Why Have Harmful Algal Blooms on Lake Billy Chinook Seemingly Increased?

Across the world, reported numbers of toxin-producing harmful algal blooms (HABs) in freshwater bodies have spiked. Oregon does not escape this fate. Lake Billy Chinook has seen HABs each of the last five summers – an alarming development. These HABs threaten water quality, strain local economies, and affect the health of people, fish and wildlife, and whole ecosystems. Though many point to climate change as the spike’s main cause, that explanation fails to look at the whole picture. A better explanation for the spike is human activities, especially those that pollute water, impair water quality, and provide optimal conditions for HABs to flourish in. At Lake Billy Chinook, the major contributors are nutrient pollution from agricultural runoff, the loss of riparian habitat along its tributaries, and impounded, stagnant waters. Looking at all of these additional pressures, the increasing frequency of HABs at Lake Billy Chinook is a foreseeable outcome.

How do HABs form in the first place?

Algae flourish in warm, sunny, stagnant waters with high nutrient contents. Warm and stagnant waters allow algae to occupy the surface of the water without being disturbed and sunlight allows photosynthesis and growth. Unnatural infusions of nutrients give algae the building blocks they need to continue to grow in dense concentrations. These conditions readily result in large HABs.

Nutrient polluted freshwater systems impair water quality to algae’s benefit. Some of the largest contributors to HAB-causing water quality impairment are nutrient pollution from agricultural runoff and forestry practices, removing riparian habitat which filters runoff and provides shade, and increasing temperature through water withdrawals and stagnation. The HABs resulting from these activities point to a larger issue – freshwater systems are overtaxed by nutrient and temperature pollution and can no longer function properly.

Climate change is responsible for some water warming and providing favorable weather conditions for algae. However, if climate change was the main contributor, similarly situated freshwater bodies would experience HABs at similar rate – which they are not. Human activities that pollute and impair water quality provide a better explanation for this difference in HAB occurrence rates.

Why is Lake Billy Chinook seeing so many HABs?

Lake Billy Chinook is at the forefront of the HAB spike in Oregon. It owes this dubious distinction to the excellent conditions it provides for algae to thrive in. Nutrient pollution is high, surface water temperatures are above healthy levels, and the water is largely stagnant. With these conditions, the significant uptick of HABs at Lake Billy Chinook is not too surprising.

But how did conditions at Lake Billy Chinook get this way? Human activities throughout the Deschutes Basin are the main contributor. Agricultural runoff transported by the Crooked and middle Deschutes rivers, lost filtration and shade once provided by riparian vegetation along the tributaries, water withdrawals, and impoundment operations all impair Lake Billy Chinook’s water quality and offer optimal conditions for HABs.

The water quality situation at Lake Billy Chinook is unique in that it is largely at the mercy of its three tributary rivers for its own water quality – the Metolius, Deschutes, and Crooked rivers. Lake Billy Chinook’s nutrient pollution problem comes largely from one source – the Crooked River. Runoff from both animal feed operations and farms, which use 25% more fertilizer compared to 55 years ago, enter directly into the Crooked River. That runoff is no longer filtered by riparian vegetation. The Crooked River’s nutrient infusions, which account for 86% of Lake Billy Chinook’s dissolved nitrates, feed algae and potential blooms.

Lake Billy Chinook’s high temperature comes from many sources. Climate change, however, is not a major contributor. Over the last 20 years, surface water temperatures at Lake Billy Chinook have not increased much. On the other hand, many temperature-raising factors have stayed constant during that same period. Both the Deschutes and Crooked rivers’ temperatures are, and have been, well above the protective criteria level set by the State for the Deschutes Basin. Water withdrawals continue to reduce the amount of water in the Deschutes and Crooked rivers, allowing them to warm more quickly. Finally, impounding water both increases the exposure time of water to more solar radiation, which increases water temperature and stimulates algal growth. These conditions have persisted during the last 20 years and explain Lake Billy Chinook’s high temperatures better than climate change.


Freshwater bodies are in a constant, delicate balance with countless factors contributing to their health and status. Lake Billy Chinook provides a clear example of how the human activities are the major contributing factor to the HAB spike, both locally and worldwide. Climate change alone cannot explain this spike. Nutrient pollution and temperature-increasing human activities provide a clearer explanation. Lake Billy Chinook’s current water quality conditions provide a nutrient-rich, warm, and stable environment for algae to thrive year after year. If these conditions continue, HABs will continue to occur in Lake Billy Chinook.

