet to be explained, Johnson said. One idea is that the methane gas is largely confined beneath a layer of clay and compressed sediments laid down during the last glacial period. If so, the methane may be rising up through cracks in the confining layer, cracks created through tectonic activity.
Methane gas is produced naturally during the breakdown of organic compounds found in all living things. Biogenic methane is produced during digestion by certain types of bacteria. Thermogenic methane occurs at higher temperatures, especially under pressure. (See discussion in Science Direct.)
Because of the lower temperatures in Puget Sound, Johnson said he suspects that the methane is from biological processes. Off the Washington and Oregon coasts, both biogenic and thermogenic methane are being released from thousands of bubble plumes, with pronounced clusters in a north-south band some 30 miles off the coast. This region is along the tectonic boundary where the Juan de Fuca oceanic plate collides with the North American continental plate.
High temperatures and pressures in this subduction zone leads to the release of fluids and methane gas. The vast majority of plumes are seen on the seaward side of the continental shelf in waters about 500 feet deep. Faults in this region, created by powerful subduction earthquakes, appear to be the routes for methane gas and fluids to escape to the surface.
An early hypothesis suggested that the bubbles in Puget Sound might be coming up from this underlying subduction zone, but that has not panned out. The chemical signature of the methane in Puget Sound, as revealed through isotope analysis, does not match that from sources deep underground, where samples can be obtained from terrestrial hot springs and water wells.
Because the methane feeds bacteria at the base of the food web, bubble plumes off the coast have been found to flourish with biological activity, including large populations of krill and fish, Johnson said.
“Fishermen know where these areas are, because they are biological hotspots,” he said.
How this methane may affect the Puget Sound ecosystem is yet to be studied in detail, Johnson said. The answer may depend on the location and specific physical and chemical conditions. While the methane is likely to increase biological productivity, it may also play a role in the low-oxygen conditions that can affect sea life and create other problems.
Because the bubble plumes seem to be coming up through faults underlying Puget Sound, seismologists might be able to use them to locate unknown geological features, identify changes over time, or determine which faults are active.
These findings also are relevant to climate change, as scientists search to find other natural sources of methane. Since methane is a powerful greenhouse gas, climatologists are challenged to identify all natural as well as human-caused sources in order to predict the effects of reduced emissions. (See “Methane Budget,” Global Carbon Project.)
Globally, between 35 and 50 percent of methane emissions are believed to come from natural sources, including wetlands, according to the Environmental Protection Agency.
Methane’s lifetime in the atmosphere is much shorter than carbon dioxide, but methane is more efficient at trapping radiation. That’s why this gas raises major concerns. Pound for pound, the impact of methane is 25 times greater than carbon dioxide over a 100-year period, according to a report from the Intergovernmental Panel on Climate Change. In 2019, methane was said to account for about 10 percent of all U.S. greenhouse gas emissions from human activities.
The total amount of methane released from Puget Sound is relatively small when considering the total methane from many natural and human sources — including natural-gas leaks, raising livestock and garbage dumps. Still, Johnson hopes to launch a project that would estimate the total atmospheric emissions from the bubble plumes, while continuing to examine what is venting from all these holes. These new findings also point to ways to search for other natural methane sources around the world.
Related work by Shima Abadi, an associate professor at UW Bothell, involves analyzing the sound that the bubbles make and determining how that might relate to the amount of gas being released and other factors.
Other authors of the new paper are Tor Bjorklund, an engineer in UW oceanography; Chenyu (Fiona) Wang, a former UW undergraduate; Susan Hautala, a UW associate professor of oceanography; Jerry (Junzhe) Liu, a senior in oceanography; Tamara Baumberger, assistant professor at OSU; Nicholas D. Ward, affiliate assistant professor in UW Oceanography; and Sharon L. Walker of NOAA’s Pacific Marine Environmental Laboratory.

Plunging into a jungle of weather statistics to find the footprints of climate change

“Augusts in Seattle are getting hotter, leading to a change of 3.5°F since 1970.”
This was the sentence that caught my eye while reading an email from Peter Gerard, director of communications for Climate Central, an organization that prides itself on helping news reporters tell an accurate story of climate change.

Average temperatures for August at Sea-Tac airport, as analyzed by NOAA’s Applied Climate Information System, with enhanced graphics by Climate Central

I wondered immediately: Is there something special about the month of August? It turns out that there is, at least for Seattle and most areas around Puget Sound, but I needed to see the evidence for myself.
Thus began my journey down a rabbit hole of climate statistics in the Puget Sound region and across the state. I eventually dragged two experts — Washington State Climatologist Nick Bond and Climate Central meteorologist Sean Sublette — down into the hole to guide me. I found myself in a flood of data. These two experts showed me some clever tools to corral the numbers. And I finally emerged with a greater understanding of the pitfalls that climatologists must overcome to make sense of recorded temperatures as they try to forecast the future of climate change at the local level.
As Nick Bond stressed to me, temperature increases in one locale make up just a small piece of the overall climate-change picture. Most of the heat trapped in the changing atmosphere is absorbed into the ocean, he noted. Those oceanic conditions drive major shifts in weather patterns across the globe. Still, the increasing air temperatures that we measure locally can have a profound effect on plants and animals — including humans.
The heat wave of late June in the Northwest was a prime factor in the confirmed deaths of 100 people in Washington state — far above normal, according to the Washington State Department of Health. Heat may have contributed to the deaths of many others. Historically, June is an unlikely month to break all-time heat records, but climate change is altering a multitude of conditions and increasing the risks of perfect storms at unexpected times.
Because extreme heat can have devastating effects on humans and the natural ecosystem, I wanted to know how big this problem was in the past and how the trends are changing. While historical records have some problems, I learned that anyone interested could use tools readily available online to plot temperature trends and get an idea of how things are changing. I’ve added some footnotes along the way for those who would like to follow what I’ve been doing.
Starting point is critical
The first step in my journey through the numbers was to check the ongoing change in the average temperature for the month of August. But where does one begin? I quickly learned that when looking at trends, it makes a difference whether you start during a warm or cool period.
The same data from Sea-Tac as in the above graph but starting at 1973. // Source: Applied Climate Information System

For example, looking at Sea-Tac temperatures with a data-analysis tool by NOAA’s Applied Climate Information System, the trend from 1970 to 2021 is an increase of 3.4 degrees along a trend line that incorporates every average for August through 51 years. (See first graph at right.) 1
A trend line does not usually begin or end on the same temperature as the first or last data point in the series, but the starting and ending points can strongly influence the trend. For example, if one starts at 1973 (second graph), the change along the trend line to 2021 is 3.9 degrees.2 That’s a full 0.5 degrees higher than if one starts just three years earlier. The trend line becomes tipped by starting at 61.6 degrees for August 1973 instead of 64.5 degrees for August 1970 (along with the removal of three data points — 64.5, 67.7 and 66.7 for August 1970, 1971 and 1972, respectively).
One could say that the average temperature in August has gone up at Sea-Tac about 3.4 degrees since 1970 or 3.9 degrees since 1973. I also plotted the average of the maximum daily temperatures for August and found they had gone up by 4 degrees since 1970 (88° to 92°) or 5 degrees since 1973 (87° to 92°).3
Because heat extremes have an effect on health, one can also choose a temperature and see how many consecutive days reach that level, as in the graph at the top of this page. For example, I picked 90 degrees and asked how many times we saw that temperature at least two days in a row. From 1940 to 1981, the answer is 21 times.4 But from 1980 to 2021 — the same number of years — the answer is 43 times, about twice as often.5
You can pick any temperature and any length of “streak” for that temperature. Looking for at least three days of 85-degree heat, I found an occurrence of 27 times from 1980 to 2000 and 68 times from 2001 to 2021.6
What about a streak of at least 80 degrees for four days? The occurrence was 26 times from 2000 to 2010 and 63 times from 2011 to 2021.7 Even the changes in the last 10 years are significant with no cooling trend in sight.
Some people have noticed that the nights seem to be growing warmer, too. Plotting the average of the minimums, I found that the lowest temperatures in August have gone up at Sea-Tac by 4 degrees (49° to 53°) since 1973, slightly less for 1970.8
August normally cooks
Why the focus on August? It turns out that for much of the Puget Sound region, August is not only the hottest month of the year on average, but it is also the month in which the temperatures have been rising faster, year to year, than any other month.
While these numbers and the resulting trends may be revealing and are a good place to start, their value is limited by the time scale, starting and end points, and choice of a single location (Sea-Tac).
“It gets complicated, and the potential for cherry-picking is really high,” Nick told me. “You have to really guard against that.”
The goal is to dig into the numbers to understand what is happening, he said, not to support anyone’s convictions. Climatologists have spent considerable time trying to confirm historical temperature records and clear out discrepancies.
Across the country, it is easier to obtain complete and consistent data since 1970, according to Sean Sublette, explaining why Climate Central often uses that time period as a reference. But, as Sean points out, one may get a better idea of a long-term trend by considering a longer time scale. Since Sea-Tac data go back to 1945, we can see that the change in average August temperature from 1945 to 2021 is 5.3 degrees along the trend line. 9
For the sake of comparison, that’s 0.70 degrees per decade if you start from 1945, 0.67 starting at 1970, and 0.81 starting at 1973. So if one wanted to cherry-pick the data for a more extreme temperature rise, the starting year would be 1973.
Despite these differences, it is clear that the temperature is going up at Sea-Tac in a very significant way, no matter when one starts the graph. While I’m just fumbling with local numbers in relatively recent history, climate experts have made a compelling case for climate change by looking back thousands of years. (NASA: “How do we know?”)
Taking a look around
With Sea-Tac findings in hand, I began to look at other locations, using a helpful trend-analysis tool on the webpage of the State Office of Climatology. This data set, which goes back to the 1800s, uses temperatures adjusted for observed biases and inconsistencies, with the most reliable data usually coming in recent years.
Trend analysis tool for temperature, precipitation and snow water equivalent found on the website of the Washington State Climatologist. (Click to access.)

By choosing a starting year and selecting a trend range, one can simply move the curser across the map from one location to another and compare the differences. For example, with 1970 as the starting year and a time frame of August, I found a fairly wide range of temperature increases — up to 4.85 degrees in Vancouver in Southwest Washington.
According to Nick, some of the differences may relate to changing conditions around the monitoring stations themselves. Since concrete and hard structures absorb more heat, urbanization can result in a more rapid rise in temperatures than in surrounding rural areas, particularly forested areas. This is known as the “heat island effect.”
Some observers speculate that construction of a third runway at Sea-Tac Airport along with growth in surrounding residential and commercial areas may be responsible for higher temperatures at the Sea-Tac weather station than would have been recorded without that growth.
In any case, by comparing average temperatures from June through September at various locations, it appears that August temperatures are going up the fastest in most areas across the state — although for some stations July is changing nearly as fast or even faster than August. In some areas of Eastern Washington, September temperatures appear to be going up faster than July or August, based on these single-location numbers.
Why August would be growing warmer faster than other months is not easy to explain. One idea is that the ground is becoming drier over time near the end of summer because of our increasing temperatures. Drier conditions mean less evaporation and less transpiration from the leaves of plants. Since the processes of evaporation and transpiration lead to cooling effects at the source, less moisture may mean less cooling to offset the warming of the sun. Still, the variation in weather conditions — including precipitation — makes any specific cause difficult to prove.
Changing the scale
I like the map on the state climatology website because of its simplicity, but Nick advises not to draw broad conclusions from individual locations. Another useful analytical tool, Climate at a Glance, offers a variety of temperature sources. One can look at data for a city, county, state or region or take national or global perspectives using this webpage from NOAA’s National Centers for Environmental Information.
In recent years, annual average temperatures nearly always exceed the long-term average since 1901. Graph: Climate at a Glance, NOAA National Centers for Environmental Education

