U. S. Geological Survey
Bureau of Reclamation
Yakama Nation Fisheries
Washington Department of Fish and Wildlife
A study was conducted during June–October 2020 to evaluate factors affecting the migration success of adult sockeye salmon (
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Yakama Nation Fisheries provided labor, fish transport, and tagging support during the study. We also appreciate the efforts of Alan Butler, John Butenhoff, Ken Baird, Robert Brigantic, Greg Couch, David Dalan, Jacob Dalan, Joe Jancovic, Jeff Jones, Eric McCrea, John Merk, Phil Moytka, Craig Nelson, Thor Ostrom, George Pressler, Jack Ramynke, Jason Ramynke, Marggie Ramynke, Greg Reault, Spencer Reiboldt, Tony Reiboldt, Teddy Schmitt, Cory Scott, Barry Shoemake, Jay Southwick, and Chris Tanahill, who served as volunteer anglers to collect adult sockeye salmon that were tagged and released at the Yakima River mouth. The Washington State Department of Ecology was a partner on this study, and we appreciate their involvement.
We thank Brian Ekstrom, Philip Haner, Gabriel Hansen, and Ryan Tomka of the U.S. Geological Survey for their field efforts.
Multiply | By | To obtain | ||
Length | ||||
---|---|---|---|---|
centimeter (cm) | 0.3937 | inch (in.) | ||
millimeter (mm) | 0.03937 | inch (in.) | ||
meter (m) | 3.281 | foot (ft) | ||
kilometer (km) | 0.6214 | mile (mi) | ||
meter (m) | 1.094 | yard (yd) | ||
Volume | ||||
liter (L) | 33.81402 | ounce, fluid (fl. oz) | ||
Flow rate | ||||
cubic foot per second (ft3/s) | 0.02832 | cubic meter per second (m3/s) |
Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:
°F = (1.8 × °C) + 32.
passive integrated transponder
river kilometer
Bureau of Reclamation
U.S. Geological Survey
The Yakima River, in Washington State, historically supported the largest run of sockeye salmon (
In 2002, as part of a settlement agreement with the Yakama Nation, the Bureau of Reclamation (Reclamation) agreed to evaluate the feasibility of constructing fish passage structures at five reservoir dams in the Yakima Basin, eventually determining that this was feasible (
Table 1. Number of adult sockeye salmon returning annually to Prosser and Roza Dams, Yakima River, Washington, 2013–20
Year | Number of fish at Prosser Dam | Number of fish at Roza Dam |
2013 | 696 | 691 |
2014 | 2,678 | 2,576 |
2015 | 342 | 95 |
2016 | 3,742 | 3,949 |
---|---|---|
2017 | 372 | 137 |
2018 | 456 | 201 |
2019 | 110 | 201 |
2020 | 2,549 | 4,379 |
Adult sockeye salmon pass McNary Dam (located 69 river kilometers [rkm] downstream from the Yakima River mouth) during June–August (
Daily percentage of the total run of adult sockeye salmon passing Prosser Dam in the Yakima River (light-blue bars) and McNary Dam on the Columbia River (solid red line), and daily water temperature on the Yakima (dashed blue line) and Columbia (black dotted line) Rivers, Washington, June–October 2013–20. Horizontal gray line at 20 degrees Celsius is included for reference.
Figure 1. Graphs showing daily percentage of the total run of adult sockeye salmon passing Prosser Dam in the Yakima River and McNary Dam on the Columbia River, and daily water temperature on the Yakima and Columbia Rivers, Washington, June–October 2013–20
Although elevated summer water temperature is a threat to adult sockeye salmon in the lower Yakima River, research by
A telemetry study was conducted during June–October 2020 to evaluate factors affecting migration of adult sockeye salmon in the Yakima River. This study follows a pilot study conducted during 2019 that included radio-tagging of 60 adult sockeye salmon released in the lower Yakima River and at the mouth of the Yakima River mouth in June and July (
Adult sockeye salmon were collected, tagged, and released at two locations during the study. A total of 26 fish were collected and tagged with a radio transmitter and PIT tag at Prosser Dam from June 19 to June 22, 2020. One-half of the tagged fish (13 fish) were released into the forebay of Prosser Dam to resume upstream migration in the Yakima River. The remaining 13 fish were transported downstream by truck and released at the mouth of the Yakima River to collect information on fish behavior downstream from Prosser Dam (
Table 2. Number of adult sockeye salmon collected and tagged on the lower Yakima River, Washington, 2020
[
Collection location | Tagging date | Prosser Dam | Yakima River mouth | ||||||
---|---|---|---|---|---|---|---|---|---|
RT+PIT |
FL range |
RT+PIT |
FL range |
PIT only |
FL range |
||||
Prosser Dam | June 19, 2020 | 2 | 47–49 | 2 | 48–50 | NA | NA | ||
Prosser Dam | June 20, 2020 | 9 | 41–53 | 9 | 45–49 | NA | NA | ||
Prosser Dam | June 22, 2020 | 2 | 48–53 | 2 | 47–49 | NA | NA | ||
Yakima River mouth | June 26, 2020 | NA | NA | NA | NA | 12 | 46–52 | ||
Yakima River mouth | July 17, 2020 | NA | NA | NA | NA | 38 | 44–52 | ||
Yakima River mouth | August 7, 2020 | NA | NA | 6 | 49–55 | 62 | 45–56 | ||
13 | 41–53 | 19 | 45–55 | 112 | 44–56 |
Locations of fish release sites (black arrows) and fixed radio telemetry monitoring sites (black closed diamonds) used to detect tagged fish in the Yakima and Columbia Rivers, Washington. Image is the intellectual property of Esri and is used herein under license. Copyright © 2021 Esri and its licensors. All rights reserved. Hwy, Highway; I-182, Interstate Highway 182.
Figure 2. Image showing locations of fish release sites and fixed radio telemetry monitoring sites used to detect tagged fish in the Yakima and Columbia Rivers, Washington
Fish collected at Prosser Dam were trapped in the southernmost fish ladder (river right bank) at the dam. To operate the fish trap, a weir was lowered into the fish ladder to prevent fish from moving upstream past the weir and water was diverted from the ladder through a steeppass that had an entrance located immediately downstream from the weir. To enter the trap, fish moved upstream through the steeppass and fell about 1 meter (m) into the wetted trap where they remained until tagging occurred. The trap was checked once per day at about 8:00 a.m. Fish tagged on June 19 and 20 were collected over approximately 24 hours whereas fish tagged on June 22 were collected over approximately 48 hours. Fish were hand netted from the trap and transferred to a 378-liter (L) holding tank that contained fresh river water. Each fish was measured to the nearest centimeter for fork length, sex was visually estimated, PIT tags were implanted into the pelvic girdle, and a radio transmitter (Lotek Wireless; Model MCFT3–EM-T-L®; Newmarket, Ontario, Canada) was implanted gastrically using methods described in
Angling was used to collect fish at the mouth of the Yakima River. The Washington Department of Fish and Wildlife organized a group of volunteer anglers to collect fish for tagging on three days (June 26, July 17, and August 7, 2020). On each day, a total of 26 anglers fished on six boats from about 5:00 a.m. until 10:00 a.m. The tagging crew operated a seventh boat that remained close to the angling boats. The tagging crew monitored the angling boats continuously and when fish were caught, pulled alongside individual boats to transfer fish to a 378-L holding tank filled with fresh river water. Each fish was tagged with a PIT tag, measured to the nearest centimeter for fork length, and its sex was visually estimated. Six of these fish also were tagged with a radio transmitter on August 7, 2020, using methods described earlier in this section. Tagged fish were released near the point of capture as soon as they appeared to be visibly recovered from the collection and tagging process.
A total of 11 fixed monitoring sites were established to detect tagged fish moving within the study area. All monitoring sites contained radio telemetry equipment and were located downstream from Roza Dam on the Yakima River and downstream from Priest Rapids Dam on the Columbia River (
Mobile tracking was conducted to collect additional information on the location of tagged fish in the study area between fixed sites. A vehicle was used to slowly drive along the river, where feasible, while monitoring for the presence of tagged fish. In the lower Yakima River and Columbia River, a boat was used to conduct mobile tracking. When a tagged fish was observed, the date, time, and coordinates (latitude and longitude) of the detection location were recorded. Mobile tracking was conducted 3–4 times per month during the study period. If the mobile tracking crew encountered a tag that was not moving, they attempted to locate the tag to determine the fate of the fish. A final effort to locate and recover tags in the Yakima River was attempted at the end of the study period.