History of Harmful Algal Blooms and Monitoring in Lake Billy Chinook

sww tower

For the fifth summer in a row, the Oregon Health Authority (OHA) issued a Recreational Use Advisory for Lake Billy Chinook (LBC) related to toxin-producing harmful algal blooms, or HABs. Despite this unfortunate anniversary, OHA opted to issue a season-long advisory unrelated to either a specific bloom’s presence or any testing or data that confirms toxic conditions in Lake Billy Chinook. For OHA’s explanation of this new type of advisory, please see its original advisory: https://www.oregon.gov/oha/ERD/Pages/2019-Precautionary-Seasonal-Recreational-Health-Advisory-Lake-Billy-Chinook.aspx.

In the face of annual recurrences, DRA strongly urges OHA to increase monitoring at LBC to better react and respond to the growing problem and to return to bloom-specific advisories that better advise the public of the actual conditions at Lake Billy Chinook.

  • OHA has been aware of Lake Billy Chinook’s toxin-producing harmful algal blooms since at least 2015.
  • The “Precautionary Seasonal Advisory” for LBC this year is not related to either an algae bloom or to toxicity testing results. It is unclear if any HAB monitoring is currently taking place at Lake Billy Chinook.
  • As HAB occurrences increase, more monitoring and testing is needed at LBC to better understand the problem, respond to related environmental issues, and effectively advise recreators.

Since 2004, OHA has issued HAB-related health advisories for Oregon’s freshwater bodies. These alert the public to cyanotoxins’ presence in specific water bodies – a warning to stay out. OHA issues a health advisory when cyanotoxin levels rise above the safe level for recreation. With each advisory, a monitoring, surveillance, and testing program for the specific bloom begins. Once the requisite number of tests return safe levels, OHA lifts the advisory and recreation can safely resume. Even after lifting the advisory, water monitoring samples continues until the bloom is physically gone.

Lake Billy Chinook is no stranger to these HABs or advisories. OHA issued its first advisory for LBC in 2015. Since then, LBC has seen at least one advisory each summer. In the short span of five summers, LBC has shifted from minimally impacted to facing annual blooms.


This year’s Lake Billy Chinook advisory, issued on June 11, stayed in effect until November 1. Dubbed a “Precautionary Seasonal Recreational Use Health Advisory,” this advisory differed from the previous four advisories posted for the Lake and from almost all other HAB advisories throughout Oregon. Except for the South Umpqua River advisory, which is permanently in place, LBC’s season-long advisory is an entirely new approach to warning the public. Rather than providing advisories supported by monitoring and testing data, this new style of advisory only warns of potential HABs throughout the season. Though OHA published “reminders” in July, August, and late September, they only echoed the first warning without offering any new information or data. And despite its own admission in both mid-August and late September that it knows of no toxic HABs in the lake, OHA maintains the advisory.

By issuing a seasonal precautionary advisory, HAB response at Lake Billy Chinook seemed to be in a holding pattern. Without continuous or even intermittent monitoring required, LBC had the ‘potentially unfit for recreation’ status for its entire summer recreation period. Despite the increasing frequency, OHA’s choice to issue the seasonal advisory results in almost no monitoring. Because an advisory is already in place, no bloom monitoring or testing is required to confirm the need for an advisory. Likewise, with the advisory in place until November 1, presumably no testing to track a bloom or to lift the advisory took place. Instead, Lake Billy Chinook sat by idly, recreation restricted, blooms untested, the problem largely unaddressed – with the public left wondering whether the water was actually toxic or not.

OHA’s lackluster response to the growing HAB problem at Lake Billy Chinook has serious repercussions. The first of these is to recreation at LBC. Without specific information, tourists and recreators could have relied on this advisory and foregone recreation at LBC altogether, with potentially significant impacts on the local economy. With many other recreation locations in Oregon, tourists could easily move their plans, and their business, elsewhere. All this because of the seasonal advisory that was not supported by data and without actual knowledge of a HAB in LBC.

In addition to the recreational and local economic impacts, OHA risks losing any meaning behind their HAB advisory. If OHA issues seasonal advisories as a matter of form without any supporting evidence, it will lose its significance to the public. This could lead both tourists and locals to either ignore the warning (and risk using what in fact are the actually dangerous waters) or to leave LBC behind (when in fact the danger has passed) in favor of other water bodies. Both are bad options. And both can be avoided by returning to the previous method of monitoring and advising. Already in this first year, the advisory seemed to be ineffective. Between the lack of signage, lack of clarity in the warning, and ineffective communication, many recreators were unaware of LBC’s advisory status over the Labor Day weekend. There really is no other reasonable policy option: OHA should abandon the seasonal advisory approach in order to protect the public.

While this post has focused on Lake Billy Chinook, the impacts reach beyond its boundaries. As the upstream source of water for the lower Deschutes River, the HABs in LBC are passed through the Selective Water Withdraw Tower at the Round Butte Dam. As noted in our previous reports, the lower Deschutes River already faces detrimental effects from the surface water release from Lake Billy Chinook. Migrating salmon and trout, along with downstream users, face yet another hurdle from these toxic blooms. HAB monitoring in Lake Billy Chinook, therefore, is needed for multiple reasons. Actual timely data about the blooms, and the presence of cyanotoxin, will help us understand the scope of the problem, provide more accurate warnings to protect human health, and encourage reasonable action in the public interest.

Water Quality and Aquatic Insects: A Story of Change in the lower Deschutes River

Do you ever think about the diversity and abundance of life that lives within the rocks and banks of a river? Aquatic entomologists study the organisms that inhabit the substrate, or benthic zone, in lakes and streams. The lower Deschutes River is historically well known for its abundant and diverse insect population that provide food for trout, birds, and other animals. Recent changes in the benthic zone’s appearance, including prolific algae growth, prompted concern for the aquatic insects that require clean and suitable substrate to thrive.

October caddisfly (Dicosmoecus sp.) lava. Photo by Rick Hafele.


In 2015 and 2016 the Deschutes River Alliance Science Team, with guidance from our trained aquatic entomologist Rick Hafele, collected benthic samples for analysis. We used methods developed by the Oregon Department of Environmental Quality and U.S. Environmental Protection Agency to collect and assess the macroinvertebrates at two sites in the lower Deschutes River. The 2015/2016 Lower Deschutes River Benthic Study (DRA 2019) can be found on our website: www.deschutesriveralliance.org.

Our study results are consistent with responses to eutrophic conditions (meaning excess nutrients). In this case the problem is from high loads of nutrients, primarily nitrogen from agricultural sources, and the result is poor water quality. First, our results showed low abundance of pollution sensitive species of caddisflies, mayflies, and stoneflies relative to the abundance of pollution tolerant species like worms and snails. In fact, the abundance of non-insect pollution tolerant species comprised more than 50% of all invertebrates collected from all samples during the study. The results from September 2016 are summarized below.

Deschutes River Alliance benthic sampling results for September 2016. Non-insect taxa (primarily worms and snails), EPT (mayfly, stonefly, and caddisfly taxa), and other (beetles, moths, flies) are expressed as percent relative abundance. Dizney Riffle and Kaskela are at River Mile 99 and 79, respectively, of the lower Deschutes River.

In addition, a polychaete worm was observed in high abundance.  This worm is the intermediate host of the Ceratonova (syn: Ceratomyxashasta parasite and ranged from 252 to over 8,000 individuals per square meter during the study. C. shasta is particularly concerning for the health of spring Chinook salmon in the Deschutes River. The figure below summarizes the complex life cycle of C. shasta.


Ceratonova (syn: Ceratomyxa) shasta life cycle. Source: OSU Microbiology department (https://microbiology.science.oregonstate.edu/deschutes-river)

Concurrent studies in 2015 and 2016 by Oregon State University, Oregon Department of Fish & Wildlife, and the US Fish & Wildlife Service detected high concentrations of the C. shasta spores in water samples collected in the lower Deschutes River (see “ODFW Fellowship Report 2015-2016”). Enteronecrosis (aka “gut rot”) is caused by infection of the C. shasta parasite and has caused losses of adult and juvenile Chinook salmon in the Deschutes Basin. The overall effect of this disease on the spring Chinook salmon population is currently unknown but warrants further investigation.

Low numbers of pollution-sensitive insects coupled with high abundance of parasite-hosting non-insect species continue to raise questions about water quality in the lower Deschutes River. Multiple lines of evidence now point toward the Selective Water Withdrawal Tower as the reason for the shift to eutrophic conditions in the lower Deschutes River. The Deschutes River Alliance continues to advocate for the return of cold and clean water to the lower Deschutes River in addition to monitoring the impacts of these changes.

A Successful BBQ in Maupin!

A delicious spread of burgers, hot dogs, and more sourced from the great folks at the Maupin Market.

Both the conversations and the music were lively at DRA’s first annual Maupin BBQ at Kaiser Park in Maupin last Saturday, coinciding with National Public Lands Day and the BLM’s volunteer cleanup event. Turnout and determination were high as people came together to celebrate the Wild & Scenic lower Deschutes River and renew their commitment to improve water quality of the river. 

“It isn’t too late to save the lower Deschutes River, if only all concerned will follow the science, at long last,” said Greg McMillan, president of the DRA. “There is a clear path ahead to improve the health of this waterway that provides drinking water, fish and wildlife habitat, and recreational and economic opportunities for our state.” 

The DRA didn’t let a little wind and rain stop us from throwing an awesome party. Despite the weather conditions, the BBQ carried on and the people who joined us had a great time.

The Slippery Rock String Band (with guest harmonica player Rick Hafele!) keeping the party going.

The river celebration was promoted by the Madras Pioneer, Hood River News, The Dalles Chronicle and KBND radio. And it wouldn’t have happened without the support of amazing community members. Food – including some amazing hot dogs – was coordinated by the Maupin Market. The crew at the Deschutes Angler helped run the grill. Freebridge Brewing provided beer and the Slippery Rock String Band kept toes tapping and people dancing. 

Maupin mayor Lynn Ewing, a long-time supporter of DRA’s efforts was in attendance as well as Wasco County Commissioner Kathy Schwartz.

(From left) Maupin Mayor, Lynn Ewing; DRA President, Greg McMillan; and DRA Board Member, Rick Hafele

Before the party, about 20 folks, including several DRA supporters, joined in the river cleanup along the lower Deschutes, picking up litter and detritus. 

(From left) Allison Bechtol, DRA Executive Director Sarah Cloud, and Jacky Pribyl

This was the first DRA event for new executive director Sarah Cloud. 

“I continue to be impressed and encouraged by the amazing community support for DRA and our work for science-based solutions to improve the water quality of the Wild & Scenic lower Deschutes River,” said Cloud. “This was a great event and I’m looking forward to next year when the party will be even larger.”

A family enjoys food and friends in Kaiser Park


Register Today for the DRA 2020 Gathering and Auction!


Join us for the biggest DRA party of the year! Mark your calendars and register today for the DRA 2020 Gathering and Auction! You won’t want to miss out on the afternoon celebration!


Saturday, February 8, 2020

1pm – 5pm

Montgomery Park, Portland, OR

Admission: $100 per person


Click here to register!


We will once again have delicious wine provided by Lange Estate Winery, and incredible beer crafted by Freebridge Brewing Co. Visit with new and old friends alike while enjoying a hearty assortment of appetizers from Elephants Catering – an afternoon meal in itself!


PLUS! Back by popular demand – Portland’s own Bridge City Blues Band will be rocking the house! You’ll have the change to book them for your next event, too, as we kick off the auction.


This year’s auction lineup will be jam packed with exciting trips, one-of-a-kind rods and reels, outdoor adventures and gear, regional wines and brewery experiences, and so much more! There’s guaranteed something for everyone in our thoughtfully curated live and silent auctions, and a stellar raffle to boot!


Last year’s even sold out – secure your seat at the table and register today!


Thank you to our 2020 sponsors!



DRA Releases 2018 Lower Deschutes River Water Quality Report

The Deschutes River Alliance accomplished a lot of important work for the lower Deschutes River in 2018:

None of this work would have been possible without the generous support and dedication to the lower Deschutes River of our donors.

Photo by Wesley Noone.


In addition, we are pleased to announce the release of the DRA’s 2018 Lower Deschutes River Water Quality Report. The report is a comprehensive analysis of data collected from our water quality monitoring work conducted in 2018. This monitoring continues to be an important element in our science efforts and provides invaluable insight into changes occurring on the lower Deschutes River.

What did we find? Once again, our data (in combination with our data we’ll be publishing soon on Lake Billy Chinook) finds the following:

  • Water quality in the surface water in the forebay of Lake Billy Chinook is composed of water matching Crooked River water. This seasonally warm, algae laden and nutrient polluted water forms the surface water that is drawn into the Selective Water Withdrawal (SWW) Tower and, for much of the year, is being discharged undiluted into the lower Deschutes River. Prior to surface water withdrawal, reservoir algae absorbed and utilized the excess nutrients entering the reservoir from the Crooked River.  Then later in the year, the reservoir would mix, or “turn over.”  Back then, cool, clean water was discharged from the bottom of the forebay at Round Butte Dam. Now with surface water draw at the tower, the residency time of surface water is reduced, resulting in nitrogenous nutrients being transferred to the lower Deschutes River.
  • The consequence of this surface water withdrawal is a yearly seasonal pattern of exceeding or not meeting the water quality requirements of the Water Quality Management and Monitoring Plan of the Clean Water Act Section 401 Certification of the Pelton-Round Butte Hydroelectric Complex. The exceedances are primarily for pH and temperature.
  • Dissolved oxygen is not being managed for redband trout during much of their spawning period in the lower Deschutes River.
  • Oregon Department of Environmental Quality pH data collected at the Hwy. 26 bridge on the lower Deschutes River continues to record significantly higher pH (a marker of increased nutrient pollution and algae growth) since the SSW Tower went into operation.
  • In 2018, a reduction in observed turbidity, and increased adult aquatic insect hatch activity during the month of May coincided with reduced Upper Crooked River flows.The upper Crooked River went dry just above the reservoir in mid-May of 2018.


These findings are detailed and substantiated in our annual water quality report.

Absent effective action by state and federal authorities, DRA will continue to seek to enforce Clean Water Act water quality standards as a principle means of restoring the ecological integrity of the Lower Deschutes River.

Going forward, we are also implementing a water quality monitoring program for the Crooked River.

We are eager to get our Lake Billy Chinook data published later this summer.  Watch for it in mid-July to early August 2019.

We want to give our most heartfelt thanks to our supporters for making it possible to do this work in monitoring and defending the lower Deschutes River.


Whirling Disease Not Likely in Lower Deschutes River

We received the photo below via social media a few weeks ago and we were asked if the fish in the photo was affected by “whirling disease” or Myxobolus cerebralis.



No diagnosis of whirling disease can be possible without a proper examination by someone knowledgeable in fish pathology despite the appearance of the fish.  There are other causes of the spinal and other malformations that are more likely in the lower Deschutes River trout population.

First amongst those is trauma from electroshocking.  Oregon Department of Fish and Wildlife (ODFW) has been conducting electroshocking studies in the lower Deschutes River for several years.  Trauma such as seen in the photo above, although rare, is not unusual.

This fish could also have been the victim of osprey predation as a juvenile, but managed to escape.

Myxobolus cerebralishas a relatively complicated three-stage, two-host, life cycle.  Part of that life cycle requires a tubificid oligochaete(Tubifex tubifex).  Although the lower Deschutes River has seen a large increase in oligochaetes since the implementation of surface water draw from Lake Billy Chinook, this specific oligochaete has not been identified in either of two sampling studies of benthic fauna.

There have also been no other reports of similarly afflicted fish in the lower Deschutes River.  Whirling disease tends to occur in epidemics.

At one time in the 1990s and early 2000s, there were suspicions that whirling disease might be present in the Upper Deschutes River watershed, although no publications that we are aware of substantiate that.  Whirling disease is an ongoing concern and is monitored for in hatcheries.

If you find fish with an appearance similar to that in the photo above, please photograph the fish, and if possible, get it to a local ODFW office (on ice of course!).

Everyone can help prevent the spread of whirling disease (and other invasive species like New Zealand mud snails) here and elsewhere by following guidelines for cleaning waders and wading boots.  Here is information on how to clean your gear: