Announcing the DRA 2016-2017 Macroinvertebrate Hatch Survey Report

Photo by Rick Hafele

The Deschutes River Alliance is pleased to present its 2016-2017 Macroinvertebrate Hatch Survey Report, prepared by Rick Hafele. As in previous years, this report describes survey data collected by lower Deschutes River fishing guides, documenting the presence and abundance of the major adult aquatic insect hatches on the lower river.

The survey data compiled in the DRA Hatch Survey Reports represent a systematic attempt to document changes in adult insect emergence timing and abundance on the lower Deschutes River. This data, submitted by highly experienced guides, provides the only ongoing assessment of changes to the lower river’s aquatic insect populations.

Here are some of the key takeaways from this year’s survey results and analysis:

  • As in previous years, survey results show that adult abundance of the four major orders of aquatic insects—mayflies, stoneflies, caddisflies, and Diptera (chironomids and crane flies)—is low from spring through fall. Percent of observations with high numbers of adults is rarely above 10% of all observations.
  • Emergence of all major hatches are occurring four to six weeks earlier than they did prior to the commencement of surface water withdrawal operations at Round Butte Dam.
  • The earlier emergence of these hatches is creating a period in the spring (typically early April through late May) when the vast majority of insect hatches now occur. After early- to mid-June insect hatches become scarce and unpredictable.
  • Many river users have reported that wildlife along the lower Deschutes River corridor that depend on aquatic insect adults (e.g. swallows, bats, nighthawks, and song birds) continue to show depressed numbers. This is mostly likely due to a lack of available food.

DRA believes that the above changes in adult insect timing and abundance can be directly linked to the changes in water quality—including higher nutrient loads and warmer water temperatures in the spring and early summer—resulting from selective water withdrawal operations at Round Butte Dam. The survey data summarized in this year’s report, along with reports from previous years, provide key information needed to fully understand the impact of recent changes in the lower Deschutes River.

Read the full report here.


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New Analysis Shows Significant Ecological Decline in Lower Deschutes River After Commencement of Selective Water Withdrawal Operations

Photo by Brian O’Keefe

In the years since Selective Water Withdrawal (SWW) operations began at the Pelton Round Butte Complex, longtime Deschutes River users have observed and reported what appear to be major ecological changes below the dams. A new report confirms these observations. A new analysis by Portland State University Assistant Professor Patrick Edwards, Ph.D., establishes that the macroinvertebrate community in the lower Deschutes River has significantly changed since surface water from Lake Billy Chinook began to be released through the SWW tower downstream into the lower river. According to Professor Edwards’ analysis, the post-SWW community contains “more non-insect taxa, such as worms and snails, and other taxa that are tolerant to poor stream conditions.” Further, there are now fewer “mayfly, stonefly and caddisfly taxa that are sensitive to poor stream conditions.”

Some background on Dr. Edwards’ study is useful. In April 2016, R2 Resource Consultants, a company under contract to Portland General Electric, released a Lower Deschutes River Macroinvertebrate and Periphyton Study. This was a four-year study, mandated by the Pelton Round Butte Project’s Clean Water Act certification, that aimed to compare post-SWW conditions in the lower Deschutes River to pre-SWW conditions that were documented in a baseline study.

Round Butte Dam and the Selective Water Withdrawal Tower.

The conclusions in the R2 study were perplexing. Among other findings, the authors stated that “[s]tudy results did not identify large changes in the macroinvertebrate community before and after SWW implementation.” The DRA Science Team, which had been following the development of this study closely, identified several problems with the final report, and in the following weeks worked with several outside experts to assess the data analysis and statistical methods used in the study.

Then, a few weeks after the R2 report was issued, the Oregon Department of Environmental Quality (ODEQ) stepped in. In a letter to PGE, ODEQ deemed the R2 report inadequate and deficient in several key components, and requested that PGE provide a response to correct the “serious shortcomings” in its analysis.

PGE responded to the ODEQ letter by stating that it would address the agency’s concerns and would summarize this additional work in an addendum to the original report—a process PGE estimated would take 6-12 months to complete. It now has been 19 months since that response letter was sent, and the promised addendum still has not issued.