For the Puget Sound lowlands, go to “divisional” and “time series,” and pull down Washington state to pick a region. Since 1945, the average temperature across the Sound for August has gone up 0.5 degrees per decade, as shown in the upper right corner.10 Since 1970, the trend is 0.6 degrees per decade, 11 but it reaches 0.7 degrees with a starting point of 1973.12 This average increase in August temperatures in the Puget Sound region appears to be higher than for most other regions of the state.13
Another interesting way to look at the rising temperatures around Puget Sound is to compare monthly temperatures to a long-term average. For example, the average August temperature from 1901 to 2021 was 63.1 degrees, as shown by the “base period” in Climate at a Glance. 14
From 1901 to 1940, 57 percent of the August averages fell below the long-term average, as shown in the “departure” table below the graph.15 From 1941 to 1980, 52 percent were below the long-term average.16 But from 1981 to 2021, a similar period of time, only 2.4 percent were below the long-term average.17 In fact, over the past 20 years, only one August (2007) fell below the long-term average, and it was just 0.1 degree lower at 63.0 degrees. This is just another way of saying that temperatures have gone up to a remarkable extent over the past 20 years.
When looking at averages for the entire year, not just the month of August, the result is similar but less dramatic. Only six times in the past 41 years did the average annual temperature for Puget Sound fall below the overall 1901-2021 average.18 And that happened only twice in the past 20 years, with the last time coming a full decade ago.19
Heating in waves
Fall weather seems to be setting in even more now, and memories of the summer heat wave in June may be fading, despite long-term damage to the ecosystem from drought, wildfires and over-heated beaches (Our Water Ways, July 13).
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For people living in the Northwest, June’s heat wave was like nothing ever seen before. Visits to hospital emergency departments because of heat-related illness were 69 times higher than the same period of June 25-30 in 2019, according to a report from the Centers for Disease Control and Prevention. More than 1,000 heat-related illnesses occurred in Washington, Oregon and Idaho on June 28, when Portland reached 116 degrees and records were shattered throughout the region.
Extreme heat events are predicted to occur more often and last longer, according to Dr. Scott Lindquist, Washington’s acting state health officer, stressing that climate change is a major public-health threat as well as an environmental challenge.
“This huge jump in mortality due to heat is tragic and something many people thought they’d never see in the Pacific Northwest with its mostly moderate climate,” Lindquist said in a news release from the Department of Health. “But climates are changing, and we see the evidence of that with dramatic weather events, major flooding, historic forest fires, and more.”
People over the age of 60 have been shown to be especially vulnerable to heat waves, according to a report in the Canadian Medical Association Journal. Increased illness and the use of more medications among seniors can increase the risk of serious problems, but older people also appear to have less ability to sense heat and respond appropriately, the report says.
For more on heat-related illness, read the CDC report (PDF 676 kb) on the subject.
I had plunged into this jungle of weather statistics to see if I could learn something about climate change at the local level. Did I really need to be convinced that we are living in a world that is growing dramatically warmer? Probably not, but now I have a wider perspective when reading the findings of the Intergovernmental Panel on Climate Change, including “Climate Change 2021 — The Physical Science Basis” as well as new reports scheduled to be released next year.
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FOOTNOTES with details of the analytical tools
1 SC ACIS Product selection: Single-station products, Seasonal time series. Options section: Average temp, 1970-2021, month: Aug, ✔Include regression line. Station/area selection: Seattle; click search, click on map for Sea-Tac, GO.
2 Same as footnote 1, with 1973-2021.
3 Same as footnotes 1 and 2 with Options section: Max temp.
4 SC ACIS Product selection: Single-station products, Consecutive days. Options section: 1940-1981, Criteria: Max temp >= 90, All runs >= 2 days. ✔Include start date with results. Station/area selection: Seattle, click search, click on map for Sea-Tac, GO.(The results can be ordered by clicking on the column header.)
5 Same as footnote 4 with 1980-2021
6 Same as footnotes 4 and 5, with Max temp >= 85, All runs >= 3 days.
7 Same as footnotes 4 and 5, with Max temp >= 80, All runs >= 4 days.
8 Same as footnotes 1 and 2 with Options section: Min temp.
9 Same as footnote 1, with 1945-2021.
10 Climate at a Glance Click on divisional, time series: ✔display trend, per decade, Start 1945, End 2021. Average temperature, 1-month, August, Start year 1945, End year 2021. State: Washington, Climate Division: 3. Puget Sound lowlands. Plot.
11 Same as footnote 10 with Start year 1970 for trend and plot inputs.
12 Same as footnote 10 with Start year 1973 for trend and plot inputs.
13 Same as footnotes 10, 11 and 12 with change in Climate Division input to selected options.
14 Same as footnote 10 with ✔Display base period: Start 1901, End 2021.
15 Same as footnote 14 with Start 1901 and End 1940 for trend and plot inputs. Sort “Departure from Mean” by clicking on the column head. Negative numbers are below the average.
16 Same as footnote 15 with Start 1941 and End 1980 for trend and plot inputs.
17 Same as footnote 15 with Start 1981 and End 2021 for trend and plot inputs.
18 Same as footnote 15, with Time Scale: annual and Start 1981 and End 2021.
19 Same as footnote 15, with Time Scale: annual and Start 2001 and End 2021.

Can biologists estimate the massive loss of shellfish caused by low tides, high temps?

The putrid smell of rotting shellfish on some beaches in Puget Sound and elsewhere along the West Coast were a clear sign that large numbers of clams, mussels, oysters and other intertidal creatures were killed from exposure to extreme low tides, record-breaking temperatures and a blazing hot sun.
The total losses of shellfish that perished late last month may be difficult to estimate, but experts are beginning to piece together evidence from shoreline residents, state and tribal biologists, and commercial shellfish growers. Their goal is to describe what took place during the record-breaking temperatures of June 25-29 during some of the lowest tides of the past century.

The recent heatwave killed large numbers of shellfish throughout Puget Sound, including these butter clams in Quartermaster Harbor, Vashon Island. // Photo: Ron Carr

Understanding what happened during that June event might help avoid future shellfish disasters as the climate continues to change with no end in sight, officials say.
“We’ve been getting reports from Puget Sound to Canada, including the outer coast,” said Teri King, a shellfish biologist with Washington Sea Grant. “The effects of the heatwave were not uniform. Some areas got hammered and some seemed to escape (the problems).”
Tori Dulemba, who lives on the North Shore of Hood Canal near Tahuya, owns a south-facing beach with a gradual slope. Those conditions led to a long period of exposure to the hot sun when afternoon tides were the lowest since 2008 and when temperatures soared well above 100 degrees.
“You could easily smell the rotting shellfish,” Tori told me. “We knew immediately what it was. The oysters were cooked. The mussels were still attached, but the shells were empty. It was heart-breaking.”
The odor, she said, was much like the smell of dead salmon in areas where large numbers of fish still return to spawn and die in the streams. After a few days, the smell of dead shellfish dissipated, and it was gone after a week or so, but empty shells remained.
Teri King, who coordinates the Bivalves for Clean Water citizen education and monitoring program, said the first reports she received included descriptions of stressed clams digging themselves out of the ground and opening up on the surface of various beaches.
Based on reports, it seems that sand dollars were the first to succumb, followed by cockles, varnish clams, mussels, littleneck clams and butter clams, she said. There were also reports of dead Olympia oysters and Pacific oysters. Even barnacles turned up dead, while some sea stars and anemones also were killed.
A large number of the big moon snails common to Puget Sound got so hot that they literally uncurled themselves and came out of their shells, lying like balls on the beach, Teri said.
During the recent heatwave, tide levels were among the lowest in the past century. At Union on Hood Canal, shown here, the level was estimated to be at -4.37 feet at noon on June 25. Click to visit NOAA’s website for more specific data. // NOAA Tide Predictions

It seems that some areas were more sheltered from the sun or less affected by low tides because of the slopes of the beaches or the direction they faced. In general, problems were worse in South Puget Sound than in the north, Teri said, probably because the tides are more pronounced the farther south you go, leaving shellfish exposed for longer periods of time.
Teri and other officials are still taking observations and photographs from shoreline observers who were able to note the effects on shellfish caused by the extreme and extended heat. The Washington Department of Fish and Wildlife has provided an online form for observers to fill out, or they can send their information by Email.
Camille Speck, intertidal shellfish manager for WDFW, confirms the hit-and-miss nature of the massive shellfish die-off. While some public beaches were affected, others seem to have gotten by with minimal effects.
“What we saw at Dosewallips was very heartening,” Camille told me. “One-year-old or two-year-old oysters seemed to be doing just fine.”
She was speaking of Dosewallips State Park, a popular beach open to the public for shellfish harvesting. The beach lies on the western shoreline of Hood Canal, which may be better sheltered from the heatwave than the eastern shore or the northern shore around the “bend”.
Camille has yet to survey a number of public beaches, so she can’t say whether recreational shellfish seasons might need to be shortened to ensure future production. In some cases, quotas may be adjusted next year to compensate for losses, depending on the number of recreational harvesters and the amount of shellfish taken the rest of this year.
Photo: Ron Carr, Quartermaster Harbor

