We are pleased to announce the release of the DRA’s latest water quality report. The report is an analysis of water quality in the lower Deschutes River in 2019. This monitoring continues to be an important element in our science program and provides invaluable insight into changes occurring on the river. What did we find?
Selective water withdrawal continues to result in exceedances to the Deschutes Basin water quality standards:
• Water temperature exceeded the state water quality standard during the period designated for salmon and steelhead spawning.
• Dissolved oxygen concentration is not being managed to adequately protect incubating trout eggs and fry.
• Excessively high pH levels above the state water quality standard occurred and large diel swings were recorded. Large diel swings in pH and dissolved oxygen are an indicator of excess nutrients in the water leading to high amounts of algae and aquatic plant biomass.
Some interesting changes were observed in 2019 compared to prior years’ results. These findings are detailed and substantiated in our annual water quality report (link to report). While any positive changes are welcome news, Oregon’s water quality standards are still not being met. Absent effective action by state and federal authorities, the DRA will continue to seek enforcement of the Clean Water Act water quality standards as a principle means of improving water quality in the lower Deschutes River.
We want to give our most heartfelt thanks to our supporters for making it possible to do this work. These challenging times are affecting all of us. Despite the challenges ahead we will continue to work toward our mission. Thank you for your support in defending the lower Deschutes River.
In March 2020 the DRA attended the Oregon chapter of the American Fisheries Society Annual Meeting in Bend, Oregon. We presented a poster with the results of our benthic sampling study in the lower Deschutes River and the implications for fish. Our poster was well received. The feedback from attendees was that the Deschutes River Alliance’s monitoring efforts are important and should continue.
Photo Caption: Non-insect abundance and their contributions to salmonid parasites in the Deschuts River, OR poster. Benthic sampling data was collected and analyzed by the DRA and our poster was presented at the Oregon chapter of the American Fisheries Society Annual Meeting on March 4, 2020. (Find the poster here)
The results of our analysis showed an alarmingly high abundance of polychaete worms and snails and included the following key findings:
Polychaete worms host a parasite called Ceratonova shasta that is often lethal for fish. Declines in returning adult Chinook salmon in the Klamath River are attributed to the C. shasta parasite.
Snails host a worm-like fluke parasite that causes black spot disease in fish.
Non-insects accounted for >50% of the total abundance in all samples.
We believe the simplest explanation for these results are the declines in water quality that we’ve seen in the lower Deschutes River as a result of Selective Water Withdrawal Tower passing warm, nutrient rich surface waters from Lake Billy Chinook into the lower Deschutes River. These findings highlight the urgency for immediate improvements in water quality. Increased nutrient loads combined with warmer water temperature in the winter through early summer has led to nuisance levels of algae and aquatic plant growth since surface water withdrawal began at the Tower in Lake Billy Chinook.
Cooler water temperatures will help ameliorate the effects of these parasites. Improvements to water quality (i.e., reductions in nutrient concentrations and meeting Oregon’s water quality standards) can restore the robust and healthy insect communities of mayflies, caddisflies, and stoneflies. Oregon’s water quality standards were set to protect the beneficial uses of streams including supporting aquatic life. We will continue to advocate for the managers of the Tower to reduce water temperature and meet state water quality standards to the maximum extent possible as the most immediate solution to restore the lower Deschutes River. Read DRA’s recently published position statement on all the issues here (link).
The Deschutes River Alliance is pleased to present its 2019 Hatch Survey Report. 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. The data, submitted by highly experienced guides and anglers, 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—stoneflies, caddisflies, mayflies, and Diptera—is low from spring through fall. A majority of surveys reported “none” observed.
Shifts in hatch timing were also observed, particularly for the pale morning dun mayfly, salmonfly, and golden stone. Salmonflies and golden stones have consistently emerged four to five weeks earlier than they did prior to the commencement of surface water withdrawal operations at Round Butte Dam.
Adult hatches for the salmonfly and golden stone showed slight improvement compared to prior years. About 30% of surveys reported “high” abundance for salmonfly and golden stone in 2019 compared to 8% for salmonflies and 20% for golden stones in 2017.
Hatches of Diptera (chironomids and crane flies) remain low. However, some recovery of the crane fly occurred, with 21% of surveys that reported low and moderate abundance and 1% reported high abundance in 2019.
Changes in seasonal water temperature and annual water quality as a result of the Selective Water Withdrawal Tower have led to changes in the abundance and emergence timing of aquatic insects in the lower Deschutes River.
Despite all the challenges we are facing in this era of the Coronavirus epidemic, the DRA is continuing to advance our mission. Thank you to everyone who has reached out about the impact of the virus on your lives, families, communities and businesses. We continue to be grateful for your ongoing support of the DRA and the lower Deschutes River. Please stay safe during this time and we look forward to gathering with you again soon as we continue our fight to return clean, cooler water to the lower Deschutes River.