pH Violations in the Lower Deschutes River: Why it’s Happening, and Why it Matters

Round Butte Dam and the Selective Water Withdrawal Tower.

There’s been a great deal of focus on how Selective Water Withdrawal (SWW) operations at Pelton Round Butte have impacted temperatures in the lower Deschutes River. It’s hard not to focus on temperature: it’s something we can easily sense and monitor, and increased spring and summer temperatures have led to some alarming changes in the lower river these last few years.

But to understand the full extent of the ecological changes occurring in the lower river, there’s another criteria that’s perhaps even more important: hydrogen ion concentration, better known as pH. pH levels in the lower Deschutes River have increased dramatically since SWW operations began, and discharges from the Pelton Round Butte complex have routinely violated Oregon’s pH standard. Why is this happening, and how are these increased pH levels impacting the lower Deschutes River?

What is pH?

pH is a numeric scale used to indicate the acidity or basicity of a water-based solution. Pure water is neutral, with a pH of 7 standard units (SU). Solutions with a pH above 7 SU are basic (alkaline), and solutions with a pH below 7 SU are acidic. pH is measured on a logarithmic scale, meaning that a pH of 9 is ten times more alkaline than a pH of 8.

In freshwater systems like the Deschutes River, high pH levels are often the result of increased photosynthetic activity. This is because photosynthesis lowers the dissolved CO2 concentration in the water, which in turn reduces the carbonic acid concentration, which raises pH. As a result, high pH levels are a useful indicator of excessive algal growth and nutrient enrichment in freshwater systems.

Post-SWW Violations of Oregon’s pH Standard

Oregon’s water quality standard for pH in the Deschutes Basin is a minimum of 6.5 and maximum of 8.5 SU. This standard is designed to protect aquatic life from the harmful effects of water that is too acidic or too alkaline. While a pH above 8.5 is not lethal to aquatic life, it does not provide adequate protection; pH levels above 9.0 have been found to cause stress responses in rainbow trout, including sluggish movement, reduced feeding, and ammonia intoxication. High pH also indicates excessive algal growth in the river. The water quality certification for the Pelton Round Butte Complex mandates that discharges from the Project fall within this 6.5-8.5 range, to ensure that Project discharges comply with Oregon’s pH standard and that aquatic life in the lower river is adequately protected.

Since SWW operations began, Project discharges have routinely exceeded the 8.5 maximum standard. In 2016 alone, PGE’s own data show 140 days that pH levels rose above 8.5 at the Reregulating Dam tailrace.

While these numbers are alarming, downstream the problem appears to be even worse. In 2016, the DRA operated a data sonde one mile below the Reregulating Dam, collecting hourly readings for several water quality parameters, including pH, from February through November. Data collected at this site are summarized and analyzed in the DRA’s 2016 Lower Deschutes River Water Quality Report.

The pH data collected at this downstream sampling site are truly concerning. Of the 279 days sampled, 234 days had some pH measurements that exceeded the upper pH standard of 8.5. 120 of these days had pH measurements recorded above 9.0, and pH levels did not drop below 8.5 throughout April, May, and June. pH rose above 9.5 (remember, 10 times more alkaline than a pH of 8.5, and a hundred more times alkaline than a pH of 7.5) on two occasions: July 12 and October 14.

It makes sense that pH levels one mile downstream would be even higher than those in the Reregulating Dam tailrace. Increased algal growth in the river below the Project is increasing the amount of photosynthesis occurring in the river—this increased photosynthesis, in turn, continues to drive up pH levels downstream.

What do These Violations Mean, and Why are They Happening?

These newly elevated pH levels in the lower Deschutes River raise two important questions. First, what do these highly alkaline levels mean for the ecology of the lower river? As indicated above, in freshwater systems high pH levels are a strong indicator of excessive algal growth caused by nutrient enrichment. This will come as no surprise to anyone who has seen (or slipped on) the now-omnipresent nuisance algae blanketing the lower river’s rocks for much of the year. And such a high level of sustained pH poses definite stress and health risks to aquatic life including salmon, steelhead, and resident native trout.

Algae on rocks, one mile below the Pelton Reregulating Dam.

The next question that must be asked is: why is this happening? What is responsible for these elevated levels of pH? The only realistic answer appears to be the commencement of SWW operations.

Before SWW operations began in December 2009, discharges from the Pelton Round Butte Project did exceed Oregon’s pH standard from time to time. But these exceedances were relatively rare: PGE and the Confederated Tribes of Warm Springs, in their 2001 application for the Project’s water quality certification, identified only one instance between 1994 and 1999 where pH below the Reregulating Dam exceeded 8.5. In 2007-2009, the three years immediately before SWW operations began, PGE’s water quality reports show far fewer violations of the 8.5 standard.

Further, Oregon DEQ data collected at the Warm Springs Bridge from 2005-2015 show an immediate and sustained increase in exceedances of the 8.5 standard upon commencement of SWW operations.

Clearly, surface water releases through the SWW tower have had a significant impact on pH levels in the lower Deschutes River. This surface water originates in the Crooked River, the warmest of the three tributaries that enter Lake Billy Chinook, and the tributary with the highest nutrient concentration. As a result, more surface water release means more nutrients are transferred to the lower Deschutes River. This in turn has triggered a significant increase in the growth of periphyton algae in the lower river, which has increased photosynthesis, and pH levels along with it.

The encouraging news about these harmful pH levels is that the solution is right in front of us. To lower pH to levels that are again safe for the river’s aquatic life, the Project operators can significantly increase the percentage of water drawn from the bottom of Lake Billy Chinook. Doing so would slow the Project’s nutrient transfer to the lower river; this would be beneficial not only for pH, but also for the health and diversity of the lower river’s aquatic insect populations and the fish and wildlife that depend on them.

The Pelton Round Butte Project’s current pH violations are at the root of our Clean Water Act lawsuit against Portland General Electric. We’ll be working diligently this year to ensure that these violations—and their resulting ecological impacts—are addressed.

Sources

Wagner, E.J., T. Bosakowski & S. Intelmann (1997). Combined Effects of Temperature and High pH on Mortality and the Stress Response of Rainbow Trout after Stocking. Transactions of the American Fisheries Society. 126:985-998.


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Announcing the DRA’s 2016 Lower Deschutes River Water Quality Report

We are thrilled to announce the publication of the DRA’s 2016 Lower Deschutes River Water Quality Report. This report—along with three other reports we’ll be releasing over the next two months—is the culmination of the DRA’s most detailed investigation yet of the causes and extent of the ecological changes occurring in the lower Deschutes River.

An important aspect of the report analyzes hourly water quality data collected at River Mile 99, one mile below the Pelton Reregulating Dam, from February 18 through November 22, 2016. All data collected for pH, temperature, and dissolved oxygen are presented and analyzed, and compared against water quality requirements contained in the state-issued Clean Water Act § 401 Certification for the Pelton-Round Butte Complex, as well as Oregon’s water quality standards for the Deschutes Basin. Read the whole thing here.

This report represents the most complete public analysis yet of the impact of Selective Water Withdrawal operations on water quality below the Pelton-Round Butte Hydroelectric Complex. Key findings include:

  • Oregon’s water quality standard for pH in the Deschutes Basin (6.5-8.5 SU) was exceeded on 234 out of 279 days that data were collected (84%). 43% of the days sampled had pH measurements greater than 9.0.
  • Each year since 2011, Project operators have worked with the Oregon Department of Environmental Quality to purportedly weaken the water quality requirements in the Project’s Clean Water Act § 401 Certification. These changes include:
    • The defined spawning season for salmonids was changed from year-round to Oct. 15-June 15. This change allows the application of a lower dissolved oxygen standard during the non-spawning period (June 16-Oct. 14). However, this newly defined spawning period does not take into account the full season of resident trout spawning and egg incubation, as is required by the Oregon Administrative Rules. This has caused dissolved oxygen levels in the lower Deschutes River to fall below levels required to protect resident salmonids through egg incubation and fry emergence.
    • The water temperature that triggers the blending of cool bottom water from Lake Billy Chinook with warmer surface water has been markedly increased since the Selective Water Withdrawal tower began operations. This has allowed the release of 100% surface water into the lower Deschutes River to continue later into the summer.
  • Changes in pH and dissolved oxygen, documented by this study and ODEQ’s own data, clearly indicate that excess nutrients are being released into the lower Deschutes River from the surface waters of Lake Billy Chinook.

DRA’s 2016 Lower Deschutes River Water Quality Report clearly establishes that, in just seven years of operation, the Selective Water Withdrawal tower at Pelton-Round Butte has severely degraded water quality and threatens aquatic life below the Project. We believe this report will serve as an important document for all basin stakeholders in assessing the impact of tower operations on the river we all love.

A special thanks to all of our supporters, whose generosity and passion for the river has made all of our science work possible. We’d like to take this opportunity to specifically thank the various organizations and foundations who have provided funding to support this critical work, including:

  • The Oregon Wildlife Heritage Fund
  • Maybelle Clark MacDonald Fund
  • Flyfishers Club of Oregon/Flyfishers Foundation
  • Clark-Skamania Flyfishers
  • Mazamas
  • American Fly Fishing Trade Association
  • Tualatin Valley Chapter of Trout Unlimited
  • Washington County Fly Fishers

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Photo by Brian O’Keefe



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2016 Stonefly Hatch: A Recap

Photo by Rick Hafele.

Photo by Rick Hafele.

It’s come and gone. No one is even talking about it any longer. Why? Well, it wasn’t exactly epic. Or was it?

Here’s the lowdown on the 2016 stonefly hatch based on personal observation; reports from friends, guides and outfitters; emails; and reports to our hatch observer database. This collectively represents hundreds of fishing days, if not over a thousand. None of this will be a surprise to those who were there for it. And many were there! The annual stonefly hatch remains the single largest trout fishing frenzy on the lower Deschutes River.

The first salmonflies were seen mid-April once again this year. Golden stones were seen not long after. Both were first spotted down below Sherars Falls. The big bugs appeared very sporadically until early May. Then numbers began to pick up and the hatch spread further upstream to well above the locked gate at the upper end of the access road above Maupin.   There were a few scattered reports of good numbers of stoneflies during that time. If you were fortunate enough to be on the river those days, the fishing was off the hook.

Then harsh weather set in. It got colder and there were heavy rains and the hatch all but disappeared but for a few hardy bugs clinging to grass and alder leaves.

Days later, the bad weather turned back to good weather and the hatch started back up, progressing up to the Kaskela area. Once more, if you were on top of the hatch in the right location, fishing was excellent. Then once again the weather turned wet and cold for days on end. The bugs again became hard to find. The quality of the fishing suffered. The last guide report of large numbers of salmonflies or golden stones seen on the river was May 17th. Only low to moderate numbers were seen after that until the final observed golden stones were reported on June 5th.

Photo by Brian O'Keefe

Photo by Brian O’Keefe

When weather conditions in the canyon were wet and cold, it was hard to find a stonefly anywhere. The trees and grass were bare. The big bugs were hiding from the conditions. If they aren’t out crawling all over the place, they aren’t finding mates. If they aren’t finding mates, no mating takes place.

This pattern repeated itself three times. Finally a meager representation of the hatches of earlier years hung on for about a week and half, reaching all the way up to Dizney Riffle. Then it fizzled out all together.

Mixed in with the stoneflies in mid-May was about a week and half period where everything was hatching. Green drakes, pale morning duns, pale evening duns, Beatis, caddis, it was all happening at once. There were even a few Antocha crane flies seen! But all of that ended as quickly as it began. And the total numbers weren’t all that exciting. It was perplexing to see June and July hatches in mid-May.

We are still getting some reports of good numbers of caddis in the tops of alders at last light on calm evenings. But the mayfly hatches of early to mid-summer are now totally missing in action.

What meaning does all of this have for the lower Deschutes River and the future of aquatic insect species? If this year had been a one time, one-off affair, it would probably mean little, being what biologists call annual variability. But it’s become a common way for spring to unfold on the lower river.

Most disconcerting is the role this might be playing in stonefly reproduction. Salmonflies emerge after three to four years as nymphs, golden stones after two to three years as nymphs.   Any impact of this year’s weather on mating won’t be seen until 2018 to 2020. The problem is this: with warmer winter and early spring river temperatures as a consequence of surface water withdrawal at Round Butte Dam, stoneflies emerge sooner and into the often harsh conditions of early spring, not late spring/early summer as they used to. The consequence is that reliably they are now challenged to find mates and get their reproduction needs accomplished.

Anyone who has spent years on the lower Deschutes River knows that stonefly numbers are down. Way down. According to Portland General Electric’s Lower Deschutes River Macroinvertebrate and Periphyton Study (page 97), “Stoneflies were not numerically abundant, but were widely distributed and contributed substantially to the invertebrate biomass by virtue of the often large size.”  That was some nice positive spin in the end of that quote, but the reality is that stoneflies are no longer “numerically abundant.” Unlike with many of the mayfly species and Antocha crane flies, this is probably not linked to the nuisance algae growth in the lower river.

Salmonflies as nymphs are detritivores, meaning they scavenge broadly across a river bottom eating dead material, mostly from plants. Golden stoneflies are roving predators and tend to feed on slow moving macroinvertebrates like midge larvae and worms. So the documented increase in worm populations in the lower river should be benefiting them. Nuisance algae are less likely to affect stoneflies as they spend time crawling between or under rocks, avoiding the algae covered top and side surfaces.

That means the declining numbers are most likely due to something else. Most likely that “something else” is hatching early into weather conditions not conducive to mating activity for much of the short adult phase of their relatively long lives. If reproductive success declines, the population declines.

June was a much warmer, drier month than May this year (like most years) on the lower Deschutes River. We’re guessing the stoneflies would have preferred those conditions.

Photo by Brian O'Keefe.

Photo by Brian O’Keefe.

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The Problem With the Water Quality Data in the PGE Lower Deschutes River Report by R2 Consultants

Pic 1 R2 Report

The above report (published in March of this year), as noted in prior DRA blog posts, was of a two-year study of the lower Deschutes River. The purpose of the report was to determine the magnitude of biological changes in the river due to the implementation of surface water withdrawal at Round Butte Dam. A baseline study was conducted in 1999-2001, which Portland General Electric (PGE) summarized in a report published in 2002.

Both studies were contracted and paid for by PGE and were a requirement of the Federal Energy Regulatory Commission license to operate the Pelton-Round Butte dams.

The water quality data from the most recent study can be found on pages 47 and 48 of the 2014-2015 report. The results document violations of the basin and statewide water quality standards in both years of the study. The most egregious violations were of the pH standard as established in Oregon Administrative Rules (OARs) 340-041-0021 and 340-041-0135. The Deschutes Basin Standard for pH is a maximum pH of 8.5. A pH of 7.0 is neutral (neither acid nor alkaline, greater than 7 is alkaline).

The authors attempt to diminish these violations by noting on page 46 of the report that, “Regarding the unusually high pH measurements taken in Spring 2015, since these are uniformly high, even in the reference sites, it is highly likely that the meter we used was off in its calibration. Therefore, any in situ measurements taken should be considered preliminary at best, and compared to official measurements taken by PGE or agencies.”

There are many problems with this statement.

R2 Resource Consultants are self-proclaimed experts in water quality monitoring and modeling, so one has to wonder how and why they would be unable to produce accurate water quality data? Why would they have calibration problems? If their equipment wasn’t functioning properly, why wouldn’t they use backup pH measuring equipment? If they didn’t have backup equipment, why couldn’t they borrow equipment or have it shipped in via overnight express? The pH measurement problems they most specifically refer to occurred over several days in April of 2015. That should have been enough time to correct any equipment problems.

There were also very high pH measurements in the three days of sampling in April/May of 2014 (10 out of 12 lower Deschutes River sites were above the 8.5 pH water quality standard). Were their instruments faulty then too?

Or is this an attempt to discard and disregard data that are indicative of water quality problems?

There is another potential reason that the high pH values were recorded during spring sampling in both years. When algae bloom, it increases pH. It does this by absorbing CO2 from water to conduct photosynthesis. The by-products of photosynthesis are sugar and oxygen. Notably, the dissolved oxygen levels on the dates of the high pH levels were also high, with dissolved oxygen saturation levels reaching up to 138%. This occurs when there is excessive algal growth.

We have noted extensive algae growth in the lower river this year, starting in February. We have also recorded pH levels of greater than 9 in April and May 2016.

Algae, early March 2016. One mile below Pelton-Round Butte Reregulating Dam.

Algae, early March 2016. One mile below Pelton-Round Butte Reregulating Dam.

Algae, late March 2016. One mile below Pelton-Round Butte Reregulating Dam.

Algae, late March 2016. One mile below Pelton-Round Butte Reregulating Dam.

We are troubled by the lack of explanation for R2’s “calibration problem(s).” It is standard procedure to have a quality control plan that includes details for meter calibration and procedures if they fail calibration. At the DRA, we maintain a log for each instrument we own. Recorded in each of these logs are the calibration dates, times and results. All instruments are calibrated before each day of water quality sampling. We carry backup equipment.

In the case of our in-river dwelling data instrument, once a month we perform “field audits” where we cross check the data it produces with independent meters and manual techniques. We cross check the performance of our meters.

We have such a stringent quality control program because two of our field staff worked for the Oregon Department of Environmental Quality (ODEQ) for decades, doing water quality work. We exercise the same quality control methodology that ODEQ uses. We would suggest that PGE require the same of contractors doing water quality work.

DRA water quality staff at work:

Larry Marxer measuring dissolved oxygen in river water, using the Winkler method.

Larry Marxer measuring dissolved oxygen in river water, using the Winkler method.

Rick Hafele doing water quality measurements on Lake Billy Chinook.

Rick Hafele doing water quality measurements on Lake Billy Chinook.

Greg McMillan going old school on water quality measurements in 1979 (when old school was just school, or maybe pre-school).

Greg McMillan going old school on water quality measurements in 1979 (when old school was just school, or maybe pre-school).

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2015 Lower Deschutes River Aquatic Insect Hatch Activity Survey Results Report by Rick Hafele Now Available

The annual DRA aquatic insect hatch observation report for 2015 is posted to our website. Please click here to access the report.

Photo by Rick Hafele

Photo by Rick Hafele

This report, authored by Rick Hafele, is the result of the many hatch observations in 2015 by several professional guides on the lower Deschutes River. All observers received training at a Deschutes River Alliance workshop in Maupin in March of 2015. They then utilized a mobile device app to report their observations.

We want to give special thanks to the guides who participated (and continue to participate in 2016) in this process. They are: Brian Silvey, John Smeraglio, Evan Unti, Harley Faria, Alex Gonsiewski, and Dan Anthon. We would also like to thank Dave Moskowitz and Rick Trout for the reports they furnished.

The observations are summarized in this report. A continuing trend of earlier hatches, and of fewer and less dense hatches is noted once again in 2015. These trends were seen throughout the months of March to October. Declines from the previous two years were observed for all major groups of insects except midges, which remain unchanged.

Antocha crane fly adult. Photo by Rick Hafele.

Antocha crane fly adult. Photo by Rick Hafele.

The report is 29 pages long and full of information any angler needs to better understand fly-fishing the lower Deschutes River, as well as the trends in aquatic insect populations that have historically occupied the Deschutes River.

The DRA is especially grateful to Rick Hafele for his expertise in aquatic entomology and for the work he put into conceiving and organizing this ongoing monitoring effort, the collating and analysis of the observational data, and the writing of the report.

We intend to continue this monitoring effort to provide surveillance of the long-term trends in lower Deschutes River aquatic insects. The training for the 2016 hatch observers took place in March. We are already receiving their reports for the 2016 report. We’ve also added two benthic (river bottom) kick-sample sites that we began sampling in the fall of 2016.   Since Portland General Electric completed their macroinvertebrate and periphyton sampling in April/May of 2015, no one other than the DRA is monitoring aquatic insect populations in the lower Deschutes River.

Chuck Kenlan with an early evening fish that rose to a caddis imitation. Photo by Greg McMillan.

Chuck Kenlan with an early evening fish that rose to a caddis imitation. Photo by Greg McMillan.

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Portland General Electric Releases Report and Results Of Two Year Study of Lower Deschutes Macroinvertebrates and Periphyton

Study described as finding “post-Selective Water Withdrawal conditions similar to pre-Selective Water Withdrawal, or improved.”

The final report for the Portland General Electric Company’s Lower Deschutes River Macroinvertebrate and Periphyton Study was presented on April 6th and 8th, at meetings hosted by PGE.  R2 Resource Consultants of Redmond, Washington conducted the study, which was completed under contract to, and funded by, PGE.  It was a two-year study conducted over two months (April and October) each year starting in October 2013.  The study was a required condition of the Federal Energy Regulatory Commission licensing of the Pelton-Round Butte Hydroelectric Complex.

Yes, you read the stated conclusion of the study correctly.  Conditions in the lower Deschutes River are “not significantly different, post implementation of surface water withdrawal at Round Butte Dam in 2009, than conditions prior to surface water withdrawal.” In fact, according Tim Nightengale of R2 Resource Consultants, the “health of the river is probably better(!) now.”   (We have been unable to find this actual statement in the published version of the study.)  So why the serious disconnect between the described study results and what we are seeing on the lower Deschutes River?

As one property owner said at the Portland presentation of the study results, “I’ve been on the river for over fifty years and the river has never looked like it has in the last few years.”  His disappointment was that none of the negative changes are reflected in the report.  We had the same disappointment.

Again, why the disconnect?

Over the next few months we’ll be answering that question.  The full published version of the study is a 283-page pdf file.  It will take us some time to fully analyze the study and its purported results.   There appear to be a large number of issues that require full examination.

We will also be sending the study out for review and analysis to independent experts.  Following those reviews, we will be publishing an analysis and critique of the study.  We expect this process to take two to three months.

For now, we do want to be clear that we already see some troubling statements and findings in the report.  We will be following up on some of those statements via this blog, prior to publication of the comprehensive review.

Copies of the full report are available here (pdf):

https://www.portlandgeneral.com/-/media/public/corporate-responsibility/environmental-stewardship/water-quality-habitat-protection/deschutes/documents/deschutes-bmi-final-report.pdf?la=en

 

Unusual bloom of algae in March of 2016, approximately one mile below Pelton Reregulation Dam. Photo by Rick Hafele.

Unusual bloom of algae in March of 2016, approximately one mile below Pelton Reregulation Dam. Photo by Rick Hafele.

Greg McMillan and Larry Marxer taking water quality measurements in February, 2016. Photo by Andrew Dutterer.

Greg McMillan and Larry Marxer taking water quality measurements in February, 2016. Photo by Andrew Dutterer.

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Black Spot Disease Seen in Lower Deschutes River Fish

By Greg McMillan

We started receiving reports of “black spot” disease in lower Deschutes River bull trout a few weeks ago.  The first report was from Andrew Perrault from the Gorge Fly Shop in Hood River.  He sent along these photos and it is pretty easy to tell these black spots are not normal on bull trout.  Many of us know that bull trout are species Salvelinus and thus members of the char group.  These fish don’t have black spots as normal coloration.

Photo by Andrew Perrault.

Photo by Andrew Perrault.

Photo by Andrew Perrault.

Photo by Andrew Perrault.

Close up of lesions assumed to be due to black spot disease. Photo by Andrew Perrault.

Close up of lesions assumed to be due to black spot disease. Photo by Andrew Perrault.

Black spot disease on lower Deschutes River bull trout. Photo by Ryland Moore.

Black spot disease on lower Deschutes River bull trout. Photo by Ryland Moore.

Since that first report we’ve heard of other observations of black spot disease on both bull trout and red band trout.  The presence of black spot disease has been confirmed by sources at Oregon Department of Fish and Wildlife.

Black spot disease is caused by a flatworm (trematode) parasite known in the scientific community as Uvulifer ambloplitis, and also known as “neascus”.  This parasite has a complicated life cycle that starts with eggs in water, which hatch and become juveniles known as miracidia, which in turn infect aquatic snails.  In snails this form of the parasite matures into the next life form, known as cercariae.  Cercariae are shed by the snails and become free swimmers, which attach to fish.  Once the cercariae have attached to the flesh of fish, the fish develops an immune response that causes the dark spot.

Kingfishers are the next host, which become infected when they ingest infected fish.  The cercariae develop into adult flatworms.  The parasite then produces eggs, which are shed in feces by kingfishers, and deposited in water where the life cycle is reinitiated.

Black spot flatworm. Illustration by Bruce Worden.

Black spot flatworm. Illustration by Bruce Worden.

These flatworms do not appear to be fatal to fish, or other hosts.  There are scattered reports of fish stressed from other sources dying while infected.  No human infections have been reported, but there is no real surveillance mechanism to detect human infections.  Although probably safe for human consumption after thorough cooking, there are no study data to confirm that.

None of us who have fished the lower Deschutes River for decades can say that we’ve seen many, if any, fish with this condition.  There are reports indicating there have been infected fish in the lower Deschutes River and tributaries in the past, but they aren’t common.  So what has changed?  Is this random?  Or linked to the ongoing ecological changes we are all seeing in the lower river?

This might be related to an increase in the snail population in the lower Deschutes River.  Portland General Electric’s Year 1 Data Summary Report from their Lower Deschutes River Macroinvertebrate and Periphyton Report Study published in 2014, indicates that there has been a significant increase in snail populations in the lower Deschutes River.  This increase in population in the intermediate host (snails) might be related to the increase in black spot disease noted in fish.  The snail population increase is likely linked to the increase in algae in the lower river.

Is this a catastrophic occurrence?  Probably not.  But it could be another indication of ecological change in the lower Deschutes River.

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