It was like a “perfect storm,” having such extreme low tides occurring coincidentally during the record-breaking heat, Camille said. Only two tidal periods in the last 100 years — one in 2008 and the other in 1916 — were lower, she said, and the temperatures climbed to levels never seen before in many places.
In Seattle, for example, the city had experienced 100-degree temperatures only three times in the past 126 years before they reached that level three days in a row, breaking the all-time record with 104 degrees on June 27 and again the next day with 108 degrees.
Meanwhile, some commercial shellfish growers have been gathering information to record their losses and possibly receive disaster relief from the federal government. Recent revisions to a federal program called Emergency Assistance for Livestock, Honey Bees and Farm-raised Fish (ELAP) may provide compensation for growers who can document their losses to the U.S. Department of Agriculture, officials say. For information, contact your county office of the Farm Service Agency.
A major hurdle in coming up with an estimate of actual losses — for commercial or noncommercial shellfish beds — is knowing what shellfish were present before the heatwave killed a portion of the shellfish.
Margaret Pilaro, executive director of Pacific Coast Shellfish Growers Association, said it is her understanding that growers must notify the USDA of potential losses within 30 days of the event. She has been trying to notify all of Washington’s certified shellfish growers of the possibility for financial aid to make sure that they don’t miss the deadline.
Tribal biologists also are out surveying the shellfish die-off, especially in areas where tribes have plans to harvest shellfish, as allowed by treaty. For state and private lands not cultivated for shellfish, the tribes are entitled to half the harvestable amount.
Biologists hope that a rough estimate of the total damage caused by the heat and low tides can be achievable, although such an estimate will be complicated by the patchy nature of the losses as well as the uncertainty about what was present in some areas before the event. For now, the main focus is to gather information from as many beaches as possible throughout Puget Sound.

In the topsy turvy world of climate change, Western Canada to the north experienced a similar but even more punishing heatwave, according to Tom Di Liberto, a meteorologist with CollabraLink Technologies. He says Lytton, British Columbia, reached 116 degrees on June 27, breaking the all-time record for all of Canada. But the oppressive weather was not over, as the temperature rose to 118 degrees the next day and then to 121 degrees on June 29. That is hotter than the desert town of Las Vegas, Nev., has experienced since records were first kept, according to Tom.
Likewise, the shellfish in British Columbia were reported to be cooking on the beach, perhaps even worse than in Puget Sound, as reported by Canadian news outlets.
Chris Harley, a marine biologist at the University of British Columbia, threw out an estimate of a billion shoreline creatures perishing in the Salish Sea as a result of the heat. That number, reported by Alex Migdal of CBC News, was crudely calculated by expanding the findings from a small area. The number subsequently raised a lot of eyebrows among experts on both sides of the border — but who could dispute it?
Commenting on the estimate, Chris Neufeld of Bamfield Marine Sciences Centre on Vancouver Island, said he was not surprised, adding, “It was very disheartening to realize we’re actually in this moment that we’ve been predicting for a long time.”

Issaquah Creek. Photo courtesy of Nicholas Georgiadis.

Are summer low flows increasing in Puget Sound streams?

Update: A pdf of slides from the presentation is now available.
Adequate stream flows are critical to Puget Sound’s endangered salmon and are one of the state’s ‘Vital Sign’ indicators of ecosystem health. Earlier data suggests that summer stream flows have been on the decline, but new analysis shows that gauging these flows may be more complicated than previously thought. On Monday, March 15th, Puget Sound Institute senior research scientist Nick Georgiadis will discuss statistical models that show an apparent increase in summer stream flows over the past 20 years due to climate oscillations. His talk will be presented at 10:00 AM via Zoom at the link below.
Join the Zoom meeting: https://washington.zoom.us/j/96431547752
Date: March 15, 2021
Time: 10:00 AM (Please login at 9.55 AM)
Meeting ID: 964 3154 7752
Program abstract:
For streams flowing into Puget Sound, the lowest flows of the year (‘summer low flows’) must be sufficient to sustain instream biota, including salmon, for the foreseeable future. Evidence that low flows have declined raised concerns that factors relating to human development, including anthropogenic warming (globally) and groundwater abstraction (locally), may have impacted low flows, and will further impact low flows in the future. Uncertainty about causality requires that a precautionary approach be adopted in restoration and preservation strategies currently under development. To better inform these strategies, much remains to be learned about factors affecting low flows. I will present statistical modeling results suggesting that opposing, multi-decadal oscillations in rainfall and temperature drive a pronounced oscillation in low flows. The declining phase of this oscillation in low flows spans ~1960-2000. Since then, trends in low flows appear to have switched from negative to positive. These patterns characterize how climate change and variation have affected low flows in the past, and help to shape our expectations for the future.

A look at future ocean conditions and how they could affect coastal communities

Scientists tell us that climate change is probably increasing the frequency of extreme events, such as hurricanes, droughts and wildfires. As time goes on, we might expect even more dramatic shifts in the ecosystem, as some species move to more suitable locations and others die out.
The Pacific Fishery Management Council, which oversees fishing along the West Coast, has launched an effort to become more nimble and responsive to changing conditions with regard to estimating fish populations and approving sport and commercial fisheries.

The future of West Coast fish stocks could be determined by human decisions. // Image: Center for Environmental Visualization and Robert Francis, School of Aquatic and Fishery Sciences, University of Washington

One effort is to describe how the ecosystem could change over the next 20 years and how those changes could affect coastal communities dependent on fishing. A new document titled “Scenarios for West Coast Fisheries – 2040” (PDF 1.4 mb) was recently released in draft form and will be the subject of discussions during next week’s meeting of the fishery council.
“The general idea of scenario planning is to develop descriptions of alternative plausible futures,” said Kit Dahl, staff officer who is leading the effort for the fishery council. “It’s not a prediction per se but a way of describing what we know with imagination as we look to what the future might hold.”
As Kit explained it, four scenarios were developed to represent the full range of future conditions that might be experienced. More than 80 experts participated in a series of six workshops during May and June to scope out the scenarios, based upon two fundamental uncertainties:

  1. Will the effects of climate change — including temperature and ocean acidification — come on gradually with infrequent surprises, or will we see extreme variability with ecological upheavals and uncertain weather conditions?
  2. Will ecological changes result in an increase or a decrease in fish stocks commonly harvested along the West Coast?

The four separate scenarios were developed and given interesting names. The discussion in the report, which includes future prospects for marine mammals, fish stocks and human communities, opened my eyes to a number of possibilities. Here’s just a sampling from the four scenarios:
Fortune and Favor: Gradual changes, good fish stocks
Under this most-favorable scenario, climate change is not as extreme as predicted in 2020. Fish stocks are gradually moving north to maintain favorable temperatures.
As the U.S. comes out of the COVID-19 pandemic, cyber conflicts grow more intense. The fishing industry becomes less international with broad-scale efforts to promote domestically produced seafood.
A younger generation takes a long-term, ecosystem-based perspective that includes removing dams, restoring wetlands and recovering endangered species. Serious efforts to reduce greenhouse gases began in the 2030s. By 2040, the U.S. economy is on a firm path to a carbon-free future.
Coastal communities re-embrace fishing identities, as community-based fishing, processing and marketing takes hold with new technologies. Changing attitudes and advanced technologies, such as carbon-neutral propulsion, leads to a rebirth in sport fishing.
An ecosystem-based approach constrains catch for individual fisheries, which frustrates fishermen, but the overall catch increases. Technological innovations and institutional changes offer hope for solutions.
A Blue Revolution: Gradual change, but fish decline
A warming climate and ocean causes familiar fish stocks to decline, but subtropical and tropical fish find favorable conditions along the West Coast. A more open, global economy seeks inexpensive ways to supply protein, and wild-caught fish struggle under the pressure.
Throughout the 2030s, public sentiment has increased to address carbon emissions, leading to offshore energy supplies based on wind, currents and thermal properties of ocean water. Public values move away from animal protein to seafood and plant-based proteins.
Aquaculture puts competitive pressure on large-scale commercial fisheries, but coastal communities maintain some of their character with the help of federal investments in infrastructure — including rural broadband that supports remote office work. Recreational fishing sees a resurgence but with lower catch limits.
Increasing aquaculture creates conflicts with the commercial fishing industry, and fishery management councils take on new roles in regulating offshore aquaculture.
Harmful algal blooms increase in frequency; the ecosystem becomes less productive; and marine mammal populations decline. While wild salmon have less pressure from predators, lower ocean productivity reduces their numbers. Improved hatchery practices allow for continued salmon production.
Box of Chocolates: High climate variability, good fish stocks
In this scenario, we view “a world of environmental surprises and extremes, but where stock levels increase on average” with fishermen seeing “regular boom-and-bust cycles for some key stocks.”
Species rarely seen in the Northern Hemisphere show up suddenly, allowing for harvestable levels of unusual fish. New technology becomes the key to keeping up with less predictable conditions and allowing the exploitation of available fish. Seafood marketing becomes more difficult due to the high variability in seafood supplies, but consumers seek wild-caught fish for health and emotional reasons.
In some areas, salmon fishing may be good at times, but sport fishermen cannot depend on catching fish at their old reliable fishing spots.
Snowpack melts early except in the highest elevations. California enters a prolonged period of drought, which contributes to the extinction of many wild salmon stocks.
Dams on the Klamath and Snake rivers are removed, improving prospects for wild stocks. Widespread development of alternative energy supplies continues to fuel the debate about removing dams on the mainstem of the Columbia River, but the need for water storage blunts the argument as droughts become more frequent.
Hollowed Out: High climate variability, and fish decline
Unpredictable and extreme shifts in ocean conditions upsets the traditional food web along the West Coast. Only a few stocks of fish remain at harvestable levels, and commercial fisheries practically disappear except for highly specialized commodity fisheries and part-time operations. Wild-caught fish have become a high-priced delicacy.
Recreational fishing exists but continues on its long decline. Some rural fishing communities are abandoned. Others become focused on shipping, tourism or urban waterfront homes. Because of persistent, damaging storms, waterfront communities are fortified against unprecedented waves.
Economic downturns, climate change and marine pollution become more worrisome around the globe. In many ways, the market for seafood never recovers from the economic shocks of the 2020s. People worry about species extinction and ecosystem services, putting more emphasis on protecting species and producing alternative protein sources like algae, hemp and laboratory-grown “meat.”
Even aquaculture struggles to survive, as coastal areas are seen as too polluted to produce healthy foods, and struggling facilities are battered by high winds and waves. Some land-based, closed-system aquaculture facilities provide fish to a high-end market.
Salmon are devastated by the conditions. Even with a decline in marine mammals, the combination of poor freshwater conditions and poor ocean productivity have driven many salmon stocks to extinction, while others struggle to survive.
Next steps
While these scenarios can help us visualize four different options for the future, it is important to understand that the visualizations are only as good as the assumptions that go into them. We are dealing with a multitude of both natural functions and human actions, some of which can literally change the ecosystem as well as the society in which we live.
Some things are beyond human control, but a first step toward achieving a desirable future is understanding what we can control. After that, we can go about taking actions to set the stage for the world in which our great-great-grandchildren will live.
Anyone interested in these scenarios may submit comments to the Pacific Fishery Management Council. The next step will be to identify specific challenges to particular communities, regions and people involved in the fishing industry. From those discussions will come proposed actions that could help people prepare for a better future.

A look at future ocean conditions and how they could affect coastal communities

Scientists tell us that climate change is probably increasing the frequency of extreme events, such as hurricanes, droughts and wildfires. As time goes on, we might expect even more dramatic shifts in the ecosystem, as some species move to more suitable locations and others die out.
The Pacific Fishery Management Council, which oversees fishing along the West Coast, has launched an effort to become more nimble and responsive to changing conditions with regard to estimating fish populations and approving sport and commercial fisheries.

The future of West Coast fish stocks could be determined by human decisions. // Image: Center for Environmental Visualization and Robert Francis, School of Aquatic and Fishery Sciences, University of Washington

One effort is to describe how the ecosystem could change over the next 20 years and how those changes could affect coastal communities dependent on fishing. A new document titled “Scenarios for West Coast Fisheries – 2040” (PDF 1.4 mb) was recently released in draft form and will be the subject of discussions during next week’s meeting of the fishery council.
“The general idea of scenario planning is to develop descriptions of alternative plausible futures,” said Kit Dahl, staff officer who is leading the effort for the fishery council. “It’s not a prediction per se but a way of describing what we know with imagination as we look to what the future might hold.”
As Kit explained it, four scenarios were developed to represent the full range of future conditions that might be experienced. More than 80 experts participated in a series of six workshops during May and June to scope out the scenarios, based upon two fundamental uncertainties:

  1. Will the effects of climate change — including temperature and ocean acidification — come on gradually with infrequent surprises, or will we see extreme variability with ecological upheavals and uncertain weather conditions?
  2. Will ecological changes result in an increase or a decrease in fish stocks commonly harvested along the West Coast?

The four separate scenarios were developed and given interesting names. The discussion in the report, which includes future prospects for marine mammals, fish stocks and human communities, opened my eyes to a number of possibilities. Here’s just a sampling from the four scenarios:
Fortune and Favor: Gradual changes, good fish stocks
Under this most-favorable scenario, climate change is not as extreme as predicted in 2020. Fish stocks are gradually moving north to maintain favorable temperatures.
As the U.S. comes out of the COVID-19 pandemic, cyber conflicts grow more intense. The fishing industry becomes less international with broad-scale efforts to promote domestically produced seafood.
A younger generation takes a long-term, ecosystem-based perspective that includes removing dams, restoring wetlands and recovering endangered species. Serious efforts to reduce greenhouse gases began in the 2030s. By 2040, the U.S. economy is on a firm path to a carbon-free future.
Coastal communities re-embrace fishing identities, as community-based fishing, processing and marketing takes hold with new technologies. Changing attitudes and advanced technologies, such as carbon-neutral propulsion, leads to a rebirth in sport fishing.
An ecosystem-based approach constrains catch for individual fisheries, which frustrates fishermen, but the overall catch increases. Technological innovations and institutional changes offer hope for solutions.
A Blue Revolution: Gradual change, but fish decline
A warming climate and ocean causes familiar fish stocks to decline, but subtropical and tropical fish find favorable conditions along the West Coast. A more open, global economy seeks inexpensive ways to supply protein, and wild-caught fish struggle under the pressure.
Throughout the 2030s, public sentiment has increased to address carbon emissions, leading to offshore energy supplies based on wind, currents and thermal properties of ocean water. Public values move away from animal protein to seafood and plant-based proteins.
Aquaculture puts competitive pressure on large-scale commercial fisheries, but coastal communities maintain some of their character with the help of federal investments in infrastructure — including rural broadband that supports remote office work. Recreational fishing sees a resurgence but with lower catch limits.
Increasing aquaculture creates conflicts with the commercial fishing industry, and fishery management councils take on new roles in regulating offshore aquaculture.
Harmful algal blooms increase in frequency; the ecosystem becomes less productive; and marine mammal populations decline. While wild salmon have less pressure from predators, lower ocean productivity reduces their numbers. Improved hatchery practices allow for continued salmon production.
Box of Chocolates: High climate variability, good fish stocks
In this scenario, we view “a world of environmental surprises and extremes, but where stock levels increase on average” with fishermen seeing “regular boom-and-bust cycles for some key stocks.”
Species rarely seen in the Northern Hemisphere show up suddenly, allowing for harvestable levels of unusual fish. New technology becomes the key to keeping up with less predictable conditions and allowing the exploitation of available fish. Seafood marketing becomes more difficult due to the high variability in seafood supplies, but consumers seek wild-caught fish for health and emotional reasons.
In some areas, salmon fishing may be good at times, but sport fishermen cannot depend on catching fish at their old reliable fishing spots.
Snowpack melts early except in the highest elevations. California enters a prolonged period of drought, which contributes to the extinction of many wild salmon stocks.
Dams on the Klamath and Snake rivers are removed, improving prospects for wild stocks. Widespread development of alternative energy supplies continues to fuel the debate about removing dams on the mainstem of the Columbia River, but the need for water storage blunts the argument as droughts become more frequent.
Hollowed Out: High climate variability, and fish decline
Unpredictable and extreme shifts in ocean conditions upsets the traditional food web along the West Coast. Only a few stocks of fish remain at harvestable levels, and commercial fisheries practically disappear except for highly specialized commodity fisheries and part-time operations. Wild-caught fish have become a high-priced delicacy.
Recreational fishing exists but continues on its long decline. Some rural fishing communities are abandoned. Others become focused on shipping, tourism or urban waterfront homes. Because of persistent, damaging storms, waterfront communities are fortified against unprecedented waves.
Economic downturns, climate change and marine pollution become more worrisome around the globe. In many ways, the market for seafood never recovers from the economic shocks of the 2020s. People worry about species extinction and ecosystem services, putting more emphasis on protecting species and producing alternative protein sources like algae, hemp and laboratory-grown “meat.”
Even aquaculture struggles to survive, as coastal areas are seen as too polluted to produce healthy foods, and struggling facilities are battered by high winds and waves. Some land-based, closed-system aquaculture facilities provide fish to a high-end market.
Salmon are devastated by the conditions. Even with a decline in marine mammals, the combination of poor freshwater conditions and poor ocean productivity have driven many salmon stocks to extinction, while others struggle to survive.
Next steps
While these scenarios can help us visualize four different options for the future, it is important to understand that the visualizations are only as good as the assumptions that go into them. We are dealing with a multitude of both natural functions and human actions, some of which can literally change the ecosystem as well as the society in which we live.
Some things are beyond human control, but a first step toward achieving a desirable future is understanding what we can control. After that, we can go about taking actions to set the stage for the world in which our great-great-grandchildren will live.
Anyone interested in these scenarios may submit comments to the Pacific Fishery Management Council. The next step will be to identify specific challenges to particular communities, regions and people involved in the fishing industry. From those discussions will come proposed actions that could help people prepare for a better future.

Maps generated from the Salish Sea Model showing surface layer transport in the Northwest Straits (left) and sea surface salinity (right). Images: Pacific Northwest National Laboratory

PSI launches Salish Sea Modeling Center

The Puget Sound Institute is launching a new program that will use supercomputers to advance ecosystem recovery of the Salish Sea. The Salish Sea Modeling Center will allow scientists from around the region to access sophisticated computer models to predict changes in the ecosystem. Work at the center will tackle vexing environmental problems such as the changing chemistry of the Salish Sea and other mysteries puzzling scientists. The center is supported by the Environmental Protection Agency and other regional water quality partners.
If you want to understand where fish or killer whales go, or how toxic chemicals move through the ecosystem, it helps to know how the water moves. The ebb and flow of currents is fundamental to scientific efforts to protect and restore the Salish Sea.
Researchers have known for many years that they could create physical models to simulate the movements of these currents. In the 1950s, engineers created scale replicas out of concrete that used saltwater and colored dye to track the motion of processes like tidal flows and circulation. These scale models were a standard for oceanographers for more than 30 years.
Now, computer models can replace circulating dye and water pumps with just about any conceivable data. They can reveal how water temperature changes, how fast Arctic melting will raise the tideline along the shore, or when global carbon emissions will eventually turn the Salish Sea acidic. They can anticipate herring spawns or answer policy questions about where and how to clean up toxic chemicals.

A map image showing the range of the Salish Sea Model. Photo courtesy of Pacific Northwest National Laboratory.
A map image showing the range of the Salish Sea Model. The range extends beyond the boundaries of the Salish Sea to include influences from coastal hydrodynamics. Image courtesy of Pacific Northwest National Laboratory.

Providing the region’s policy leaders and scientists with these powerful tools is the goal of the Salish Sea Modeling Center, a new enterprise from the University of Washington Puget Sound Institute. The center will initially focus on expanding the capabilities of the Salish Sea Model, an advanced computer simulator developed over the past decade. The Salish Sea Model accurately describes how water, sediments, and nutrients enter and cycle through the Salish Sea, and is widely used by resource and regulatory agencies in the region. The model was developed by Dr. Tarang Khangaonkar and his team at the U.S. Department of Energy’s Pacific Northwest National Laboratory (PNNL). The work was done in collaboration with the Washington State Department of Ecology with grant support from the Environmental Protection Agency. Khangaonkar, who is both a principal program manager at PNNL and an affiliate professor at the University of Washington Tacoma, will serve as director of the Salish Sea Modeling Center. Support for the new center is provided by the Environmental Protection Agency’s National Estuary Program and other regional water quality partners.
“This is perhaps the first model of the entire Salish Sea that was built specifically for supporting ecosystem restoration and water quality management,” according to Khangaonkar, who says the massive, cross-border ecosystem posed significant challenges for developers during the early efforts. The Salish Sea’s 4600 miles of winding shoreline and its deep, underwater canyons, sills, and numerous islands were far too complex for conventional and commercially available models used in coastal applications at the time. “Computational challenges are particularly hard for our fjord-like estuary with its complex features,” says Khangaonkar. “In addition, the model must take into account runoff from 161 different watersheds, and wastewater load from nearly 100 outfalls from an ever-growing population along the shoreline.”
To capture these complexities, the model runs on a modified supercomputer consisting of up to 384 processors working in parallel (“like many desktop computers all working together,” Khangaonkar says). The result is a predictive tool that is already being applied to critical policy questions in the region. In recent years, the Washington State Department of Ecology began using the model to understand how nutrients from wastewater might be diminishing Puget Sound’s water quality. That work led to ongoing discussions about the future of the region’s wastewater treatment plants, and the model has been at the center of policy debates that could affect hundreds of millions of dollars in treatment plant retrofits.
But the model has quickly become a framework for probing many other scientific questions. Its open source software is designed to be used by anyone, and scientists from many different disciplines are now plugging in their data.
“Work at the center will focus on the use of the model to take on other issues of regional importance,” says Dr. Joel Baker, director of the Puget Sound Institute. “It allows a really well-designed and well-built model to be more widely used. We can now bring critical questions from policymakers back to the scientific community and ask, ‘Can you model this?’”
Puget Sound's orcas are among the species experiencing contamination from PCBs.
Puget Sound’s orcas are among the species experiencing contamination from PCBs.

One such question concerns the fate of toxic PCBs in Puget Sound. Scientists have noted that levels of PCBs have remained relatively constant in parts of the food web, despite efforts to remove them from sediments on the seafloor. Some theorize that legacy PCBs are entering Puget Sound through stormwater and are being cycled through the estuary without settling to the bottom. Puget Sound Institute scientists and their collaborators at the Washington Department of Fish and Wildlife are using simulations of the Salish Sea Model to better understand how important contaminants are moving throughout the Salish Sea.
“If it turns out this is true, just cleaning up the sediments may not fix the problem,” says Puget Sound Institute research scientist Andy James, one of the principal investigators on the project. Knowing how toxic contaminants move through the system could help policymakers identify the best places to focus their cleanup efforts, potentially reducing the amounts of harmful chemicals in fish that humans eat such as salmon.
Other mysteries currently being addressed by the model include the short-term effects of ocean warming on giant Pacific octopus populations, predictions of sea level rise impacts on estuary restoration, and the potential ways that eelgrass might offset ocean acidification.
In addition to its work with the Salish Sea Model, the center will also work with other organizations to combine information from computer simulations such as NOAA’s Atlantis food web model, EPA’s VELMA watershed model, or the University of Washington’s LiveOcean model which addresses water flow into the Salish Sea through the California Current.

The Cougar Creek Fire in Klickitat County, Washington, 2015. Photo: USFS

Fire danger returning to Western Washington

The National Weather Service is predicting a warmer and drier than average summer this year in Washington, prompting officials to brace for an early start to the fire season. Historically, the eastern part of the state has seen the largest impacts from fires, but climate change is now increasing the risk west of the Cascades. That could have big implications for many rural communities in the Puget Sound region. Christopher Dunagan reports the story for our magazine Salish Sea Currents.

Warm-water ‘blobs’ significantly diminish salmon, other fish populations, study says

It’s no secret that salmon and other Northwest fish populations are expected to shrink as a result of a warming Pacific Ocean. But a new study suggests that the resulting decline in commercial fishing by 2050 could be twice as great as previously estimated by climate scientists.
The higher estimates of population declines were calculated by researchers at the University of British Columbia, who took into account occasional “marine heat waves” that can play havoc with the ecosystem. A recent example is the warm-water event known as the “blob,” which included ocean temperatures up to 7 degrees above average (Fahrenheit) during a two-year period beginning in 2014.

Current sea surface temperature anomalies (variations from average) for the Pacific Coast off North and South America. The temperature scale is different from the maps above.
Map: NOAA Coral Reef Watch, April 23, 2020

William Cheung, who led the new study, told me that previous estimates of declines in fish populations assumed that the waters would warm at a steady rate as a result of climate change. But the impacts are much greater, he said, when one considers the occasional shocks to the system caused by rapid warming. Climate-change models predict at least four additional “blobs” before the end of the century, although nobody can predict when exactly they will occur.
Cold-water fish subjected to warm water face a disruption in their normal body functions, reducing the size of the fish and increasing the risk of death. Warm water also can reduce the overall production in the food web, making it more difficult for fish to find suitable prey.
For the fishing industry, marine heat waves are not unlike a sudden pandemic such as COVID-19, William said. Fishing crews can adjust to normal fluctuations in fish populations, just as health-care providers adjust to flu seasons, but sudden and stronger disruptions can lead to more serious consequences.
“Last year, management agencies closed the Alaska Pacific cod fisheries (for 2020), because they had a suspicion that the blob was returning,” said Cheung, a professor at the UBC Institute for the Oceans and Fisheries. “There was concern that the already low Pacific cod population could be hit by a heat wave that could drive the fish stocks to very low levels.”
The 2019 “return of the blob” was not as long-lasting as the 2014-16 event, but waters off the coast are still warmer than normal.
The new study, published online in the journal “Scientific Reports,” combined climate and fish models to estimate the impacts of future “blobs” from Alaska to the Gulf of California. Findings suggest that the total biomass of fish will decline, and fish will move around to establish new distribution patterns. That will decrease the amount of fish available for harvest as well as changing the location where the fish can be caught.
William Cheung

While many studies have talked about fish stocks moving around in response to changing ocean temperatures, William said biomass decreases could be a more consistent indicator for assessing the impacts of marine heat waves on various species.
During a heat wave, the average biomass of sockeye salmon in the ocean off Alaska and British Columbia is expected to decline by more than 10 percent — in addition to a biomass decrease of 10 to 20 percent by 2050 under long-term climate projections.
Of 22 fisheries included in the study, only Alaskan Pollock in the Eastern Bering Sea is expected to increase significantly in biomass during marine heat waves. Pacific sardine and Japanese mackerel may show little change.
Because sardines do better in warmer waters, long-term models tend to project increases in sardine biomass along the West Coast over time, while anchovies, which prefer cooler waters, are projected to decrease. At the same time, such models predict that both species will expand their ranges northward, producing greater numbers in the Gulf of Alaska.
But the story is different when marine heat waves are added into the picture, according to the new study. Rapid warming can push temperatures to the limit for both sardines and anchovies, decreasing their total biomass in the Gulf of Alaska as well as along the West Coast.
The study found that the fish most impacted by a combination of long-term climate change and future “blobs” were pelagic (open water) species, followed by salmon and then bottom fish. Among the five species of Pacific salmon, the biomass of sockeye salmon is expected to decrease the most — 40 percent by 2100 throughout the study area. Coho are next on the list of affected salmon.
Pacific cod, sablefish and Pacific Ocean perch were the bottom fish projected to sustain the most losses throughout the area.
Worldwide, the frequency of marine heat waves has doubled since 1982, and climate models predict they will become more frequent and last longer in the coming years.
William noted that the study was based on a climate model that uses a high rate of greenhouse gas emissions (RCP 8.5). While recent temperatures seem to be following that high-emissions trend, emission reductions would have benefits for almost all fish populations. Still, any improvements in ocean-temperature trends will lag behind improvements in atmospheric conditions because of the heat-retention properties of water.
“Our results underscore the need for a reduction of anthropogenic greenhouse gas emissions – the fundamental driver of ocean
warming — to limit challenges from marine heat waves on fish stocks and fisheries,” William said.
The fact that marine heat waves can develop rapidly demands that scientists become better at short-term predictions, he said. Meanwhile, fisheries managers are challenged to develop plans that can respond quickly to changing conditions by reducing fishing seasons or moving fishing areas.
William plans further analysis of “blobs” across the globe, with a goal of developing projections of worldwide fishery impacts. That could lead to an economic analysis of future financial repercussions expected to result from sudden warming events in many locations.
NOAA stories for further reading:

New report describes anticipated climate-change effects in Washington state

Early effects of a warming Earth have reached Washington state, as we can see from actual measurements. Annual snowpack is declining in the mountains; ancient glaciers are shrinking; sea levels are rising; and coastal waters are becoming less hospitable to sea life.
These are some of the changes outlined in a new easy-to-read briefing report titled “Shifting Snowlines and Shorelines” by the Climate Impacts Group at the University of Washington. The report is designed to bring a clear message to leaders and citizens of Washington state regarding where we have come with respect to climate change and where we may be going.
“We are seeing the consequences (of warming), even at the local level,” said Amy Snover, director of the Climate Impacts Group. “The impacts are only expected to worsen over time.”

Amy stressed the “urgent need” to do what we can to reduce the amount of warming caused by greenhouse gas emissions. At the same time, she said, people must address the problems being seen now and prepare for worse conditions in the future.
The new briefing report is a localized summary of the “Special Report on the Ocean and Cryosphere in a Changing Climate,” a 755-page report issued in September by the Intergovernmental Panel on Climate Change (IPCC). The target audience of the new brief, Amy told me, is primarily decision makers, including officials at all levels of government.
Among the findings listed in the brief for Washington state:

  • On average, spring snowpack has declined about 30 percent from 1955 to 2016.
  • In the North Cascades, the total area occupied by glaciers has decreased more than 56 percent since 1900.
  • At Friday Harbor in northern Puget Sound, sea level has risen more than 4 inches since 1934, with other amounts at other locations.
  • Peak streamflow is coming earlier in the year — up to 20 days earlier in 2002 compared to 1948 in the most snow-dominated watersheds of Puget Sound.
  • Coastal waters are warming — between 0.9 and 1.8 degrees Fahrenheit from 1990 to 2012 — while the Pacific Ocean and Puget Sound are shifting toward more acidic conditions with effects on a variety of species.

The decision to write a localized brief about sea levels and the cryosphere (frozen parts of the Earth) resulted from acclaim for the Climate Impact Group’s previous briefing, called “No Time to Waste,” which followed the IPCC special report on what people will be facing if global warming reaches 1.5 degrees C (2.7 degrees F) above pre-industrial levels. See the 616-page document “Global Warming of 1.5° C.”

For Washington state, “No Time to Waste” provides some numerical forecasts for hotter days, reduced snowpack, higher winter streamflows, lower summer streamflows and sea level rise. Predictions were derived from years of research in the Northwest along with relevant research from other regions.
“By mid-century, if greenhouse gas emissions continue on their current pathway, the average year in Washington will be warmer than the hottest year of the 20th century,” the brief states.
If greenhouse gas emissions stopped today, the 1.5-degree limit set by the Paris Agreement would not be exceeded. However, an immediate halt to emissions is impossible, of course. We are, in fact, getting close to locking in at least a 1.5-degree rise along with drastic consequences.
“Limiting warming to 1.5°C can only be achieved if action is taken to reduce global CO2 emissions by about 45% from 2010 levels by 2030 and to ‘net zero’ by around 2050,” the brief states.
Amy Snover sees a growing recognition of the climate-change problem as well as growing support for action. In fact, actions have begun in Washington state to reduce greenhouse gases and to address the anticipated problems, she said.
“That’s the happy secret of climate change,” Amy told me. “There is more happening than most people know. That being said, it isn’t really enough. It’s just the beginning, and a lot more needs to be done.”
Local governments are beginning to plan for higher water levels, as I described in a 2017 story for the Encyclopedia of Puget Sound. Many waterfront property owners also are beginning to consider their options, as I reported in a separate story.
Sea-level rise depends on two factors: how fast the oceans rise and the rate of vertical land shifts. A sophisticated analysis of these two factors in Puget Sound and along the Washington Coast give us a good idea of what we are facing under various climate-change scenarios. Check out “Projected Sea Level Rise for Washington State” (PDF 10.4 mb).
One of the great values of this analysis is that we can look at the probabilities that certain sea levels will be reached at certain times under various climate-change scenarios. We can choose just about any location by pointing to a map of Washington state, as I explained in a Water Ways blog post in August 2018. For example, I listed the projected sea-level rise in 2050 for various locations, using a 50 percent probability and a high greenhouse gas scenario:

  • Neah Bay, 0.1 foot;
  • Sekiu, 0.3 foot;
  • Ocean Shores, Ozette, 0.4 foot;
  • Aberdeen, Point Roberts, Port Angeles, 0.5 foot;
  • Bellingham, La Push, Queets, San Juan Island, 0.6 foot;
  • Anacortes, Hoodsport, La Conner, Sequim, 0.7 foot;
  • Bremerton-Port Orchard-Silverdale, Everett, Gig Harbor, Hansville, Port Townsend, Poulsbo-Suquamish-Bainbridge, Seattle, Shelton, Tacoma, Vashon Island (most), Whidbey Island, 0.8 foot;
  • Ballard, Edmonds, East Vashon-Des Moines, Federal Way, Port Ludlow, Shelton, 0.9 foot; and
  • Kingston, Olympia, 1.0 foot.

For other stories about the local impacts of climate change, please check out the Encyclopedia of Puget Sound’s sections on:

Changes were made to an earlier version of this blog post to clarify the opening sentence, the first quote by Amy Snover and the effect of an immediate halt to greenhouse gas emissions.