In the same letter, PGE stated that despite its shortcomings, the initial report—which had already been submitted to the Federal Energy Regulatory Commission (FERC) —satisfied PGE’s obligations under the FERC license for macroinvertebrate monitoring. In other words, PGE claimed it had met its requirements with a report that ODEQ had identified as deficient in several respects.

We at the DRA felt it was essential that an accurate analysis of the pre- and post-SWW macroinvertebrate data be completed as quickly as possible. To that end, we contracted with Dr. Edwards to perform a thorough and accurate statistical analysis of the same data used in the R2 report. Dr. Edwards is highly qualified to perform this analysis, as his PhD in environmental science included extensive use of multivariate statistic—an analytical technique commonly used to assess changes in macroinvertebrate communities. The purpose of Dr. Edwards’ analysis was to assess the characteristics of the macroinvertebrate community pre- and post-SWW.

Photo by Brian O’Keefe.

The results of Dr. Edwards’ analysis are truly concerning. Data collected in the springtime showed that the post-SWW community has significantly fewer mayflies, stoneflies, and caddisflies—all species that are more sensitive to poor stream conditions. Data from both the spring and fall seasons showed an increase in taxa that are more tolerant to poor stream conditions, including worms and snails.

As a result of Dr. Edwards’ analysis, there is sound science confirming what many have suspected for years: SWW operations are significantly altering the ecology of the lower Deschutes River. The discharge of surface water from Lake Billy Chinook has caused serious, negative impacts to water quality in the lower river, and those impacts are leading to significant changes in the insect community below the dam complex. Negative changes to aquatic insects are a serious concern, as they support the entire food chain within the river, particularly resident trout, juvenile salmon and steelhead, and wildlife along the river – including birds and bats. Sound science establishes that these changes are statistically significant. DRA believes strongly that these changes can and must be reversed.

Presumably, if PGE’s initial analysis of this data had been sound, efforts in the intervening months and years could have been focused on addressing the ecological decline in the lower river. We certainly hope that work will commence, at long last, but we are proceeding with legal action to ensure no further delay.

For more information about Dr. Edwards’ analysis, read Rick Hafele’s summary of the report here.

To read the full report, click here.


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An Overview of Dr. Edwards’ Aquatic Invertebrate Study Analysis

By Rick Hafele

As recently reported, the DRA has just posted to its website a new report, by Dr. Patrick Edwards, that provides a detailed statistical analysis of the aquatic macroinvertebrates in the Deschutes River before and after the commencement of surface water releases from the Selective Water Withdrawal (SWW) tower at Round Butte Dam. Dr. Edwards’ report provides important confirmation that since the SWW Tower began operating, aquatic life in the lower Deschutes River (the 100 miles of river below the dams) has changed significantly for the worse.

Dr. Edwards’ report is actually a new analysis of data originally collected and analyzed for PGE by R2 Resource Consultants, as required under the Pelton Round Butte Project’s Clean Water Act certification. The R2 report and data were released to the public in April 2016. Unfortunately R2’s original analysis was flawed. As a result, the Oregon Department of Environmental Quality (ODEQ) requested that PGE have the data reanalyzed using proper methods. It has now been 19 months since that request by ODEQ, and PGE has yet to release a new analysis of the study.

To ensure that a new unbiased analysis would be completed, the DRA commissioned Dr. Edwards to reanalyze the data from the R2 study. To further ensure that the methods used by Dr. Edwards were correct and based on the best available statistical methods, the DRA had the report peer reviewed by one of the top environmental statisticians in the country.

While we invite all of our supporters to read the lower Deschutes River aquatic macroinvertebrate report by Dr. Edwards, the analysis relies on a number of complex statistical methods; unless you have a degree in statistics, it might leave you scratching your head. For that reason a less technical explanation of the analysis and its findings is provided here.

Photo by Rick Hafele

Why Aquatic Invertebrates and Algae?

            You might first wonder why aquatic macroinvertebrates (this includes all aquatic insects, as well as other invertebrates like snails and worms) and algae were the only aquatic life forms sampled to assess the possible impacts of surface water withdrawal on the ecology of the lower Deschutes River. Aren’t trout, steelhead, and salmon much more important as a recreational resource and commercial commodity? Certainly, fish outweigh invertebrates and algae in recreational and economic importance, but in terms of ecosystem health, if the organisms at the bottom of the food chain aren’t healthy and sustainable then the rest of the species further up the food chain will suffer.

There are several reasons why these lower food chain communities, especially aquatic invertebrates, are often closely examined in stream health studies.

  1. Aquatic invertebrates can be sampled more effectively and at less cost than fish. This is particularly true in a big river like the lower Deschutes. This doesn’t mean that fish studies in the lower Deschutes aren’t possible or shouldn’t be done but, to get a relatively quick and accurate assessment of possible impacts to the aquatic ecosystem, aquatic invertebrates are a good choice.
  2. Because the life cycle of aquatic invertebrates is much shorter than fish (one year or less for most invertebrates compared to four to six years for most salmonids) they will show a response to environmental changes much faster than will fish. This is critical if one wants to identify ecosystem problems as soon as possible.
  3. There is a long history within the study of stream ecology of sampling aquatic invertebrate populations to assess stream health and function. This means there are well-established methods for sampling and analyzing the data, and for interpreting the results. For example, when certain invertebrate populations thrive while others are lost or diminished, prior experience on other rivers can help us understand what is happening on the lower Deschutes.
  4. Last, the number of species of aquatic invertebrates found in Western rivers and streams is much greater than the diversity of fish, giving researchers a broader, more robust community of organisms to study. For example, invertebrate studies often collect more than 100 different species from a single Western stream, compared to 3-6 species of fish. In addition, the sensitivity of these different invertebrates to altered water quality and habitat conditions have been well documented for a wide range of species, and the sensitivity of different species to changes in water quality varies over a wide range. As a result, changes in the species composition of invertebrates provide a sensitive indicator of impacts to the biological health of streams and rivers. For example, decades of studies have shown that stoneflies are more sensitive to poor water quality than most other species. Therefore, a decline in their diversity or abundance is one of the first signs of declining stream health.

Photo by Rick Hafele.

Statistical Methods Used

            The purpose of Dr. Edwards’ study was to determine if the aquatic invertebrate community sampled after surface withdrawal began had changed in a statistically significant way from the community present before surface withdrawal. To make this determination, Dr. Edwards used three statistical methods:

  1. Multivariate ordinations
  2. A measure of species diversity
  3. A measure of species pollution tolerance

Multivariate ordinations:

Multivariate statistics is a powerful tool that you won’t find discussed in Statistics 101. This powerful and complex field of statistical analysis requires considerable experience to use and understand. Multivariate statistical methods like Non-metric Multi Dimensional Scaling (NMDS) are commonly used today partly because modern computing power makes it possible.

Basically, NMDS takes all 100+ invertebrate taxa from each sample and plots the relative abundance of each taxon in each sample in multidimensional space, and then compresses the multiple dimensions into a two-dimensional graph. The distance between dots on the plot indicate their degree of similarity; dots close together indicates a similar invertebrate community between samples, while dots farther apart indicates the communities present were different. Whether the distance between two groups of dots is statistically significant (meaning that the difference noted is very likely the result of actual differences and not due to random chance alone) is determined by performing other statistical tests.

The results of this analysis comparing the pre-tower to post-tower samples from the lower Deschutes River, showed that a statistically significant change occurred to the invertebrate community from the pre-tower to post-tower periods. What kind of change occurred is addressed with the other two analyses discussed below.

Measure of species diversity:

One of the most common measures of ecological or biological health is the diversity of species present. Healthy ecosystems are diverse ecosystems. In stream studies, healthier stream conditions are indicated by invertebrate communities with more species that are sensitive to poor water quality (higher temperature, lower dissolved oxygen or nutrient enrichment), relative to the number of species that are more tolerant of poor stream conditions. Mayflies, stoneflies, and caddisflies are the three groups of aquatic invertebrates with the most sensitive species to poor water quality. A decline in these sensitive species relative to species known to be more tolerant of degraded water is a sign that water quality is becoming degraded and constraining aquatic invertebrate populations. The metric EPTr refers to the percent of species of mayflies (E), stoneflies (P) and caddisflies (T) relative to the number of other species in the sample. In this study the metric EPTr was used to assess changes in the diversity of the sensitive taxa. The results show that at sites in the lower Deschutes River, EPTr declined in post-tower samples from pre-tower samples in both the spring and fall, and that the decline was statistically significant in the spring samples. A similar statistically significant decline was not observed at the three sites above the Round-Butte Dam Complex.

Measure of pollution tolerance:

As mentioned above, different species of aquatic invertebrates have different tolerance levels to water pollution. Years of researching the sensitivity of individual taxa to water quality conditions has produced a set of “tolerance” scores for each taxa. The metric used in this study is called RICHTOL, which calculates the mean tolerance score of all taxa present in a sample. Tolerance scores for individual taxa range from 0 to 10, with lower scores indicating more sensitivity to polluted water—species with these lower scores are more likely to decline in abundance as water quality declines. This analysis shows a statistically significant increase in the RICHTOL score in post-tower samples compared to pre-tower samples below the dam complex during both the spring and fall sample periods. An increase of this score indicates an increase in taxa present with greater tolerance to poor water quality, strongly suggesting that water quality has declined and this decline is having a negative affect on the aquatic invertebrate community. Again the sites above the dam complex did not show a similar significant increase in tolerant taxa.

Round Butte Dam and the Selective Water Withdrawal Tower.

Conclusions

  In summary, here are the principal findings from Dr. Edwards’ statistical analysis:

  1. A multivariate statistical analysis, comparing the complete invertebrate community in the lower Deschutes River from before tower operations to after tower operations, found that a statistically significant change in the community occurred.
  2. Comparing pre-tower samples to post-tower samples showed that a decline in the percent of sensitive species of mayflies, stoneflies, and caddisflies occurred at sites in the lower Deschutes River.
  3. A comparison of pre-tower to post-tower samples also found that taxa tolerant to poor water quality conditions increased significantly at sites in the lower Deschutes River below the dams, but no significant increase occurred at sites above the dams.

These results confirm: 1) a significant change has occurred to the macroinvertebrate community in the lower Deschutes River after tower operations and surface water releases began, and 2) a significant decline in pollution sensitive species (mayflies, stoneflies and caddisflies) and a significant increase in pollution tolerant species (primarily worms and snails) has occurred in the lower Deschutes River following surface water releases at the SWW tower.

Decades of stream studies have documented similar impacts due to nutrient enrichment and the resulting changes in water chemistry and algal communities. For example, as long ago as the early 1970s stream ecologists understood that large dams and reservoirs can impact waters downstream, as shown in the following quote from the seminal book on stream ecology, The Ecology of Running Waters, by H.B.N. Hynes:

The great photosynthetic activity in large impoundments has marked effects upon the chemistry of the water, raising pH and oxygen content and reducing the hardness of the water. The influence of a large dam is therefore profound and it extends a long way downstream.

             Anyone who has spent time on the lower Deschutes River after the SWW tower began operating knows there have been negative changes to water quality and the aquatic community. For example, if you have a house on the river, the simple fact that you no longer have to close your door at night to keep the bugs out when a porch light is on is a clear signal that something isn’t right. Observant anglers have seen crane fly numbers fall from very abundant to nearly non-existent. So why worry about statistics? Unfortunately those who might disagree with your porch light results or your onstream information on insect life may argue that your observations are anecdotal and don’t “prove” there is a biological impact from SWW operation. Such “proof” can be elusive, which is where the use of statistical analysis becomes important. The use of advanced statistical methods sets a standard for the level of confidence that the observed changes are real and not due to random variation.

Dr. Edwards’ analysis confirms what river users have been observing since the SWW tower began operating – the health of the river has declined. Fortunately, we know there is a simple way to reverse this decline in the river’s biological health: a significant increase in the amount of cooler, cleaner water discharged from the bottom of Lake Billy Chinook into the lower river.

For an introduction to Dr. Edwards’ report, click here.

To read the full report, click here:


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It’s the DRA’s Fourth Anniversary! Help Us Celebrate and Move Forward.

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Dear Deschutes River Alliance Supporter,

As a busy summer nears its end and we transition into fall, we would like to take a moment to reflect and to share our immense gratitude for your support and what it has helped us accomplish.

August has truly been a month for the books. In addition to our ongoing science work, we also celebrated a huge victory in our lawsuit against Portland General Electric. Last week, the U.S. Court of Appeals for the Ninth Circuit sided with DRA and refused to hear a PGE appeal that would have delayed this important lawsuit from moving forward. This decision also left in place a crucial ruling we secured this spring, affirming the rights of citizens to enforce water quality requirements at hydroelectric projects.

We are proud to say that this month also marks the four year anniversary of the official establishment of the Deschutes River Alliance as a 501(c)(3) nonprofit organization. Over the past four years, the DRA has worked tirelessly to restore cooler, cleaner water in the lower Deschutes River. Besides our important victories in the courtroom, the DRA Science Team has been diligently documenting the sources and extent of the ecological changes occurring in the lower river.

Of our many accomplishments in that time, here are a few we are particularly proud of:

  • A thermal imaging study of the lower Deschutes River and the area around the three dams of the Pelton-Round Butte Complex. This allowed us and others to have a better understanding of the temperature behavior of the river between the PRB Complex and the Columbia River.
  • Two years (and counting) of algae and water quality studies on Lake Billy Chinook and the lower Deschutes River. This work documents the changes in water quality that have occurred since selective water withdrawal operations began, including the water quality violations that are at the core of our lawsuit against PGE.
  • Three years (and counting) of our annual adult aquatic insect hatch survey. This survey was designed by DRA Board member and renowned aquatic entomologist Rick Hafele, to gather data on hatch timing and densities.
  • Over one year of benthic aquatic insect sampling in two locations in the lower river, to document trends in subsurface aquatic insect activity. This study, along with the hatch survey results, indicates an increase in worms and snails along the river’s bottom, and a decrease in adult aquatic insect populations in the air.
  • Funded a GIS mapping project of water quality in the lower Crooked River, to better understand the source of the pollution load entering Lake Billy Chinook.
This and more have been achieved over the last four years. None of this could have been achieved without the dedication of people like you. You are what keep us on the water and in the courtroom fighting to restore the river we all love.

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Our mission continues to drum in our ears. It beats stronger with each day. As the river grows quieter, our voices grow louder.

Take a moment to listen to board member and key science team leader, Rick Hafele, as he masterfully recounts the abundance of activity that once filled the Deschutes River.

“Song for the Deschutes”
-Rick Hafele



This is where we stand. As we enter our fifth year, we are proud to take with us many victories, but the final battle has not yet been won. After our critical legal victory this month, we are entering a new stage of our Clean Water Act lawsuit against Portland General Electric. Now more than ever, we need your help in our fight to protect and restore this spectacular river.

Many of you have a long history on the Deschutes. All of you have at least one story to tell of time spent by or in its waters. If you have been to the Deschutes this summer, you are likely walking away with a different tone to the story of your day. Maybe instead of catching steelhead, you hooked bass or walleye. Maybe you noticed the failure of caddis hatches to materialize in the evening.  Maybe you left without the sounds of songbirds or the cloud of insects trailing behind you.

Rest assured that this fight is not over. We can revive the once vibrant display of the Deschutes River that you’ve long known. Thank you for your support over the past four years, and cheers to Year Five: may it be the loudest ever.

 


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Oregon Department of Environmental Quality Notifies Portland General Electric of “Serious Shortcomings” in R2 Resource Consultants Report on Insects and Algae in Lower Deschutes River

Round Butte Dam and the Selective Water Withdrawal Tower. Photo by Greg McMillan.

Round Butte Dam and the Selective Water Withdrawal Tower. Photo by Greg McMillan.

Citing flawed laboratory methodology and inappropriately applied statistical analysis, the Oregon Department of Environmental Quality (ODEQ) informed Portland General Electric (PGE) in a May 23, 2016 letter that PGE’s report by R2 Resource Consultants has been deemed inadequate and deficient in several key components.

The primary purpose of the R2 Resource Consultants study, titled “Final Report: Lower Deschutes River Macroinvertebrate and Periphyton Study” and mandated by the dam operators’ Clean Water Act Section 401 Water Quality Certification, is to determine whether or not operation of the Selective Water Withdrawal Tower at Round Butte Dam has had an impact on the ecology of the river below the dam complex. A baseline study was done in 1999-2001. The present study was intended to compare current in-river conditions in the lower Deschutes River to prior conditions as they were documented in the baseline study.

ODEQ has given PGE until June 30, 2016 to “respond with a plan for mitigating or eliminating the shortcomings of the study.”

As a result, the study’s conclusion that water quality and overall health has improved in the lower river has been rendered an assertion without scientific support. The ODEQ review even went on to say that there are indications that the study supports the opposite conclusion and that water quality has been reduced.

The ODEQ review of the study also expressed the same concern that the DRA had previously described regarding the collection of water quality data and the suggestion by the authors that unfavorable water quality results in the report were due to poorly calibrated instruments.

DRA Analysis of the Report

The DRA had asked four highly qualified individuals (each has a PhD in a field specific to the R2 report) to critique the study. We recently received the first of those critiques back. It is critical of the statistical methodology employed by R2 Resource Consultants and confirms ODEQ’s analysis.

We sought these four reviews as we had major concerns about the R2 report. Almost all of our concerns are mirrored in the ODEQ analysis.

The Selective Water Withdrawal Tower above Round Butte Dam. Photo by Greg McMillan.

The Selective Water Withdrawal Tower above Round Butte Dam. Photo by Greg McMillan.

How Did This Happen?

The macroinvertebrate and periphyton study is a highly important component of the monitoring of the Pelton-Round Hydroelectric Complex impact on the Deschutes River. The installation and implementation of the Selective Water Withdrawal Tower was the single largest anthropogenic change that has been imposed on the lower Deschutes River in the past fifty years. The impacts of that change have to be monitored effectively using appropriate methodology and analysis. This sort of monitoring is mandated by the Water Quality Management and Monitoring Plan, a part of the Clean Water Act Section 401 Certification that sets standards for operations at the Pelton-Round Butte Hydroelectric Complex.

This is the only way to determine if tower operations are having harmful effects on the lower river.

The dam operation permits and certification call for “adaptive management” in the event that there are problems created by Selective Water Withdrawal. To date, the only “adaptive management” invoked by PGE has been to seek agreements from ODEQ not to enforce various water quality requirements imposed on dam operations. The intent of the macroinvertebrate and periphyton study is to determine if that has or has not resulted in damage to the ecology of the lower river.

So the stakes are high for PGE. If this report were to document a decline in water quality and unfavorable changes to the ecology of the river below the dam complex, changes in dam operations would need to be made.

R2 Resource Consultants seem to be highly qualified to conduct studies such as this. But the work was done as a paid service to PGE.

PGE has been entrusted with the responsibility of monitoring for adverse changes to the river system as a consequence of the SWW Tower and its operation. This responsibility needs to be undertaken with a rigorous and transparent approach to assessing the state of a public resource affected by their operations. Anything else is a violation of that responsibility.

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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.

Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River. 

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A Second Type of Algae Plagues the Lower Deschutes

By Greg McMillan and the Board of Directors of the Deschutes River Alliance, to especially include Cam Groner and Rick Hafele

In the words of DRA board member John Hazel, “It’s been a rugged summer.”  He’s right.  Drought, fire, smoke, warm water temperatures, fish die-offs, and fishing closures have all plagued the lower Deschutes River this year.  Now we have a new problem.  As if the lower Deschutes hasn’t had enough problems already.

Starting two weeks ago we started receiving emails and phone calls about a free-floating, green filamentous algae being present in the river.  It was draping itself in clumps over flies, knots in fishing lines, lures, side-planers and anchor lines on boats.  Shortly after that we started hearing from individuals with pumps in the river for domestic and irrigation withdrawals.  The algae was clogging the screens on their pumps.  Next we heard that the water pump at the fish counting station at Sherars Falls was suffering from the same problem with clogged screens.   The impact to irrigation pumps has resulted in screens having to be cleaned several times a day.  This puts very expensive pumps at risk of serious damage.

The potential economic consequences of this are hard to estimate, but it does have an impact.  Anglers are already avoiding the lower Deschutes due to warm water, a slippery river bottom, lack of aquatic insect hatches and turbidity from White River.  This impacts guides, outfitters and other businesses dependent upon the angling economy.

For those with pumps in the river, the cost of a damaged pump, labor to clean screens, or an outright inability to irrigate would be damaging to their incomes.  These incomes pay the tax dollars that support Wasco County and the Maupin School District.

The Algae

These stringy looking dark green algae have been presumptively identified as Cladophora, with possibly some Anabaena mixed in.  Cladophora has been observed in the lower Deschutes River for a long time.  But never in quantities like are being observed now.

The peak time for growth of Cladophora is typically late spring and early summer, although it can undergo a growth spurt in fall as decomposing organic matter provides nutrients to stimulate its biological activity.

Cladophora is widespread globally.  Cladophora blooms in the Great Lakes are legendarily bad and have created major environmental problems including fish die-offs.  This happens when the Cladophora dies and starts to decay, using up oxygen in the water and creating low oxygen conditions for fish and other aquatic organisms.  We are not likely to see fish die-offs due to Cladophora in the lower Deschutes as long as the flowing water in the river helps keep oxygen at adequate levels.

The growth of Cladophora has probably reached its peak in the lower Deschutes River, as well as its maximum life expectancy.  It is now detaching from the substrate in the river and floating off in the current for the last of its short life.

Cladophora sample collected from the lower Deschutes River on August, 16, 2015. Photo by Greg McMillan.

Cladophora sample collected from the lower Deschutes River on August, 16, 2015. Photo by Greg McMillan.

Why So Much Cladophora Now?

Cladophora blooms like we are seeing in the lower Deschutes River are invariably the consequence of an increased nutrient load in the river.  The nutrients are nitrogen and phosphorous.  Warm water helps fuel the growth of Cladophora.

This summer has been very warm, even downright hot at times.  Temperature management at the Pelton-Round Butte Dam Complex has used large amounts of surface water to increase dam discharge water temperatures in accordance with the Without Project Temperature (WPT, and previously called Natural Thermal Potential) model utilized by the dam owner/operators (Portland General Electric and The Confederated Tribes of the Warm Springs Reservation). In a recent blog post we described how this model works and how it results in the harmful warming of the lower river during times of warmer air temperatures.

During our fieldwork in Lake Billy Chinook this year, we’ve been seeking to determine how dam operations have altered the nutrient load in the lower Deschutes.  We’ve found that of the three tributaries, the Crooked River has the highest nutrient load, while the Metolius River has the lowest.  The Metolius, in our sampling, has had no detectable nitrogen based nutrients.

The Metolius River enters the reservoir and then flows into the forebay of the dam at depths approaching 350 feet.  The Crooked River enters the forebay at about 120 feet of depth (the Middle Deschutes enters the Crooked River Arm about ½ mile south of the forebay).  The result is that the combined Crooked and Middle Deschutes River water sits on top of the Metolius River water during warm months.  Once the lake cools in mid- to late fall, the lake begins to “turn over” or mix.

The consequence of this is that the surface water in the forebay consists primarily of Crooked River water.  To see how the nutrient load in the Crooked River water fuels algae growth, take a look at the surface water in the Crooked River Arm of the reservoir in this unaltered photo:

Photo by Greg McMillan.

Photo by Greg McMillan.

Here is what the surface water looks like in the forebay of Round Butte Dam during summer:

Photo by Greg McMillan.

Photo by Greg McMillan.

By mid-summer the algae in the reservoir have used much of the nutrients for their own growth, but through spring and early summer that nutrient laden water is discharged into the lower river.   The result is more rapid algal growth.  And not just with Cladophora, but also with the stalked diatoms we’ve been documenting in the lower river that have contributed to the decline of aquatic insects.

Prior to the completion of the Surface Water Withdrawal Tower at Round Butte Dam in 2009, Metolius River water made up the bulk of the water drawn from the reservoir for power production.  We didn’t have these problems in the lower river prior to operation of the SWW Tower.

We are certain that these consequences of surface water withdrawal were not intended in the design and implementation of the Selective Water Withdrawal program that attempted to provide currents in the reservoir for juvenile fish migration.

The Solution

It has been demonstrated in cases of other Cladophora blooms that controlling nutrient load reduces or eliminates the problem.  That can be done in this case.  And should be done by reducing the amount of warm, nutrient-laden surface water being discharged into the lower Deschutes.  Nuisance algae problems have been increasing annually since the initiation of surface water withdrawal at Round Butte Dam.

We need to develop the political will to push PGE to alter dam operations in a fashion that eliminates the nutrient loading of the lower Deschutes River.  This is possible now with the adaptive management language in the dam operating license.

We also need the Oregon Department of Environmental Quality to stop ignoring the ongoing violations of water quality standards in the lower Deschutes River.  This will require in-depth water quality studies that could take years to get done.  So it needs to start now.  This is the long-term remedy to the algae problems in the lower Deschutes River.

Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River. 

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