Progress Report. Effects of Water Temperature Exposure on Spawning Success and Developing Gametes of. Migrating Anadromous Fish

Transcription

1 Progress Report Effects of Water Temperature Exposure on Spawning Success and Developing Gametes of Migrating Anadromous Fish Study Code: ADS by Ryan Mann and Chris Peery Fish Ecology Research Laboratory, ICFWRU University of Idaho Moscow, ID to Walla Walla District U.S. Army Corps of Engineers Walla Walla, WA August 2005

2 Abstract Examinations into the effects of high sub-lethal water temperature exposures on the reproductive success of migrating anadromous fish were preformed. Investigations included analysis of migration success and the subsequent embryo viability of steelhead and fall Chinook salmon. Radio telemetry methods were used to study migration patterns related to temperature, while viability tests were completed at Lyons Ferry, Nez Perce, and Dworshak Hatcheries. One hundred steelhead and one hundred Chinook salmon were tagged at Ice Harbor Dam from July 2 to September 30, We recovered 88 of 200 external and 45 of 108 internal temperature tags released. Included in these, we recovered both the external and internal temperature tags from 15 steelhead and 15 Chinook salmon. Comparisons between these showed that internal body temperature tracked external water temperature closely. Chinook salmon were exposed to temperatures as high as 23.6 C, and had total migration temperature exposures as high as 19.2 degree days above 20 C and 60.0 degree days above 18 C. Steelhead experienced temperatures maximum temperatures of 24 C and had total migration temperature exposures as high as 15.7 degree days above 20 C and 48.8 degree days above 18 C. Migration temperature exposures were highly correlated with release date and the temperature at Ice Harbor Dam at the time of passage. Embryo mortality was tracked for thirty Fall Chinook, and ranged from 1.11% to 19.84%, though one brood exhibited losses over 99% due to soft shell disease. Total embryo mortality was tracked for six steelhead, and ranged from 5.67% to 81.21% with steelhead generally having higher losses than fall Chinook. Embryo mortality data in relation to temperature exposures were analyzed for 13 Chinook salmon. The five fish with the highest temperature exposures above 20 C exhibited five of the six highest embryo mortalities at the eye up stage and the button up stage. A similar, but weaker, relationship was observed when temperature exposures were calculated using an 18 C threshold. i

3 Introduction The demand for irrigation water, commercial navigation, and electricity has resulted in the construction of multiple dams on northwest American rivers in the last century. In the Columbia River watershed, of the Pacific Northwest, USA, salmon (Oncorhynchus spp.) must pass up to nine major dams to reach natal spawning areas of Washington or Idaho. Although number of returning numbers have increased from historic lows during the early 1990 s, populations have trended downward over the last 150 years, resulting in the listing of many Columbia River salmon and steelhead stocks under the Endangered Species Act (NRC 1996, McClure et al. 2003). One concern is how modified flows and temperature conditions within the system may impact salmon migrants. During this study, we have been documenting temperature exposures and investigating the effects of variable water temperatures on the reproductive success of migrating adult Chinook salmon (O. tshawytscha) and steelhead (O. mykiss). Temperature exposure can be defined as the thermal regime that individual adults and their gametes experience during upstream migration. An understanding of temperature exposure for during fish migration can be achieved by evaluating at least two components: the average temperature experienced and estimates of thermal units experienced above a physiologically important threshold (e.g. degree-days above 18 C). This report focuses on these two estimates of temperature exposure and future analyses will also examine other measures of exposure, such as the maximum temperature and variability in temperatures experienced. Background Impoundments decrease flow velocities and increase water residence times in dammed river systems. Longer residence times and the larger surface area within reservoirs result in earlier warming in the spring, increased temperatures during summer months, and later cooling 1

4 in the fall. As a result, the average summer temperatures of the Columbia and Snake rivers warm sooner, reach higher maximum and remain warm later into the fall compared to pre-dam periods (Quinn and Adams 1996; Quinn et al. 1997). During the summer and early fall it is not uncommon for the temperature to rise above levels thought to be physiologically stressful for migrating adult salmonids (~18-20 C; Peery et al. 2003, Richter and Kolmes 2005). Little is known about how the altered thermal regime affects migrating adult anadromous fish or their developing gametes. Previous studies on factors influencing egg quality of fish have focused primarily on conditions experienced by eggs following spawning. Few studies have been conducted to document the effects of warm water exposure to adult fish have on gamete development and little is known of these effects on salmonids. During summer and early autumn, temperature is arguably the most significant environment factor involved with anadromous fishes migration due to its impact on normal physiological, metabolic, and behavioral processes. The goal of this project is to study the effects of warm water temperatures on movement and overall spawning success of adult salmon and steelhead returning to the Snake River. We used radio telemetry to collect data for analyses of movement behavior for adult salmon and steelhead migrating through the lower Snake River and to spawning areas. Two hundred fish were outfitted with radio transmitters and temperature recorders in 2004 to document their movement behavior and temperature exposures. Additionally, we have made an examination of the quality of salmon and steelhead eggs and fry of tagged fish that return to hatcheries on the Snake and Clearwater rivers to determine if the viability of developing gametes is related to temperatures adults were exposed to during migration. Other potential factors that will be explored using the 2004 dataset include differences in migration and spawning success 2

5 for natural and hatchery (fin-clipped) fish. Finally, I have made temperature profiles for the migrating fish from recaptured temperature recorders that represent the full thermal regime experienced. We are currently determining if it will be possible to use PIT-tag and water quality monitoring data at dams to accurately infer temperature exposure without the use of temperature loggers on fish. Study Objectives: 1) Assess relationship between sub-lethal high temperatures and movement behavior and time of passage for adult Chinook salmon and steelhead migrants. 2) Assess relationship between sub-lethal temperature exposures for adult Chinook salmon and steelhead during upriver migration and the quality of their gametes, embryos and fry. 3) Assess the relationship between temperature and migration success (escapement) for natural or hatchery Chinook salmon and steelhead. Methods Fish Collection For this study, adult Chinook salmon and steelhead were tagged throughout summer 2004 using a trap in the south-shore fish ladder of Ice Harbor Dam, river kilometer (rkm) 16. This is the first dam that migrating adult fish encounter on the Snake River. Picket screens near the top of the ladder guided fish through the main trap channel opening, which was approximately one meter by 1.5 meters. Once a desired fish entered the main channel, the front and back gates were closed using pneumatic rams, which were controlled by a trap operator within a waterproof floating booth. The booth has viewing windows that provided a visual of the fish in the main channel and fish in the side transition area (See Figure 1). Trapped fish were diverted using a series of doors to a separate holding cage. Fish were held in the holding cage door to await transport. When the desired number of fish had been collected, a crane was used to lift the 3

6 holding pen out of fishway and over a fish tank trailer. The holding pen contains a solid bottom that retains water. This kept collected fish submerged at all times during the transfer. The fish were released into the aerated transport tank on a trailer using a canvas sleeve in the bottom of the holding pen (tied closed prior to fish trapping). The fish were then moved to the tagging site located at the juvenile fish facility in the transport tank. Tagging At the tagging site, fish were moved using rubber nets to an anesthetic tank (20 ppm clove oil). Once sedated, fish were moved to a smaller tagging tank. The fork length of the fish was taken and all fish were inspected for clips, marks, injuries and the overall condition of the fish was recorded. Fish were scanned for Passive Integrated Transponder (PIT) tags and one was administered by injection into the ceolom of the fish if none were present. Depending on the size of the fish, a data storage tag (DST) (90mm by 20mm, 34g in air), 7-volt (80mm by 16mm diameter, 29g in air), or 3-volt (43mm by 14mm diameter, 11g in air) transmitter tag was inserted intra-gastrically. An external temperature recorder was also sutured at the base of the dorsal fin to record external water temperature. If the fish was determined to be of hatchery origin, based on clips and/or the presence of coded wire tags (CWT), the fish received a unique operculum punch to assist with identification at the hatchery, and to aid in other studies concerned with coded-wire tagged fish. After tagging, each fish was moved to a recovery tank. Once the fish was determined to be fully recovered from anesthesia, the fish was diverted into the juvenile bypass flume which transported it to the tailrace of Ice Harbor Dam. 4

7 Telemetry Monitoring Dams on the lower Snake River have been outfitted with radio receivers that record when fish with transmitters move through the tailraces and in and near collection channels and fish ladders. Receivers with aerial antennas were also located at locations in reservoirs and at mouths of major tributaries in the Snake River. Data was downloaded from these receivers to portable computers and transferred to the main database housed in Seattle, Washington. Information on fish movements was also collected by tracking areas between and upstream from fixed receiver sites using a truck-mounted receiver and aerial antenna. Information obtained from those tracking and additional boat tracking will help to determine the behavior of the fish in the vicinity of Ice Harbor Dam and in the upstream reservoirs and to determine which fish successfully reached spawning areas. Mobile tracking information will also allow an evaluation of the effectiveness of this new release method. Evaluation of Gamete Quality Effects of temperature exposure was related to gamete quality by tracking egg batches from fish that were spawned at regional hatcheries in the Snake and Clearwater rivers. Weights and lengths of each adult that returned to the hatchery were used to estimate age class. Indexes of gamete quality were fecundity and fertilization success. Embryo quality was determined from percent survival at the eye-up, hatching, and button-up stages, and the number of abnormal embryos per female. We chose to use randomly selected males in one-to-one spawning because several studies have found greater maternal than paternal influence on egg and embryo quality (e.g. Nagler et al. 2000, Saillant et al 2001). Water temperature exposures were estimated by calculating the number of degree days a fish was exposed to a threshold temperature. We chose 5

8 the threshold of 20 C because this is the upper incipient lethal temperature (UILT) for salmon. The UILT is the water temperature at which theoretically half of the population would survive with permanent exposure (Houston 1982). The UILT is also the upper limit of tolerance and the lower limit of the zone of resistance for a fish (Jobling 1981) and appears to be a cutoff for preferred temperature of migrating adult Chinook salmon and steelhead (Coutant 1977; Cherry et al. 1977). In these preliminary analyses, temperature exposures were calculated from the external temperature recorders by averaging all the temperature records for a single day. If the daily averages were greater than 20 C, 20 was subtracted from them and the total represented the temperature exposure measured in degree days above 20 C. These estimates probably systematically underestimate the true degree day exposures because exposures above 20 C occurring on days with mean temperatures below the 20 C threshold were not included. Because other authors suggest significant physiological effects at lower temperatures (e.g., Richter and Kolmes 2005), we also performed analyses assuming an 18 C temperature threshold. Two methods were used by participating hatcheries to determine fecundity for a given female. At Lyons Ferry Hatchery, fecundity was determined by massing out 100 live eggs and extrapolating this mass to the weight of the entire egg batch. All of the dead and/or abnormal eggs were counted and removed before massing all live eggs. This number was then added back in to determine total fecundity. An equation was used to remove the water weight in the calculation. At Nez Perce Tribal Hatchery and Dworshak Hatchery the eggs were processed through a Van Galen Fish Egg Sorter, which automatically removes the dead eggs and individually counts the number of embryos. At eye-up stage, the embryos could be clearly seen through the vitelline envelope of the egg, and the shell was hard enough to safely handle the eggs at this stage. Eying success was 6

9 determined by shocking the eggs after attaining 580 temperature units, which corresponded to approximately 27 days for Chinook salmon and 15 days for steelhead. Eggs that turned white following shocking were counted as mortalities and removed from incubation trays. This number was subtracted from the fecundity, or total number of eggs, and then divided by the fecundity to determine eying success (ES) as; % ES = (F-E d )/F where F represents the fecundity, and E d represents dead eggs. Abnormal formations of embryos were identified and removed throughout the life stages of the embryos. Abnormal eggs were collected from the egg batches at the eye-up stage. Abnormalities during the eyed stage included unusually high numbers of unfertilized eggs, live embryos that were haploid, and embryos with eye numbers other than two. Most abnormalities presented themselves at the button-up stage and included twisted fry, Siamese twins, and fry with malformed tails or mouths. Finally, hatching success, the percentage of eggs that reach the fry stage, was determined by examining egg trays just prior to the alevins being removed to the rearing ponds. According to Dworshak practices with steelhead, embryos are normally transferred from trays to upwelling incubators before hatching. For this project, however, all the embryos were raised in the incubation trays until button-up. General observations of the timing of life stages including eyeing, hatching, and swim-up were also recorded for each batch of embryos. Migration Success Migration histories of individual tagged fish are currently being determined from records at fixed receivers in tributaries, tracking of fish in tributaries, and recaptures at hatcheries and 7

10 carcasses located during spawning ground surveys. These histories will be used to determine escapement to tributaries and hatcheries. Migration success will be related to tag data, migration progression, and temperature exposures as determined from internal and external temperature recorders. Temperature Profiles Previously, studies to assess temperature exposures of migrating fish have relied on temperature recorded along specific intervals of the rivers (e.g. Torgersen et al. 1999). These measures may not reflect actual temperatures to which fish are exposed, as in the case of the dam scroll case measurements (McCullough 1999). By using temperature recorders mounted on and in fish, we have been able to determine real temperatures that fish were exposed to while migrating and their concurrent body temperatures. External temperature recorders recorded at intervals of 60 minutes for Chinook salmon, and 80 minutes for steelhead. By increasing the interval time for steelhead we were able to achieve a longer sample period to correspond with the longer migration interval for steelhead. The DST tag, placed gastrically, recorded the internal temperatures of individual fish at 30 second intervals. Figures 2 and 3 are example temperature profiles from individual fish. Comparisons between the data received from the external temperature recorder and the internal DST tags revealed that body temperature closely tracks external temperature (e.g. Figure 4). 8

11 Preliminary Results Summary of Tagging We tagged 100 adult Chinook salmon and 100 steelhead from 2 July to 30 September 2004 (Figure 5). Every fish received an external temperature recorder and a gastric radio transmitter tag. Of the two hundred fish tagged, 108 fish (70 Chinook and 38 steelhead) received dual radio transmitter and internal data storage tags (DST) that recorded internal temperature, 89 (29 Chinook and 60 steelhead) received either a 3- or 7-volt radio transmitter, and 3 (1 Chinook and 2 steelhead) received dual radio transmitter and acoustic map tags. All fish recovered fully from the tagging process and appeared in good health when released to the tailrace of Ice Harbor Dam. As of 15 July 2005, we have recovered either internal or external temperature tags from 103 of the 200 fish tagged. The recovery of the external tags during the peak of the summer was limited because the Lower Granite Dam adult fish trap was not operated at water temperatures above 72 F. A total of 88 external temperature tags were recovered and successfully downloaded, 35 from Chinook salmon, and 53 from steelhead. Forty five internal DSTs were recovered (24 Chinook salmon and 21 steelhead). We have both the internal and external temperature data for 15 Chinook and 15 steelhead. Comparisons between these are important for determining the lag time between ambient temperature and internal body temperature and the accuracy of the readings. Temperature Data External temperature tags were recovered primarily at the adult fish trap at Lower Granite Dam. In addition, tags were turned in by fishermen, and from hatcheries and diversion weirs. 9

12 Although 88 recorders were successfully downloaded, our overall recovery rate was 95 of 200 (47.5%) temperature tags released; useful data from seven tags could not be retrieved. Two tags appeared to be turned on correctly, yet they shut off after only recording one data point and five tags reported errors and could not be successfully downloaded. The manufacturer attributed this malfunction to incorrect connection inside the logger. The manufacturer estimates a failure rate of about three percent in the temperature recorders, but we our failure rate was approximately twice that. A wide range of temperature exposures were observed for both species, from 0 to 19.1 degree days above 20 C and from 0 to 63.0 degree days above 18 C (Table 1 and 2). These temperature exposures were highly dependent on the run timing (Figure 6 and 7). No fish released after 9 September was exposed to daily average temperatures of 20 C or higher. Degree-day calculations were repeated for Chinook salmon using 18 C as a baseline temperature indicating the onset of physiological stress (e.g. Richter and Kolmes 2005). These results are also summarized in Table 1. Of the 88 external temperature tags successfully downloaded, it was determined that 81 of these fish continued migrating up the Snake River after their release at Ice Harbor Dam. The other seven were either detected in the Columbia River using telemetry records or PIT detections, or were recovered dead. Temperature exposures for the 81 successfully downloaded Snake River run fish were graphed compared to the release date of these fish (Figure 6). Water temperatures of the Ice Harbor tailrace and forebay peaked in early August, 2004 and peak temperatures coincided with peak degree-day exposures. Unfortunately, the fewest data points were collected during the warmest temperatures because the Lower Granite Dam adult fish trap was shut down at high temperatures. Temperature exposures were also compared to the first PIT 10

13 tag detection at Ice Harbor Dam rather than release date (Figure 7). This represents the reascension of Ice Harbor Dam after being tagged, and reveals a similar pattern to that obtained when using release date. The re-ascension method may more accurately represent a radio-tagged fishes temperature exposure because it takes into account time spent below Ice Harbor Dam. By matching a regression curve to these data sets, temperature exposures can be approximated for the other fish that were released at Ice Harbor without recovery of the temperature tag using either release dates or PIT records (compare Figures 6 and 7). Because temperature exposures in degree days matched water temperatures at Ice Harbor we examined the relationship between degree-day exposures and water temperature at Ice Harbor Dam on the day of passage after tagging (Figure 8). As suggested, temperature exposures appear to be related to the temperature at Ice Harbor Dam. The only fish that do not fit this trend are Chinook salmon that spent more than two weeks and the steelhead that spent more than three weeks in the system below Ice Harbor Dam before re-ascending after tagging (Figure 8). We are currently working on a system for analyzing the data received from DST tags to more accurately calculate degree-days over shorter time intervals. Results from preliminary analysis suggest that the internal DST records follow those of the external temperature tags within the hour (Figure 4), suggesting that the external temperature recorders can be used as a measure of internal temperature exposure. The temperature data from the DST tags will be incorporated into future analyses of run timing, escapement, and embryo viability. Hatchery Work May 31, 2005 concluded the first field season for this project. Embryo viability data were collected from Lyons Ferry Fish Hatchery, Nez Perce Tribal Hatchery, and Dworshak 11

14 National Fish Hatchery. Sampling on Snake River fall Chinook salmon occurred from 20 October 2004, the first day of spawning, to 8 February 2005, the day at which all the fry had absorbed their yolk sacs. During this time, the embryos of 30 female adult Chinook salmon were tracked. Fifteen of these fish were tagged at Ice Harbor Dam, nine were tagged at Bonneville Dam, and six were PIT-tagged fish that are being used as a supplement to this study. Twenty six fish were spawned at Lyons Ferry Hatchery, and four were spawned at Nez Perce Hatchery. There was a large variation in the mortality among egg batches of individual Chinook salmon with one egg batch exhibited over 99 percent mortality. This egg batch had a condition known as soft shell disease. The vitelline envelopes of embryos with soft shell disease are extremely soft and brittle even at the eye-up stage when embryos are normally safe to handle. This makes the embryos susceptible to breaking or death from physical disruption, and potentially more susceptible to premature hatching (Barnes et al. 2003). The cause of this disease is as of yet not understood. Disregarding this batch, there was still high variation in mortalities, ranging between about 1 to 20 % (Table 3). Only six of the thirty batches monitored had greater losses after eye-up stage than before. Spawning for steelhead began on 8 February 2005 at Dworshak National Fish Hatchery. Only six adult female steelhead were spawned during the spawning season for this project. Because Dworshak receives a large number of steelhead and the ladder at the hatchery was only open for short periods, many radio-tagged steelhead may not have been sampled. Finally, we did not have the advantage of transporting fish from Lower Granite Dam as we did with the fall Chinook salmon. Five of the six steelhead spawned were tagged at Ice Harbor Dam. One fish was tagged at Lower Granite as part of another study. This fish was trapped at the weir in Kooskia, ID, and 12

15 transported to the hatchery for spawning. In general, mortality was greater in steelhead than Chinook salmon in both stages of development analyzed. Mortality results are summarized in Table 4. Embryo mortality was compared to the temperature exposure of the adult Chinook in the Snake River (Figure 9 and 10). Five fish with the highest temperature exposures, calculated as degree days above 20 C, had five of the six highest mortalities for both stages of embryo development. The relationship was not as defined when looking at degree days over 18 C. This suggests that temperatures above 20 C may have more effect on developing gametes during migration. The fish with the highest embryo mortalities (19.84%) had only minor exposer to daily temperatures averaging over 18 C. Temperature exposures received from DST tags and approximated from PIT tag detections will be used to add to the analysis of embryo viability as a dependent variable of temperature exposure. Once all of the available temperature exposures are calculated, ANCOVA models will be used to explore other cofactors affecting embryo viability such as female size. We are currently coding and analyzing the radio telemetry records from last summer and fall. Once this is done, the telemetry data will be integrated with the temperature data to assess whether temperature exposure had an effect on final migration position and overall escapement success (Objectives 1 and 3). 13

16 Figure 1: Sketch showing top view of the fish trap located at the top of the Ice Harbor Dam south-shore fishway. A is the collection area for fish waiting to enter the trap. B is the main channel area. Desired fish are trapped in this area by closing the gate upstream and downstream of the fish using switches in the operating booth. The fish can then be either released to the exit area E to continue migrating upstream or diverted to the transition area C if the fish is going to be tagged. Desired fish are held within the cage area D to await transportation to the tagging area. 14

17 Temperature Profile Temperature ( C) /28/ /29/ /30/ /01/ /02/ /03/ /04/ /05/ /06/ /07/ /08/ /09/ /10/ /11/ /12/ /13/ /14/2004 Date Figure 2: Temperature profile downloaded from external recorder on an adult steelhead released relatively late in the year and recaptured at Lower Granite Dam. Each hash mark along the x- axis represents one day at approximately noon. Temperatures start on the release date and the recapture point is the right extreme on the graph. Because this fish migrated later in the season, it was not exposed to temperatures above 20 degrees in the Snake River. Daily fluctuations in temperature can be seen in the graph, especially immediately following release at Ice Harbor Dam. 15

18 Temperature Profile Temperature ( C) /18/ /19/ /20/ /21/ /22/ /24/ /25/ /26/ /27/ /28/ /29/ /30/ /31/ /01/ /02/ /03/2004 Date Figure 3: Temperature profile downloaded from an external recorder on a Chinook salmon released just after peak water temperature and recaptured at Lower Granite Dam. Each hash mark along the x-axis represents one day at approximately noon. Temperatures start on the release date and the recapture point is the right extreme on the graph. 16

19 External and Internal Temperature Comparison /2/2004 9/3/2004 9/3/2004 9/4/2004 9/4/2004 9/5/2004 9/5/2004 9/6/2004 9/6/2004 9/7/2004 9/7/2004 9/7/2004 9/8/2004 9/8/2004 9/9/2004 9/9/2004 9/10/2004 Temperature ( C) ETEMP AVITEMP MINTEMP MAXTEMP Date Figure 4: Comparisons between temperatures measured on external (ETEMP) and internal recorders. The light blue line (MAXTEMP) is the maximum internal temperature recorded by the DST tag for an hour. The yellow line (MINTEMP) is the minimum internal temperature recorded for an hour. Pink line is the average of the temperature recordings (AVTEMP) for a given hour. 17

20 Tagging Effort Fish Number Water Temperature Tagged Fish IH Temp /1/2004 7/8/2004 7/15/2004 7/22/2004 7/29/2004 8/5/2004 8/12/2004 8/19/2004 8/26/2004 9/2/2004 9/9/2004 9/16/2004 9/23/2004 9/30/2004 Date Figure 5: Timing of tagging effort and water temperatures at Ice Harbor Dam, Each cross represents one fish tagged on the date indicated. Tagging operations at Ice Harbor Dam were stopped on occasions due to high water temperatures, visible as gaps during the middle of the tagging season. 18

21 Table 1: Tagged Snake River Chinook salmon with recovered temperature data. Listed are the channel and code of the radio tag administered, the date of release, and the temperature exposure measured in degree days above 20 C and 18 C, and median and maximum temperature for their migration. Fish with comparatively low median temperatures (ex , ) spent more than half their migration in the cold water outflow from Lyons Ferry Hatchery (~11 C). Channel 25 Code 123 excludes a median and maximum temperature because this fish was found on a spawning carcass survey, and the time of death could not be determined. Chan Code Release Date Degree Days Above 20 C Degree Days Above 18 C Median Temps Max Temp /2/ /6/ /7/ /8/ /12/ /15/ /19/ /5/ /18/ /25/ /25/ /26/ /26/ /26/ /26/ /30/ /30/ /30/ /30/ /31/ /31/ /1/ /1/ /1/ /1/ /2/ /7/ /9/ /16/ /21/ /21/ /28/

22 Table 2: Tagged Snake River steelhead with recovered temperature data. Listed are the channel and code of the radio tag administered, the date of release, and the temperature exposure measured in degree days above 20 C and 18 C, and median and maximum temperature for their migration. Fish with comparatively low median temperatures (ex , , ) spent more than half their migration in the cold water outflow from Lyons Ferry Hatchery (~11 C) or were recaptured in the winter. Chan Code Release Date Degree Days Above 20 C Degree Days Above 18 C Median Temps Max Temp /2/ /8/ /14/ /15/ /20/ /3/ /18/ /26/ /30/ /31/ /31/ /31/ /1/ /1/ /2/ /2/ /2/ /2/ /7/ /8/ /8/ /8/ /8/ /9/ /9/ /9/ /9/ /13/ /13/ /14/ /14/ /15/ /15/ /16/ /16/ /17/ /17/ /21/ /21/

23 /22/ /22/ /23/ /23/ /23/ /28/ /28/ /29/ /30/ /30/

24 Release Dates Exposure Calibration Curve Steelhead 22.5 Chinook Degree Days Above 20 C IH Tailrace Temp IH Forebay Temp Water Temperature ( C) /22/2004 7/12/2004 8/1/2004 8/21/2004 9/10/2004 9/30/ /20/2004 Release Date Figure 6: Relationship between release date and temperature exposures for all recaptured fish. Ice Harbor Dam tailrace and forebay water temperatures are graphed for reference. 22

25 IH PIT Tag Detections Temperature Exposure Curve Chinook Steelhead Degree Days Above 20 C IH Tailrace Temps IH Forebay Temps IH Water Temperature ( C) /22/2004 7/12/2004 8/1/2004 8/21/2004 9/10/2004 9/30/ /20/2004 Ice Harbor Detection Dates Figure 7: Relationship between Ice Harbor PIT-detection date and temperature exposures determined from external temperature recorders. PIT records are the first detection after returning to Ice Harbor Dam following tagging and release to the tailrace. Tagging began on July 2,

26 IH Tailrace Temp At Time of Re-ascension Water Temperature ( C) Chinook Steelhead Degree Days Above 18 C Figure 8: Relationship between temperature exposure and the tailrace water temperature at Ice Harbor at the time of first PIT tag detection. The three Chinook salmon indicated by the circle are those fish that spent more than two weeks below Ice Harbor Dam before re-ascending it posttagging. The three steelhead within the circle spent three weeks or more before re-ascending Ice Harbor Dam. 24

27 Table 3: Fall Chinook salmon embryo mortality. The six fish without channel and codes were the supplemental PIT tagged fish. Hatchery Chan Code Egg Batch ID Fecundity % Mortality To Eye Up % Mortality To Button Up Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Lyons Ferry Nez Perce Nez Perce Nez Perce Nez Perce

28 Table 4: Steelhead embryo mortality. Hatchery Chan Code Egg Batch ID Fecundity % Mortality To Eye Up % Mortality To Button Up Dworshak Dworshak Dworshak Dworshak Dworshak Dworshak Temperature Exposure vs. Viability Percent Mortality Mortality to Eye Up Mortality to Button Up Degree Days Above 20 C Figure 9: Percent mortality at the eye-up and button-up stages for fall Chinook salmon related to temperature exposure in degree days above 20 C. This graph only includes those fish that were spawned and we recovered external temperature recorders from (13 total). One egg batch with 99% mortality was excluded because the adult was tagged at the Bonneville Dam and had no external temperature recorder. 26

29 18 C+ Temperature Exposure vs. Viability Percent Mortality Mortality to Eye Up Mortality to Button Up Degree Days Above 18 C Figure 10: Relationship between percent mortality at the eye-up and button-up stages and temperature exposure in degree days above 18 C for fall Chinook salmon. This graph only includes those fish that were spawned and from which we recovered external temperature recorders (13 total). This data set excludes the brood with 99% mortality because the adult was tagged at the Bonneville Dam and had no external temperature recorder. 27

30 Literature Cited Barnes, M.E., R.J. Cordes, and W.A. Sayler Soft-egg disease in landlocked fall Chinook salmon eggs: possible causes and therapeutic treatments. North American Journal of Aquaculture 65: Cherry, D.S., K.L. Dickson, J. Cairns, Jr. and J.R. Stauffer Preferred, avoided, and lethal temperatures of fish during rising temperature conditions. Journal of Fisheries Research Board of Canada 34: Coutant, C.C Compilation of temperature preference data. Journal of Fisheries Research Board of Canada 34: Houston, A.H Thermal Effects upon Fishes. National Research Council of Canada. Associates Committee on Scientific Criteria for Environmental Quality. Ottawa, Canada. Jobling, M Temperature tolerance and the final preferendum rapid methods for the assessment of optimum growth temperatures. Journal of Fish Biology 19 (4): McClure, M. M., E.E. Holmes, B.L. Sanderson and C.E. Jordan (2003). A large-scale, multispecies status, assessment: Anadromous salmonids in the Columbia River Basin. Ecological Applications 13(4): McCullough, D.A A review and synthesis of effects of alterations to the water temperature regime on freshwater life stages of salmonids, with special reference to Chinook salmon. Prepared for the U.S. Environmental Protection Agency, Region 10, Seattle, Washington. Published as EPA 910-R , July Nagler, J.J., J.E. Parsons, and J.G. Cloud Single pair mating indicates maternal effects on embryo survival in rainbow trout, Oncorhynchus mykiss. Aquaculture 184: NRC (National Research Council) (1996). Upstream: Salmon and Society in the Pacific Northwest. Washington, D.C., National Academy Press. Quinn, T.P., and D.J. Adams Environmental changes affecting the migratory timing of American shad and sockeye salmon. Ecology 77: Quinn, T.P., S. Hodgson, and C. Peven Temperature, flow, and the migration of adult sockeye salmon (Oncorhynchus nerka) in the Columbia River. Canadian Journal of Fisheries and Aquatic Sciences 54: Peery, C.A., T.C. Bjornn, and L.C. Stuehrenberg Water temperatures and passage of adult salmon and steelhead in the lower Snake River. For U.S. Army Corps of Engineers, Walla Walla, Washington. 28

31 Richter, A. and S.A. Kolmes (2005). Maximum temperature limits for Chinook, Coho, and chum salmon, and steelhead trout in the Pacific Northwest. Reviews in Fisheries Science 13(1): Saillant, E., B. Chatain, A. Fostier, C. Przybyla, and C. Fauvel Parental influence on early development in the European sea bass. Journal of Fish Biology 58: Torgersen, C.E., D.M. Price, H.W. Li, B.A. McIntosh Multiscale thermal refugia and stream habitat associations of Chinook salmon in Northeastern Oregon. Ecological Applications 9: