King County scientists see unprecedented harmful algal bloom in Puget Sound

On June 16, field scientists from the King County Environmental Laboratory were collecting routine water quality samples aboard the research vessel, SoundGuardian, in the Central Basin of Puget Sound. As they were sampling, they noticed some patchy, brown coloration at the water’s surface at several sites visited that day.

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Blooms of Heterosigma akashiwo can develop very quickly and form conspicuous brown patches at the water’s surface where they congregate during the day. This flagellate can bloom in high numbers multiple times per season. (Photo: Gabriela Hannach)

The samples were analyzed and determined to be a dense bloom of a tiny, harmful flagellate known as Heterosigma akashiwo. A regular component of Puget Sound’s phytoplankton community, Heterosigma has the dubious honor of belonging to a group known as Harmful Algal Bloom (HAB) species. Heterosigma has been repeatedly associated with fish mortality.

The highest concentration of Heterosigma measured in the last six years reached 2 million cells per liter in the protected waters of Quartermaster Harbor. Last week’s bloom reached numbers as high as 4 million cells per literCell densities of this magnitude are rarely observed in Puget Sound’s main basin.  It is the largest Heterosigma bloom King County scientists have observed in the history of the phytoplankton monitoring program in Puget Sound’s Central Basin.

The FlowCAM instrument is an automated imaging microscope used at the King County Environmental Lab to study phytoplankton cells in water samples. (Photo: Lyndsey Swanson)

A common and globally distributed coastal species, Heterosigma often blooms in shallow recesses of Puget Sound’s shoreline, but much less frequently in the mixed waters of its three deeper basins.

Puget Sound is home to many different types of HABs that exhibit a wide range of troublesome effects for people and wildlife. Heterosigma has long been associated with fish kills and while the exact mechanism is not yet clear, there is some evidence that it produces hydrogen peroxide (a reactive oxygen species) which can cause gill damage and lead to anoxia and respiratory failure.

Scientists believe the explosion of Heterosigma cells was enabled by a period of rainy weather that established a stable surface layer of nutrient-rich, low-salinity water where these cells could thrive and reproduce readily. It is extremely unlikely the bloom was related to the West Point Treatment Plant as the bloom is occurring all over central Puget Sound; the plant’s performance has been normal with no overflows; and the effluent quality has been excellent.

A clear relationship between Heterosigma blooms and rising spring temperatures has been documented in field studies, suggesting that as the average global temperature rises, we could see an increase in the frequency of blooms of this toxic flagellate in Puget Sound waters.

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Above are microscopic photos of individual particles detected in water samples arranged in a collage by the FlowCam instrument. The golden, oval-shaped particles in this collage are Heterosigma akashiwo collected from the recent bloom. (Photo: Gabriela Hannach)

Since 2008, the King County Environmental Laboratory has monitored the phytoplankton community of the Central Basin of Puget Sound, using microscopy to document the enormous variety of phytoplankton that inhabit these waters.

King County shares data with local agencies to share and inform aqua-culturists and other relevant agencies as an advanced warning, thereby helping to protect local industry from the potentially deleterious effects of this harmful species.

Heterosigma akashiwo is a small, photosynthetic flagellate common to Puget Sound waters. It is best known for its cartwheeling swimming pattern, cornflake-like appearance, and association with fish kills. (Video: Lyndsey Swanson)


Cochlan,W.P., Trainer, V.L. Trick, C.G., Wells, M.L., Eberhart, B.-T. L., Bill, B.D. 2013.Heterosigma akashiwo in the Salish Sea: defining growth and toxicity leading to fish kills. Proceedings of the 15th International Conference on Harmful Algae.

Glibert, P.M., Anderson, D.M., Gentien, P., Grane´li, E., Sellner, K.G., 2005. The global, complex phenomena of harmful algal blooms. Oceanography 18 (2), 136–147.

Taylor, F. J. R., Haigh, R. 1993. The Ecology of Fish-Killing Blooms of the Chloromonad Flagellate Heterosigma akashiwo in the Strait of Georgia and Adjacent Waters. In: Smayda, T. J. and Shimizu, Y. (eds.). Toxic Phytoplankton Blooms in the Sea. Elsevier, Amsterdam. 705-771

Horner, R. A. 2002. A Taxonomic Guide To Some Common Phytoplankton. Biopress Limited, Dorset Press, Dorchester, UK. 200.

Steidinger, K.A. & Meave del Castillo, M.E. [Eds.] 2018. Guide to the Identification of Harmful Microalgae in the Gulf of Mexico.(Vols. I-II). St. Petersburg, FL; DiggyPOD, Inc.

Swanson, L.M, & Hannach G.; “Harmful Algal Species in the Central Basin of Puget Sound: Seasonal Bloom Patterns Analyzed Via FlowCAM Technology.” Salish Sea Ecosystem Conference 2020 (Digital poster presentation). King County Environmental Laboratory, Seattle, WA.

Rensel, J.E.J., 2007. Fish kills from the harmful alga Heterosigma akashiwo in Puget Sound:  Recent blooms and review.

Saving SoundGuardian

by Rachael Hartman and Saffa Bardaro
View of the lumberyard fire behind the King County Environmental Lab from across the Fremont Cut.

On the night of Saturday, Nov. 10, a four-alarm fire started at a lumberyard right across from the King County Environmental Lab.

The fire was the largest Seattle has seen since 2010 with flames shooting over 100 feet into the air, according to the Seattle Fire Department blog. In the end, the fire that burned two buildings to the ground and damaged three others was determined to be arson.

That night, in addition to the 142 firefighters that helped fight the fire, King County employees were coordinating their own response to protect the Lab and the SoundGuardian research vessel. The 4-alarm fire was less than 200 feet away from the Lab which worried employees that both the Lab and SoundGuardian were at risk.

“I got a call from Ben Budka, the Lab’s Field Science Unit Supervisor and Trouble Call Coordinator, at about 9 p.m. Saturday night” said Diane McElhaney, Environmental Lab Manager. “He said, ‘It doesn’t look good. Bob [Kruger, SoundGuardian captain] and I are going to try to save SoundGuardian.’

The lumberyard where the fire occurred is across the street from the Lab.

Diane began wondering where they could take SoundGuardian if it had to be moved. And though the Lab is concrete, she knew water damage to the equipment could be catastrophic. When Diane met up with Ben, Bob, and, by then, Terry Siebens, Conventionals chemist, at the Lab just before 10 p.m. she could not believe what she saw.

“There were 15 fire trucks, as well as fire boats in the canal. The Lab was filled with smoke,” said Diane. “You could see the spray of water from the fire boats going over the road in huge arcs.”

The aftermath of the fire: Not only were buildings and cars destroyed but tarps of boats just five slips down from SoundGuardian – in the Canal Marina – melted. The Lab is the grey building is in the background on the left

After hearing from fire officials on the scene that they had contained the fire, Lab employees decided that SoundGuardian did not need to be moved. Power infrastructure, however, had been damaged so power was off for several blocks and would remain off for several days. So the next concern was preventing a power surge at the Lab when electricity eventually came back.

“We went around the Lab and unplugged everything we could find,” said Diane. Previous outages had taught Lab employees that equipment needed to be brought back up in stages. After Ali Wandy (Building Engineer) joined Diane around midnight to make sure the bigger systems were shut down, they called it a night knowing there was much more work to be done in the coming days.

The aftermath of the fire – not only were buildings and cars destroyed but tarps of boats just five slips down from SoundGuardian had melted. The Lab is the grey building in the background on the left.

While the Lab is housed under the Water and Land Resources Division, Wastewater Treatment Division (WTD) employees cover safety for the Lab as well as construction management. In the face of a power outage, the two divisions had to consider how they were going to keep Lab samples cold for several days. WTD construction managers started looking at the possibility of getting a generator out to the Lab. A refrigeration truck was also considered, as was dry ice.

“We wouldn’t have lost all the samples, but they could have been compromised after 24-48 hours of reduced temperatures,” said Diane. “We have microbiology samples that need to be held at minus 80 degrees in some cases.” Fortunately, county and city leadership made it a priority to get power restored by Tuesday, Nov. 13 at about 4 p.m.

While there was no visible damage to the Lab, it “smelled like a campfire,” said Mark Palmer, WTD construction manager. By chance, Monday, Nov. 12 was Veterans Day, and a King County holiday, providing an extra day for the Lab to air out.

The fire also threatened the progress of a 16-month project to replace the Lab’s fume hood and air handling equipment with more energy-efficient systems.

One of the first shipment of fume hoods being replaced in the Lab.

“Diane called on us to help with the smoke that had been sucked into the Lab,” explains Allen Alston, safety officer. As a precaution, Allen and Bud McJimsey, WTD construction manager, worked with an air-sampling contractor to test the air quality in the Lab for both smoke and volatile organic compounds (VOCs) – gases released from burning materials that could be hazardous to people’s health.

“We wanted to ensure people weren’t exposed to poor air quality conditions,” said Allen. Everything came back good – which confirmed it was safe for the Lab staff and construction crews to return.”

“This incident was a good reminder about keeping emergency procedures and notification lists up to date,” said Diane. “I want to thank Ben Budka, Bob Kruger, Terry Siebens, Ali Wandy, Allen Alston, Mark Palmer, William Sroufe, Ken Bergstrom, Jim Faccone, and Josh Baldi for the immediate support they provided. We’ve had so many challenges these past two years and we could not have made it without this ‘A team.’”

Continue reading Saving SoundGuardian

The Point Williams Buoy

On March 29, the crew of SoundGuardian, King County’s marine research vessel, re-deployed a water quality buoy that got loose earlier in the month at Point Williams, off Lincoln Park in West Seattle. In this video, watch Jim Devereaux, Bob Kruger, Houston Flores, and Christopher Barnes from the King County Environmental Laboratory re-anchor the buoy.

The Point Williams buoy is one of four automated, high-frequency data collection systems used by King County in marine waters and is the only floating platform — with the other three attached to piers or docks at Seattle Aquarium and inner and outer Quartermaster Harbor on Vashon-Maury Island. King County began using automated systems back in 2008 but the Point Williams buoy has been at the current location since 2013.

Sensors are used to continually collect data that is used to monitor water quality in Puget Sound.

The buoy functions as a platform to suspend multiple instruments into the top of the water column to take measurements that determine water quality in the Central Puget Sound basin.  Automated, water quality data collection allows measurements to be taken every 15 minutes of physical, chemical, and biological parameters. The result is improved information to determine variability on a weekly, even daily,  basis compared to traditional water quality measurements that are typically measured every two to four weeks.

The sensors are attached to the buoy which acts as a floating platform.

The data are transmitted via a cellular modem to a cloud data collection service, then transferred to the King County mooring data website where it can be viewed or downloaded within 30 minutes of data collection. Data undergo automatic quality checks to assess for issues in real-time as well as semi-annually by a data manager.

The data are used to characterize Puget Sound water conditions on numerous time scales (e.g., daily, seasonal, annual, inter-annual) and used for status and trends analysis, to compare with data from other locations in Puget Sound to assess spatial differences, populate or validate numerical Puget Sound models, and provide data for management decisions. The data from this water quality monitoring system are also sent to Northwest Association of Networked Ocean Observing Systems to be included in a larger marine waters data collection network.

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SoundGuardian powers through its first marine buoy inspection


Crossposted from Clean Water Stories

The SoundGuardian, King County’s new research vessel, made its first official marine run on August 1, 2016, and it is already providing benefits. Crews have been able to go farther faster and work in windy conditions that would have turned its predecessor around.

On a chilly December 1st afternoon, crews from the King County Environmental Lab carried out the first marine buoy inspection.King County’s marine buoys, or moorings, work around the clock collecting data that tells us what is  going on with our waters. Tracking water quality helps spot trends and guides management decisions.

Inspections make sure that the shackles and lines that help anchor marine buoys are in good condition.  They can corrode in marine environments and get damaged.  Problems with these lines can have unintended consequences, like the time in 2014 when a buoy ended up on a West Seattle beach.

The previous research vessel, the Liberty, was a workhorse that provided great service for 40 years.  But the Liberty just didn’t have the power to manage the big marine buoys  designed to weather rough waters that whip up on Puget Sound.  To re-deploy that runaway buoy beached in West Seattle, King County had to hire a contractor.

Beached buoy, 2014

The previous research vessel, the Liberty, was a workhorse that provided great service for 40 years.  But the Liberty just didn’t have the power to manage the big marine buoys  designed to weather rough waters that whip up on Puget Sound.  To re-deploy that runaway buoy beached in West Seattle, King County had to hire a contractor.

Marine contractor re-deploying the errant buoy

liberty (1).jpgThe SoundGuardian provides a lot more lifting power than the Liberty.  Today, crews can lift the buoy completely into the boat and conduct inspections on the deck. Crews don’t have to stand on the swim platform and inspect the suspended buoy. King County can deploy and retrieve buoys without hiring a contractor.

The SoundGuardian is already helping Environmental Labs get to work locations more quickly, and to fit more work in the day. With the boat’s greater lifting power, Environmental Lab crews can safely perform “health checks” and maintenance on this critical equipment that monitors the health of our waterways.crewdec1

Read more Clean Water Stories.