Detection records from fixed monitoring sites were merged with tagging and release records to create a preliminary dataset. The preliminary dataset then was integrated with mobile tracking records to create a draft dataset that was proofed using an automated program to remove non-valid detection records. Records were determined to be non-valid if (1) they occurred prior to release, (2) the signal strength was less than the 90th percentile of the signal strength of detections of tag identification codes that were not released during the study (noise), (3) less than three consecutive detections occurred at a given monitoring station (consecutive detections had to be 60 seconds or less apart), and (4) it was impossible for the detection to occur geographically (for example, detections at separate locations with timestamps that would have exceeded the swimming capability of the fish). These criteria were used in the automated program to remove non-valid detection records from the dataset containing detections of study fish. The auto-proofed dataset then was manually reviewed to confirm that the auto-proofing process was successful and to verify that the dataset could be considered final for analysis. This final dataset was used for all data queries and analyses presented in this report.
We used data collected at existing streamgages in the Yakima River to describe water temperature and river flow patterns during the study. Daily water temperature data from the U.S. Geological Survey (USGS) streamgage located on the Yakima River at the Van Giesen Bridge in Richland, Washington (about rkm 13.5; USGS streamgage 12511800) were downloaded for the June 1, 2020–October 1, 2020 time period from the following site:
We examined the final dataset to describe the behavior of tagged fish and movements using six reaches of the study area (
Table 3. Study reach descriptions used in this report
Reach name | Reach description |
Downstream from McNary Dam | Columbia River, downstream from McNary Dam. |
McNary Dam to Yakima River mouth | Columbia River, from the forebay of McNary Dam to the Yakima River mouth. |
Snake River | Snake River, upstream from Ice Harbor Dam. |
Yakima River | Yakima River, upstream from the Yakima River mouth. |
Hanford Reach | Columbia River, from the mouth of the Yakima River to the tailrace of Priest Rapids Dam. |
Upstream from Priest Rapids Dam | Columbia River, upstream from Priest Rapids Dam. |
Tagging and detection history data of PIT-tagged adult sockeye released in the Columbia River Basin were downloaded from the PTAGIS website (
Water temperature in the lower Yakima River exceeded 20 °C most days from mid-June to early September and peaked at 28 °C on July 31, 2020 (
Sockeye salmon tagging dates (red vertical lines), mean daily river flow in the Yakima River (light blue line), mean daily water temperature in the lower Yakima River (dark blue line), and mean daily water temperature in the Columbia River (black dotted line) near Richland, Washington, June 1–October 1, 2020.
Figure 3. Graph showing sockeye salmon tagging dates, mean daily river flow in the Yakima River, mean daily water temperature in the lower Yakima River, and mean daily water temperature in the Columbia River near Richland, Washington, June 1–October 1, 2020
Radio-tagged sockeye salmon released in the forebay of Prosser Dam initially moved upstream and spread out in the Prosser Dam-to-Sunnyside Dam reach. A total of six tagged fish (46 percent) were detected at Marion Drain and two fish (15 percent) were detected at Sunnyside Dam. However, all fish stopped moving within 2 weeks of release and several transmitters were recovered in the Prosser Dam-to-Sunnyside Dam reach. Thermal history data from those transmitters were plotted along with Columbia River and Yakima River water temperature and detection events (app. l,
Sixteen of the 19 radio-tagged sockeye salmon released at the mouth of the Yakima River were detected at radiotelemetry or PIT-tag monitoring sites. Of those 16 fish, two fish were detected downstream from McNary Dam, four fish were detected between McNary Dam and the mouth of the Yakima River, two fish were detected in the Yakima River, 15 fish were detected in the Hanford Reach, and two fish were detected upstream from Priest Rapids Dam. Of the fish that moved upstream to the Hanford Reach, all were detected at the Johnson Island site within 1–4 days after tagging. Twelve of those fish made multiple trips to Johnson Island and two were detected at Priest Rapids Dam. One of the fish detected at Priest Rapids Dam eventually moved upstream and was detected at Rock Island Dam.
The last known locations of radio-tagged fish included two fish downstream from McNary Dam in John Day Reservoir, two fish in the Yakima River, two fish near the mouth of the Yakima River, nine fish in the Hanford Reach, and one fish upstream from Priest Rapids Dam (
Table 4. Final locations of radio- and passive integrated transponder-tagged adult sockeye by release month after collection and release at the mouth of the Yakima River, Washington, 2020
[
Detection history | June | July | August | Combined | |||||||
PIT |
Total |
PIT |
Total |
RT+PIT | PIT |
Total |
Total |
||||
Downstream from McNary Dam | 0 | 0 (0) | 1 | 1 (3) | 0 | 0 | 0 (0) | 1 (1) | |||
McNary Dam to Yakima River mouth | 0 | 0 (0) | 0 | 0 (0) | 1 | 1 | 2 (3) | 2 (2) | |||
Snake River | 0 | 0 (0) | 0 | 0 (0) | 0 | 0 | 0 (0) | 0 (0) | |||
Yakima River | 6 | 6 (50) | 11 | 11 (29) | 2 | 24 | 26 (38) | 43 (36) | |||
Hanford Reach | 0 | 0 (0) | 1 | 1 (3) | 1 | 1 | 2 (3) | 3 (2) | |||
Upstream from Priest Rapids Dam | 2 | 2 (17) | 7 | 7 (18) | 1 | 5 | 6 (9) | 15 (13) | |||
Avian predation | 0 | 0 (0) | 1 | 1 (3) | 0 | 1 | 1 (1) | 2 (2) | |||
Not detected | 4 | 4 (33) | 17 | 17 (44) | 1 | 31 | 31 (46) | 52 (44) | |||
12 | 12 (100) | 38 | 38 (100) | 6 | 68 | 68 (100) | 118 (100) |
Water temperature use data (thick black line) collected by a radio transmitter inside an adult sockeye salmon (fork length 48 centimeters) released at the mouth of the Yakima River on June 20, 2020. The fish was harvested in John Day Reservoir on July 8, 2020. Black text boxes identify times and locations of detection in the study area. Water temperature data from the Columbia River (blue line; streamgage PAQW, Pasco, Washington) and Yakima River (red line; streamgage CFSW; Chandler Fish Screens) are included for reference. PIT, passive integrated transponder.
Figure 4. Graph showing water temperature use data collected by a radio transmitter inside an adult sockeye salmon released at the mouth of the Yakima River on June 20, 2020
Mean daily water temperature as measured at the Van Giesen Bridge (U.S. Geological Survey streamgage 12511800) in Richland, and number of radio-tagged sockeye salmon that entered the Yakima River and were detected on a fixed site, Washington, 2020.
Figure 5. Graph showing mean daily water temperature as measured at the Van Giesen Bridge in Richland, and number of radio-tagged sockeye salmon that entered the Yakima River and were detected on a fixed site, Washington, 2020
Water temperature use data (thick black line) collected by a radio transmitter inside an adult sockeye salmon (fork length 49 centimeters) released at the mouth of the Yakima River on August 7, 2020. The transmitter was recovered near Sunnyside Dam on October 26, 2020. Black text boxes identify times and locations of detection in the study area. Water temperature data from the Columbia River (blue line; streamgage PAQW, Pasco, Washington) and Yakima River (red line; streamgage CFSW; Chandler Fish Screens) are included for reference. CR, Creek; PIT, passive integrated transponder.
Figure 6. Graph showing water temperature use data collected by a radio transmitter inside an adult sockeye salmon (fork length 49 centimeters) released at the mouth of the Yakima River on August 7, 2020
Water temperature use data (thick black line) collected by a radio transmitter inside an adult sockeye salmon (fork length 53 centimeters) released at the mouth of the Yakima River on August 7, 2020. The transmitter was recovered near Benton City, Washington, on October 22, 2020. Black text boxes identify times and locations of detection in the study area. Water temperature data from the Columbia River (blue line; streamgage PAQW, Pasco, Washington) and Yakima River (red line; streamgage CFSW; Chandler Fish Screens) are included for reference. CR, Creek.
Figure 7. Graph showing water temperature use data collected by a radio transmitter inside an adult sockeye salmon (fork length 53 centimeters) released at the mouth of the Yakima River on August 7, 2020
Detection records were plotted to show the relation between diel arrival period (daytime versus nighttime) and residence time at fixed telemetry sites within the study area (
Residence time by diel arrival period for radio-tagged adult sockeye salmon at fixed telemetry sites on the lower Yakima River, Washington, 2019–20. Diel period is defined by civil twilight and potential cool water sites are shaded gray. Multiple trips of fish are included, and total number of trips are shown below the data points for each site.
Figure 8. Graph showing residence time by diel arrival period for radio-tagged adult sockeye salmon at fixed telemetry sites on the lower Yakima River, Washington, 2019–20
A total of 112 adult sockeye salmon were PIT-tagged and released at the mouth of Yakima River in June (12 fish), July (38 fish), and August (62 fish) 2020. Sixty-one (54 percent) of the PIT-tagged sockeye salmon eventually were detected on PIT-tag antennas in the Yakima, Columbia, and Snake Rivers (
Table 5. Detection history of passive integrated transponder-tagged adult sockeye salmon released at the mouth of the Yakima River in river reaches by chronological detection history and release month, Washington, 2020.
[
Detection history | Number of fish detected | |||
June | July | August | Total | |
Avian predation | 0 | 1 | 1 | 2 |
McNary Dam to Yakima River mouth to downstream from McNary Dam | 0 | 1 | 0 | 1 |
McNary Dam to Yakima River mouth to the main-stem Yakima River | 0 | 0 | 1 | 1 |
McNary Dam to Yakima River mouth | 0 | 0 | 1 | 1 |
Yakima River | 6 | 11 | 23 | 40 |
Hanford Reach | 0 | 1 | 1 | 2 |
Upstream from Priest Rapids Dam to the Snake River to upstream from Priest Rapids Dam | 0 | 1 | 0 | 1 |
Upstream from Priest Rapids Dam | 2 | 6 | 5 | 13 |
No detection | 4 | 17 | 30 | 51 |
12 | 38 | 62 | 112 |
Based on location of last detection of the 112 PIT-tagged sockeye salmon, 37 percent of the fish (41 fish) entered the Yakima River, 14 percent (16 fish) moved upstream in the Columbia River, 2 percent (2 fish) moved downstream from McNary Dam, and 46 percent (51 fish) were not detected (
Percentages of detected passive integrated transponder-tagged adult sockeye salmon at final locations by release month after release at the mouth of the Yakima River, Washington, 2020. %, percent.
Figure 9. Pie diagrams showing percentages of detected passive integrated transponder-tagged adult sockeye salmon at final locations by release month after release at the mouth of the Yakima River, Washington, 2020
During 2020, a total of 56 PIT-tagged sockeye salmon were detected in the Yakima River after tagging and release at Bonneville Dam (14 fish), the mouth of the Yakima River (41 fish), and Priest Rapids Dam (1 fish). Upstream movement by PIT-tagged fish in the Yakima River occurred primarily during early July and September (
Table 6. Number of passive integrated transponder-tagged sockeye salmon detected at Prosser and Roza Dams in the Yakima River, and the percentage of fish that successfully arrived at Roza Dam after passing Prosser Dam (percentage successful), by week of arrival at Prosser Dam, Washington, 2020
[Tagged fish were released at the Bonneville and Priest Rapids Dams, and at the mouth of the Yakima River. mm-dd-yy, month-day-year]
From |
To |
Detected at |
Detected at |
Percentage |
07-01-20 | 07-07-20 | 12 | 9 | 75 |
07-08-20 | 07-14-20 | 0 | 0 | 0 |
07-15-20 | 07-21-20 | 0 | 0 | 0 |
07-22-20 | 07-28-20 | 0 | 0 | 0 |
07-29-20 | 08-04-20 | 0 | 0 | 0 |
08-05-20 | 08-11-20 | 0 | 0 | 0 |
08-12-20 | 08-18-20 | 1 | 1 | 100 |
08-19-20 | 08-25-20 | 0 | 0 | 0 |
08-26-20 | 09-01-20 | 1 | 0 | 0 |
09-02-20 | 09-08-20 | 7 | 3 | 43 |
09-09-20 | 09-15-20 | 21 | 17 | 81 |
09-16-20 | 09-22-20 | 11 | 1 | 9 |
09-23-20 | 09-29-20 | 3 | 0 | 0 |
56 | 31 | 55 |
Number of passive integrated transponder-tagged sockeye salmon arriving at Prosser Dam by date in the Yakima River after tagging at Bonneville Dam (number of fish [
Figure 10. Graph showing number of passive integrated transponder-tagged sockeye salmon arriving at Prosser Dam by date in the Yakima River after tagging at Bonneville Dam, the mouth of the Yakima River, and Priest Rapids Dam, Washington, 2020
Hour of first arrival of passive integrated transponder-tagged sockeye salmon at Prosser Dam in the Yakima River, after tagging at Bonneville Dam (number of fish [
Figure 11. Graphs showing hour of first arrival of passive integrated transponder-tagged sockeye salmon at Prosser Dam in the Yakima River, after tagging at Bonneville Dam, the mouth of the Yakima River, and Priest Rapids Dam, Washington, 2020
Hour of passive integrated transponder-tagged sockeye salmon arrival at Prosser and Roza Dams in the Yakima River, Washington, 2020. The size of circles is proportional to the number of fish represented in each value. Fish were tagged at Bonneville Dam (number of fish [
Figure 12. Graph showing hour of passive integrated transponder-tagged sockeye salmon arrival at Prosser and Roza Dams in the Yakima River, Washington, 2020
Number of adult passive integrated transponder-tagged sockeye released in the Columbia River Basin that only were detected at Prosser Dam (open boxes) and both Prosser and Roza Dams (shaded boxes), Washington. Water temperature in the Yakima River is plotted on the right y-axis. Detected fish were released at Bonneville Adult Fish Facility (number of fish [
Figure 13. Graph showing number of adult passive integrated transponder-tagged sockeye released in the Columbia River Basin that only were detected at Prosser Dam and both Prosser and Roza Dams, Washington
Tagged sockeye salmon experienced a range of temperatures in the Yakima and Columbia Rivers. Fish released at Prosser Dam experienced water temperatures in the Yakima River ranging from 16 to 24 °C in June and 10–22 °C in July (
Results from this and other studies suggest that a substantial number of sockeye salmon destined for the Yakima River fail to reach Roza Dam where they are collected and transported upstream from Cle Elum Dam for spawning. We found that only 21 of the 144 (15 percent) sockeye salmon tagged and released during this study eventually moved upstream in the Yakima River and arrived at Roza Dam. During our 2019 study, a total of 60 sockeye salmon were tagged and released in the Yakima River and at the mouth of the Yakima River but only 1 tagged fish was collected at Roza Dam (
These findings support the hypothesis that elevated summer water temperatures create a thermal block that negatively affects the migration of Yakima River sockeye salmon. Existing data show that Yakima River sockeye salmon largely are absent from the lower Yakima River during summer when the water temperature exceeds 20 °C. However, during this time, many fish destined for the Yakima River are present in the Columbia River at the mouth of the Yakima River. After experiencing the thermal block of the Yakima River for an extended period, some of these fish eventually move to other Columbia River subbasins prior to the onset of spawning. The inhibited migration associated with higher water temperatures is consistent with movement barriers we observed between fixed tracking sites. Specifically, the probability of a fish reaching the adult trap at Roza Dam decreases when the passage date at Prosser Dam moves later into the summer, until September when water temperatures begin to drop. Passage counts for sockeye salmon adults at Prosser Dam are very low when water temperature is greater than 20 °C in the lower Yakima River. Additionally, telemetry results have shown that tagged fish moved downstream and out of the Yakima River during periods of increasing water temperature, and only reentered the river when it cooled to 20 °C or less (
Results from the study confirmed that piscivorous birds consume adult sockeye salmon during upstream migration in the Yakima and Columbia Rivers. We determined that at least 6 of the 13 radio-tagged sockeye salmon released in the Prosser Dam forebay were consumed by piscivorous birds. The transmitter from one of these fish was recovered in the tailrace of John Day Dam, which indicates that the fish was consumed in the Prosser Dam-to-Sunnyside Dam reach and transported to the Columbia River, and that the transmitter was deposited at the recovery location. Although we were able to confirm that piscivorous birds consumed radio-tagged fish upstream from Prosser Dam, we do not know if the fish were alive and healthy, sick, or dead at the time of consumption. Other data sources provide additional information about bird consumption as well. Several PIT tags from adult sockeye salmon tagged in 2020 at Bonneville and Priest Rapids Dams, and the mouth of the Yakima River were recovered on islands with bird colonies where fish predation has been documented (
Dorsal wound on an adult sockeye salmon trapped for radio-tagging at Prosser Dam, Washington, on June 26, 2019. Photograph by Tobias J. Kock, U.S. Geological Survey.
Figure 14. Photograph showing dorsal wound on an adult sockeye salmon trapped for radio-tagging at Prosser Dam, Washington, on June 26, 2019.
Growing evidence suggests that diversion dams alter migration behavior by adult sockeye salmon in the Yakima River. Residence times at most telemetry monitoring sites were low (less than 5 hours) during 2019 and 2020, but extended residence times (greater than 24 hours) were observed at Sunnyside, Prosser, and Wanawish Dams. Thus, migration behavior in the lower Yakima River seems to consist of rapid upstream movements that are delayed when fish encounter diversion dams. A study conducted on the upper Yakima River in 2018 (
Finally, data collected during 2019 and 2020 suggest that sockeye salmon primarily migrate past cool water sites in the lower Yakima River and spend little time holding at these locations. Although observations are limited to a low number of tagged fish, residence times at cool water sites have been consistently low during the 2 years of study. Future research using techniques such as snorkeling and underwater videography would be helpful. These approaches would allow researchers to identify and quantify fish species present at these sites during periods when summer water temperature exceeds 20 °C. This information would be useful for better understanding the relative importance of these sites during summer, and for potentially designing studies to collect additional information.
Water temperature use data (thick black line) collected by a radio transmitter inside an adult sockeye salmon (fork length 44 centimeters) tagged and released at Prosser Dam on June 20, 2020. Transmitter was recovered approximately 100 meters upstream in Sulphur Drain, which enters the Yakima River near Sunnyside, Washington, on July 8, 2020. Water temperature data from the Columbia River (blue line; streamgage PAQW, Pasco, Washington) and Yakima River (red line; Gage CFSW; Chandler Fish Screens) are included for reference.
Water temperature use data (thick black line) collected by a radio transmitter inside an adult sockeye salmon (fork length 49 centimeters) tagged and released at Prosser Dam on June 19, 2020. Transmitter was recovered near the Chandler Fish Handling Facility on July 8, 2020. Temperature peak during June 21–22, 2020 likely was owing to the tag being inside a piscivorous bird. Water temperature data from the Columbia River (blue line; streamgage PAQW, Pasco, Washington) and Yakima River (red line; streamgage CFSW; Chandler Fish Screens) are included for reference.
Water temperature use data (thick black line) collected by a radio transmitter inside an adult sockeye salmon (fork length 48 centimeters) tagged and released at Prosser Dam on June 22, 2020. Transmitter was recovered in the tailrace of John Day Dam on October 27, 2020. Temperature peak during June 24–26, 2020 likely was owing to the tag being inside a piscivorous bird. Water temperature data from the Columbia River (blue line; streamgage PAQW, Pasco, Washington) and Yakima River (red line; streamgage CFSW; Chandler Fish Screens) are included for reference.
Water temperature use data (thick black line) collected by a radio transmitter inside an adult sockeye salmon (fork length 48 centimeters) tagged and released at Prosser Dam on June 20, 2020. Transmitter was recovered 6 river kilometers downstream from Sunnyside Dam on July 22, 2020. Water temperature data from the Columbia River (blue line; streamgage PAQW, Pasco, Washington) and Yakima River (red line; streamgage CFSW; Chandler Fish Screens) are included for reference.
Water temperature use data (thick black line) collected by a radio transmitter inside an adult sockeye salmon (fork length 47 centimeters) tagged and released at Prosser Dam on June 20, 2020. Transmitter was recovered 16 river kilometers downstream from Sunnyside Dam near Buena, Washington, on July 22, 2020. Temperature peak during June 24–25, 2020 likely was owing to the tag being inside a piscivorous bird. Water temperature data from the Columbia River (blue line; streamgage PAQW, Pasco, Washington) and Yakima River (red line; streamgage CFSW; Chandler Fish Screens) are included for reference.
Water temperature use data (thick black line) collected by a radio transmitter inside an adult sockeye salmon (fork length 48 centimeters) tagged and released at Prosser Dam on June 20, 2020. Transmitter was recovered 16 river kilometers downstream from Sunnyside Dam near Buena, Washington, on July 22, 2020. Highly variable temperatures after June 26 likely occurred because the transmitter was not present in a live fish during this period. Water temperature data from the Columbia River (blue line; streamgage PAQW, Pasco, Washington) and Yakima River (red line; streamgage CFSW; Chandler Fish Screens) are included for reference.
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