Juvenile Progress Report ROGUE BASIN EVALUATION PROGRAM. r 1. Serdernber I'178. U.S. Army Corps of Engineers i ---, Ir III,, Rnsearch Oregon

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1 Juvenile Progress Report FISH & WILDLIFE REFERENCELIBRARY ROGUE BASIN EVALUATION PROGRAM U.S. Army Corps of Engineers i ---, Ir III,,."'I, I, fi 11 12( 144 Portland District ORF GO N r 1 Rnsearch Oregon Section Depa rtm ent of Fish a nd W icid I bse Serdernber I'178

2 PROGRESS REPORT ROGUE EVALUATION STUDY JUVENILE SALMONID STUDIES submitted to U. S. Army Corps of Engineers DACW C-O109 by the Research Section of the OREGON DEPARTMENT OF FISH AND WILDLIFE Prepared by Steven P. Cramer and James T. Martin Period Covered: January 1, 1977 to December 31, 1977 Date Submitted: August 1978 Contributing Authors: Steven L. Johnson, George H. Westfall, James T. Martin, Richard D. Ewing, and Raymond R. Boyce.

3 fi * e s # s P.. e o j a s s * * * C e e e o 2 * a TABLE OF CONTENTS Page INTRODUCTION..... METHODS... RESULTS Chinook... - Emergence Growth... Chanes in length time Growth _ rates determined from _. scal e analv! sis Bodycni tion Distribution and abundance ig a... I Migration t iming Migration rates Parr-smolt transformation studies. 58 Steelhead * t me genc Growth Changes in length through time Growth rates determined from scal e Bana lyws i S. g 76 Body condition... Distribution and abundance Migration Coho

4 Page Growth Migration Distribution and abundance Cutthroat Growth Abundance Migration LITERATURE CITED APPENDICES ii

5 Number FIGURES Page 1 Locations of permanent sampling stations for juvenile salmonids in the Rogue Basin Weekly mean length of juvenile chinook salmon at Sand Hole and High Banks in 1975, 1976 and Weekly mean length of juvenile chinook salmon at Table Rock and Savage Rapids in 1976 and Weekly mean length of juvenile chinook salmon at Matson and Almeda in 1975, 1976 and Weekly mean length of juvenile chinook salmon at Whiskey Bar and Winkle Bar in 1975, 1976 and Weekly mean length of juvenile chinook salmon at Agness and Hideaway in 1976 and Weekly mean length of juvenile chinook salmon at Canfield from 1974 to Weekly mean length of juvenile chinook salmon at Mail Boat Point and Coast Guard in 1976 and Weekly mean length of juvenile chinook salmon at Lobster Creek trap in 1976 and Weekly mean width of bands of five consecutive intracircular spacings on scales from juvenile chinook salmon at Table Rock in 1975 and Weekly mean length of juvenile chinook salmon in Big Butte Creek and the Illinois River in 1976 and Weekly mean length of juvenile chinook salmon at Murphy and Copelands in the Applegate River in 1976 and The mean length of juvenile chinook salmon in the Rogue River by river kilometer for three time periods in Weekly mean length of juvenile chinook salmon reared in the Corvallis laboratory at six different feeding levels in A regression showing the relationship between the mean width of the second band of scale circuli and mean growth rate of chinook salmon reared at the Corvallis laboratory in

6 Number FIGURES (continued) Page 16 The regression of mean scale circuli spacing on average growth rate of juvenile chinook salmon reared at the Corvallis laboratory in Means and 95% confidence intervals for band widths of juvenile chinook salmon scales collected at Table Rock, Gold Hill and Canfield in 1974 to Weekly mean width of the first band of five intracircular spaces on scales from juvenile chinook salmon at Canfield in 1974 to The relationship between slope from the regression of log weight on log length of juvenile chinook salmon and river kilometer, 1975 to The relationship between weight of a hypothetical 8.0 cm juvenile chinook salmon (calculated from regressions in Table 8) and river kilometer in 1975 to Weekly catch/unit effort of juvenile chinook salmon at Sand Hole, Table Rock and High Banks in Weekly catch/trap hour of juvenile chinook salmon at Savage Rapids in 1976 and Weekly catch/seine haul of juvenile chinook salmon at Matson and Almeda in Weekly catch/seine haul of juvenile chinook salmon at Whiskey Bar, Long Gulch and Illahe in Weekly catch/seine haul of juvenile chinook salmon at Agness, Hideaway and Canfield in Weekly catch/seine haul of juvenile chinook salmon at Mail Boat Point and Coast Guard in Weekly catch/seine haul of juvenile chinook salmon at Murphy and Copelands on the Applegate River and Big Butte Creek in Weekly catch/seine haul of juvenile chinook salmon in the Illinois River in Weekly catch/trap hour of juvenile chinook salmon in Lobster Creek in iv

7 Number FIGURES (continued) Page 30 Comparison of relative frequency histograms of migration rates of juvenile chinook salmon recaptured at Savage Rapids trap and by seine above km 122 in The influence of flow and turbidity on migration rate of fast migrant juvenile chinook recaptured at Savage Rapids trap in The influence of Julian day, length and flow on migration rate of slow migrant juvenile chinook recaptured at Savage Rapids trap in Relative frequency histogram of migration rates of juvenile chinook salmon branded at Table Rock and Savage Rapids and recaptured below km 45 in The influence of flow, turbidity, and Julian day on the migration rate of fast migrant juvenile chinook recaptured below km 50 in The influence of flow, turbidity and Julian day on migration rate of slow migrant juvenile chinook recaptured below km 50 in Monthly mean gill (Na+K)-ATPase specific activity of juvenile chinook salmon reared at different growth rates in the Corvallis laboratory in The relationship between size class and gill (Na+K)-ATPase specific activity of juvenile chinook salmon during different months of the year Monthly mean gill (Na+K)-ATPase specific activity in juvenile chinook salmon at several hypothetical growth rates The catch/trap hour and gill (Na+K)-ATPase specific activity of juvenile chinook salmon at Savage Rapids trap in Monthly mean condition factor of juvenile spring chinook salmon reared at Cole Rivers Hatchery in Changes in specific activity of gut (Na+K)-ATPase in juvenile chinook salmon during Changes in buoyancy of juvenile chinook salmon during The relationship between rate of change in length (cm/day) and river kilometer for age O+ steelhead in 1976 and v

8 Number FIGURES (continued) Page 44 The relationship between rate of change in length (cm/day) and river kilometer for age 1+ steelhead in Mean length of age 1+ steelhead in the Rogue River by river kilometer in June, August and October, Weekly catch/unit effort of age O+ steelhead at Sand Hole, Table Rock and High Banks in Weekly catch/trap hour of age O+ steelhead at Savage Rapids trap in 1976 and Weekly catch/seine haul of age 0+ steelhead at stations from km 140 to 183 in Weekly catch/seine haul of age O+ and 1+ steelhead in the Illinois River in Weekly catch/seine haul of age 0+ steelhead at Copelands in the Applegate River in 1976 and Weekly catch/trap hour of age 1+ steelhead at Table Rock and Savage Rapids in 1976 and Weekly catch/seine haul of age 1+ steelhead at Whiskey Bar, Long Gulch and Illahe in Weekly catch/seine haul of age 1+ steelhead at Agness, Hideaway and Canfield in Weekly catch/seine haul of age 2+/3+ steelhead at Agness, Hideaway, Canfield and Mail Boat Point in Weekly mean length of yearling coho salmon at Table Rock trap in Weekly catch/seine haul of yearling coho salmon at Agness, Hideaway and Canfield in Weekly catch/unit effort of juvenile coho salmon at Big Butte Creek, Table Rock and Savage Rapids in Monthly length frequencies of cutthroat trout seined at all estuary stations combined in 1974 and Monthly length frequencies of cutthroat trout seined at all estuary stations combined in 1976 and vi

9 Number FIGURES (continued) Page 60 Weekly catch/seine haul of cutthroat trout at Mail Boat Point in vii

10 Number TABLES Page 1 Location, period and frequency of sampling for juvenile salmonids in the Rogue River during Location, period, frequency and gear for sampling of juvenile salmonids in Rogue River tributaries during Date after which mean length of juvenile chinook salmon continuously exceeded 4.5 cm during 1975, 1976, and Predicted and observed dates of first emergence of juvenile chinook salmon at Sand Hole for Regressions of Julian day on circuli number from juvenile chinook salmon scales collected at Canfield from 1974 through 1976 and Table Rock in 1975 and 1976, and predicted mean dates of fry emergence Regressions of mean length (y) of juvenile chinook salmon on Julian day (x) at main stem and tributary sampling station during Regression of mean length (y) on Julian day (x) for weekly branded groups of juvenile chinook salmon from Lobster Creek recaptured in the Rogue River in Regression of log weight (y) on log length (x) of juvenile chinook salmon at all permanent sampling stations in Monthly mean condition factors of juvenile chinook salmon at Long Gulch and Matson in Average catch/seine haul of juvenile chinook salmon from June through October at permanent sampling stations in Percentage retention and fading of "T' cold brands on juvenile chinook salmon held in live cages in the Applegate River Percentage retention and fading of "E" and "J" cold brands on juvenile chinook salmon held at Cole Rivers Hatchery Days to 70% reduction from peak recapture rate of each group of juvenile chinook salmon branded in Lobster Creek in v i i i

11 Number TABLES (continued) Page 14 Best multiple regressions of migration rate on environmental variables for juvenile chinook salmon recaptured at Savage Rapids trap in Best multiple regressions of migration rate on environmental variables for juvenile chinook salmon branded at Table Rock and Savage Rapids and recaptured below km 45 in Summary of relationships between migration rate and independent variables for all groups of branded fish in 1975 to Mean monthly gill (Na+K)-ATPase specific activity in juvenile chinook salmon by length classes at 1 cm intervals Effects of crowding and starvation on growth and gill (Na+K)-ATPase specific activity in juvenile chinook salmon Gill (Na+K)-ATPase specific activity of juvenile chinook salmon branded May and recaptured at Canfield in Lengths and gill (Na+K)-ATPase specific activities of juvenile spring chinook released from Cole Rivers Hatchery (Na+K)-ATPase specific activity of various organs from a juvenile spring chinook salmon Regressions of Jul ian day (y) on circuli number (x) from scales of age O+ and 1+ steelhead at Agness and the Illinois River from 1974 to Regressions of mean length (y) on Julian day (x) for juvenile steelhead by age class in Analysis of covariance between 1976 and 1977 for regressions of mean length of age O+ steelhead on Julian day at three upper river stations Regressions of mean length (y) on scale radius (x) of age 0+ and 1+ steelhead at Agness and the Illinois River for 1974 to ix

12 Number TABLES (continued) Page 26 F tests from analysis of covariance between 1974 and 1975 regressions of mean length on scale radius for juvenile steelhead at Agness and the Illinois River Calculated mean length at first scale annulus of age 1+ steelhead captured at Agness and the Illinois River during 1974 to Regressions of log weight (y) on log length (x) of juvenile steelhead by age class at permanent stations in Monthly mean condition factor of juvenile steelhead by age group in Mean annual catch/effort of juvenile steelhead by age class in 1975 to Mean length of yearling coho captured in 1975 to Monthly mean condition factor of yearling coho salmon in 1975 to x

13 INTRODUCTION The purpose of this report is to present findings from our studies of juvenile salmonids in the Rogue River during Some data from laboratory studies of parr-smolt transformation and from scale analysis prior to 1977 are reported for the first time. Data from each of the projects within the Rogue Evaluation Program have been integrated into a single results section to improve the continuity of the report. Scale data from 1977 have not been fully analyzed and will be presented in a later report. METHODS Juvenile salmonids were sampled in 1977 by beach seine and trapping at similar times and locations to 1976 (Table 1). Temporary seining stations reached by jet sled were reduced during the summer to five in the upper river and four in the lower river. Seining and trapping were also conducted on several tributary streams (Table 2) to aid in interpreting data from the main stem. Locations of permanent sampling stations and river kilometers are shown in Fig. 1. Sampling methods were similar to those described in the June 1976 Annual Report. Chinook Emergence RESULTS An index of emergence timing for chinook fry was determined by the date after which the average length of fry continuously exceeded 4.5 cm.. This index indicated emergence in 1977 was generally 1-2 wk earlier than in 1976 and 1 mo earlier than in 1975 (Table 3). Emergence in the Applegate River was approximately 1 mo earlier than in Emergence at Sand Hole and Big Butte Creek in 1977 appeared to be several weeks later than all other stations. As in 1976, the date of peak catch/seine haul at both of these stations was actually prior to the date the average length continuously exceeded 4.5 cm. We believe the late mean emergence index at these stations was caused by a protracted outmigration of emerging fry. The timing of first capture of chinook fry by seining at Sand Hole from has corresponded reasonably well to the first emergence date predicted from incubation temperatures (Table 4). Date of emergence was predicted on the basis of 1,800 degree days from first spawning. The date of first spawning was determined by observation of the first carcasses minus 7 days to account for delay from egg deposition to spawning mortality. There was less than a 1 wk difference between predicted and observed emergence from 1976 and 1977 spawning, and a 3 wk difference in

14 Table 1. Location, period, and frequency of sampling for juvenile salmonids in the Rogue River during Station locations Period Sampling (km from river mouth) sampled frequency Upper river permanent stations (253, 209) Jan. Mar. Aug. 7 to Feb to Aug to Dec. 8 biweekly weekly biweekly Table Rock Trap(216) Mar. 1 to Aug. 30 continuous Middle river permanent stations (183, 148, 116) Jan. 3 to Dec. 23 weekly Lower river permanent stations (44, 24, 8) Jan. Mar. 1 to Mar to Nov. 22 biweekly weekly Estuary permanent stations (3, 1, 0.4) Mar. 15 to Nov. 25 weekly Canyon stations (105, 80, 53) Savage Rapids Trap (173) Upper river jet sled stations (167, 158, 152, 140, 136) Lower river jet sled stations (18, 16, 15, 13, 11, 8, 7) Lower river jet sled stations (35, 27, 18, 7) Mar. 5 to Oct. 5 May 31 to Sept. 28 Mar. 25 to Oct. 13 Apr. 15 to June 31 July 1 to Oct. 27 biweekly 5 days/wk weekly weekly weekly 2

15 Table 2. Location, period, frequency, and gear for sampling of juvenile salmonids in Rogue River tributaries during Tributary Distance above Rogue mouth (km) Stat ion name Tributary (km) Period sampled Sampli ng frequency Gear tvpe Big Butte Cr. 250 Big Butte Cr /7 to 2/28 3/1 to 8/30 8/31 to 12/8 biweekly weekly biweekly seine Applegate R. 152 McKee Dam Bridgepoint Murphy Copeland Copeland /4 to 10/13 4/19 to 10/13 3/16 to 6/14 3/1 to 7/8 4/14 to 5/25 biweekly weekly weekly weekly 5 days/wk seine irrigation trap seine seine incline plane trap Illinois R. 44 Illinois R /1 to 10/27 weekly seine Lobster Cr. 18 Lobster Cr /15 to 7/11 5 days/wk incl ine plane trap Lobster Cr. weir 0.5 6/6 to 8/10 5 days/wk weir & trap

16 * SAMPLING STATION i-i 10 KM INTERVAL MARKERS I I-/ / -- - a\x "I -- LCRELK - J ~~~DAM _ v I I. EK I \ IE APPLEGA \ RIVER ( Fig. 1. Locations of permanent sampling stations for juvenile salmonids in the Rogue basin.

17 Table 3. Date after which mean length of continuously exceeded 4.5 cm during 1975, juvenile chinook salmon 1976, and Year and date Station km Sand Hole 253-5/30 5/17 High Banks 209 5/23 4/27 4/19 Matson 148 5/15 4/13 4/4 Almeda 116 5/15 4/27 4/25 Long Gulch /20 Agness 44 5/20 4/21 4/6 Hideaway 24 5/29 4/21 4/28 Canfield 8 5/29 5/6 4/28 5/23 5/10 5/5 4/22 Big Butte Creek Illinois River /30 5/28 Lobster Creek (trap) 18 6/3 Applegate (Copeland trap) 152-5/28 5/9 5/25 4/18 Applegate (Copeland seine) 152-5/16 4/4 Table 4. Predicted and observed dates of first emergence of chinook salmon at Sand Hole for juvenile Predicted Observed First first first spawning emergence emergence 8/31/75 2/14/76 3/7/76 9/6/76 2/26/77 3/1/77 9/19/77 1/22/78 1/17/78 Emergence timing of chinook fry has also been determined from scale analysis for Data from 1977 will be presented in a later report. The intercept in the regression of Julian day on circuli count represents the date of first scale formation, which should be similar to the date of emergence from the gravel. These regressions, determined from juvenile chinook scales collected at Table Rock in 1975 and 1976 and Canfield from 1974 through 1976, are presented in Table 5. The time of emergence predicted from scales was earlier in each year than the time at which lengths exceeded 4.5 cm. This was expected, since the latter actually measures the completion of emergence. Since spawning of adults is spread over a 2 mo period, the mean emergence date should occur several weeks prior to completion of emergence. The wider confidence intervals for mean emergence date at Table Rock suggests that emergence was more protracted in the upper river than in the lower river. This probably resulted from warmer water temperatures in the lower river which reduced incubation timing and, therefore, the period of emergence. 5

18 Table 5. Regressions of Julian day on circuli number from juvenile chinook salmon scales collected at Canfield from 1974 through 1976 and Table Rock in 1975 and 1976, and predicted mean dates of fry emergence. Period Predicted date 95% conf. Year Station sampled Regression line R 2 of emergence interval 1974 Canfield 6/25 to 7/23 JD=i circ /10 5/25 to 6/ Canfield 3/18 to 7/15 JD= circ. o.845 5/15 5/1 to 5/ Canfield 5/6 to 6/26 JD= circ /26 4/11 to 5/ Table Rock 5/5 to 10/7 JD= circ /26 2/9 to 5/ Table Rock 4/11 to 10/11 JD= circ /26 1/30 to 5/20 an

19 Growth Changes in length through time. Mean lengths of juvenile chinook at nearly all stations in the upper and middle river were greater in April and May of 1977 than in past years (Figs. 2-4). The rate of increase in length in the spring was again greater than in the summer. The larger lengths in the spring than previous years appear closely related to the earlier emergence. Average lengths in the spring of 1977 were similar to past years at Sand Hole (Fig. 2), the Rogue River below Almeda (km 116) (Figs. 5-8) and Lobster Creek (Fig. 9), where emergence timing was also similar to past years. Average lengths increased very slowly after mid June at stations from Savage Rapids (km 173) downstream such that average lengths in September were generally smaller than in 1974 and The greater rate of increase in length through the summer from Sand Hole (km 253) to High Banks (km 209) probably resulted from better temperatures for rearing than at stations downstream. The usual sharp decrease in slope of the average length vs Julian day plots in early summer was again evident from Almeda (km 116) downstream (Figs. 4-8). However, early downstream migration caused the change from the sharp slope in spring to the flatter summer slope to occur earlier in the year. This was most evident at Canfield (km 8) and Hideaway (km 24) where lengths increased approximately 3 cm in I and 2 weeks, respectively. A steep spring slope on the average length vs Julian day plots also occurred at High Banks (km 216) (Fig. 2), but not at Matson (km 148) (Fig. 4). As found in 1976 (March 1978 Progress Report), the flattening of the slope at High Banks occurred later (early July) than at Almeda (mid May) and followed the outmigration of juvenile chinook from upriver as indicated by decreasing catch/effort at Table Rock trap (km 216) (Fig. 21). A change in slope did not occur downstream at Matson, probably due to a continual immigration of juveniles from the Applegate River (km 152). It is possible that the decrease in slope of the average length vs Julian day plot at High Banks was caused by emigration of larger than average fish. This thesis is supported by data from juvenile chinook scales collected at Table Rock trap. Reimers (1973) related the widths of bands of five consecutive circuli from juvenile chinook scales to growth rate during the period the scales were formed. There was an irregular yet distinct decrease in the width of both the first and second bands of five intracircular spaces on juvenile chinook scales at Table Rock from June to November in 1975 and 1976 (Fig. 10) (data from 1977 are not yet analyzed). This demonstrates that faster growing fish in the upper river generally migrate downstream earlier than slow growing fish. Average lengths of juvenile chinook in Big Butte Creek, the Illinois River, and the Applegate River were also larger in April and May of 1977 than in 1976 (Figs. 11 and 12). The greatest difference occurred in Big 7

20 I0. 8 SAND HOLE KM 253 () 6 co 1-- D ẕ J 10 z U 8 HIGH BANKS KM L Fig APR OCT Weekly mean length of juvenile chinook salmon at Sand Hole and High Banks in 1975, 1976 and

21 0 10- TABLE ROCK KM ' J UJ z wj 10 8 I I I I I I SAVAGE RAPIDS KM 173 APR' MAY I JUN I JUL I AUG ' SEP ' OCT Fig. 3. Weekly mean length of juvenile chinook salmon and at Table Rock and Savage Rapids Dam in 1976

22 MATSON... _ E^~~K 14 % W - 8 K W 8-6 APR Fig. 4. Weekly mean length of juvenile chinook salmon at Matson and Almeda in 1975, 1976 and 1977.

23 8- WHISKEY BAR KM 105 -_ ) 6-1- z -J z Ld I I I,. 1 I WINKLE BAR KM APR' MAY JUN JUL AUG SEP IOCT' Fig. 5. Weekly mean length of juvenile and chinook salmon at Whiskey Bar and Winkle Bar in 1975, 1976

24 10 8- AGNESS KM (9 Id z IdJ HIDEAWAY KM APR' MAY ' JUN' JUL ' AUG ' SEP ' OCT I Fig. 6. Weekly mean length of juvenile chinook salmon at Agness and Hideaway in 1976 and 1977.

25 IA F z 77 z JUL Fig. 7. Weekly mean length of juvenile chinook salmon at Canfield from 1974 to 1977.

26 MAIL BOAT POINT KM I- (9 -J z Lu I I I I I I COAST GUARD KM 0.9 APR' MAY ' JUN I JUL ' AUG I SEP ' OCT I Fig. 8. Weekly mean length of juvenile chinook salmon at Mail Boat Point and Coast Guard in 1976 and

27 F- z lij I () z w MAY ' JUN ' JUL Fig. 9. Weekly mean length of juvenile chinook salmon at Lobster Creek trap in 1976 and 1977.

28 I OD 00 12A x 1975 I ST BAND II ~~~~~~~~~~~~~1976 1ST BAND 10 9 z m 8 m 8 ND ~~~~~~~~~~~2 BANND JUN JUL AUG SEP OCT Fig. 10. Weekly mean width of bands of five consecutive intracircular spacings on scales from juvenile chinook salmon at Table Rock in 1975 and 1976.

29 10 BIG BUTTE CREEK 0 -r I 8-6- z zw LL~~~~~~I z 10o 8- ILLI 977 wa: 6- APR' MAY JUN I JUL AUG I SEP ' OCT Fig. 11. and Weekly mean length of juvenile chinook salmon in Big Butte Creek and Illinois River in 1976

30 8 MURPHY I 1976 II z 8- COPELANDS 6, MAR ' APR ' MAY ' JUN JUL Fig. 12. Weekly mean length of juvenile chinook salmon at Murphy and Copelands in the Applegate River in 1976 and 1977.

31 Butte Creek where lengths remained approximately 1 cm larger than in 1976 through July. Regressions of average length on Julian day at all permanent stations during 1977 are presented in Table 6. Separate regressions were calculated for the spring and summer at stations where changes in slope were apparent. No regressions prior to June could be calculated for Hideaway (km 24) and Canfield (km 8) because of sudden changes in length in May. Slopes of the average length vs Julian day regressions from the spring period in 1977 at High Banks and Almeda were slightly less than in 1976 (comparisons at other stations between years were not possible). Spring 1977 temperatures at Grants Pass (km 164) averaged 2 to 5 C higher than in 1976 and growth in 1977 should have been enhanced (March 1978 Progress Report). However, spring river flow averaged about one-third of that in 1976 and may have sufficiently reduced the available rearing habitat to affect growth. Earlier downstream migration of the largest juveniles would also have caused the regression slopes to be flatter, but does not appear to have occurred (see Migration section). Slopes of the average length vs Julian day regressions for the summer period were either similar or slightly steeper than in 1976, but still flatter than in 1974 and Reduced crowding due to earlier outmigration of juveniles (see Migration section) may have improved growth through the summer of This is consistent with the conclusion drawn from the review of data from 1974 to 1976 (March 1978 Progress Report). Water temperatures in 1977 were above average (Appendix 1) throughout the river and were probably above the optimum for growth through most of the summer. While in previous years the Rogue Canyon had the largest juveniles throughout most of the season, 1977 average lengths at canyon stations were among the smallest in the river (Fig. 13). Most of the juvenile chinook sampled in the canyon during 1977 may have been resident fish suffering from the high temperatures and widespread disease rather than larger migrants from up river as was hypothesized in previous years (March 1978 Progress Report). Harsh environmental conditions may have caused migrant fish to move rapidly through the canyon and be less susceptible to capture. Growth rates in the Rogue River of juvenile fall chinook branded in Lobster Creek were obtained in the spring of 1977 (see migration section for details of branding experiment). Growth rates were calculated for each weekly brand group by regressing mean length at capture on Julian day (Table 7). Only weeks when seven or more fish were recaptured were included in these regressions. A clear cut pattern between the slopes of these regressions and mean river temperatures during the period of recapture was not apparent, although large variations in slope did occur. The small sample sizes for these regressions and the influence of large 19

32 Table 6. Regressions of mean length (y) of juvenile chinook salmon tributary sampling stations during on Julian day (x) at main-stem and No. dates km Station Period Regression line sampled R 2 t C 253 Sand Hole 216 Table Rock 6/7 to 8/23 4/12 to 10/8 y= x y=0.0203x o ** 6.92** 209 High Banks 4/12 to 6/28 y= x o ** 183 Valley of Rogue Park 7/5 to 11/1 4/18 to 6/27 y= x y=o.0522x o ** 10.77** 7/5 to 11/7 y= x (NS) 172 Savage Rapids 6/1 to 9/21 y=0.0137x ** 148 Matson 4/11 to 7/11 y=0.0193x ** 7/18 to 11/7 y= x (NS) 116 Almeda 4/25 to 5/23 y=0.0758x ** 6/13 to 10/24 y= x ** 105 Whiskey Bar 4/20 to 5/28 y=0.0570x ** 6/9 to 10/5 y=0.0135x ** 80 Long Gulch 4/20 to 5/29 6/10 to 10/5 y x y=0.0159x ** 18.02** 56 Illahe 4/21 to 6/10 y= x ** 44 Agness 4/15 to 6/9 y= x ** 6/16 to 9/14 y=0.0151x ** 24 Hideaway 6/9 to 9/21 y= x ** 8 Canfield 6/9 to 10/20 y=0.0091x ** 0.2 Coast Guard Station 7/12 to 10/27 y=0.0170x ** 250 Big Butte Creek 4/26 to 7/19 y=0.0517x ** 151 Copeland (Applegate R.)3/10 to 5/23 y= x ** 44 Illinois River 6/2 to 9/14 y=0.0120x ** NS indicates not significant at the p < 0.05 level **indicates significance at the p < 0.01 level.

33 I li AUG z LJ wlj I I I I I I OCT 2-6 I I I I I I I RIVER KM Fig. 13. The mean length of juvenile chinook salmon in the Rogue River by river kilometer for three time periods in

34 fluctuations in abundance may have masked the relationship between growth rate and temperature which was demonstrated for data from 1974 to 1976 (March 1978 Progress Report). Table 7. Regression of mean length (y) on Julian day (x) for weekly branded groups of juvenile chinook salmon from Lobster Creek recaptured in the Rogue River in Mean No. Mean river date Sample dates temperature branded period Regression line sampled R 2 t (C)a/ 4/13 4/11-5/2 y= x ** /20 4/20-5/16 y= x ** /28 4/25-5/16 y=0.0301x ** /12 5/10-5/31 y= x o * /19 5/18-5/31 y= x NS /26 5/24-6/13 y=0.0703x NS /8 6/6-6/27 y=0.0357x ** Mean of daily maximum river temperature at km 9 in Rogue River. **indicates significance at the p < 0.01 level. *indicates significant at the p < 0.05 level. NS indicates not significant at the p < 0.05 level. Growth rates determined from scale analysis. Scale circuli spacing has often been used as an indicator of growth rate. Before making inferences about growth of juvenile chinook in the Rogue River from scale spacings, we wanted to determine the accuracy of this relationship. Accordingly, we sampled 30 scales from each of six groups of juvenile spring chinook reared under different feeding regimes at the Corvallis Laboratory in Growth rates of these groups varied from to cm/day (Fig. 14). Scales sampled on November 1 when fish lengths averaged from 7 to 13 cm showed no significant difference (p < 0.05) in the width of the first band of five circuli spacings, but the widths of the second band were significantly (p < 0.01) correlated to growth rate (Fig. 15). The lack of any differences in the first band was probably due to the small variation in the growth rates of the different test groups for the first 2 mo of the experiment (Fig. 14). By the time the second band was formed, there was a wider range in growth rates. Average scale spacing (total scale radius - nucleus radius) /total circuli number for each of these groups was also significantly (p < 0.01) correlated to growth rate (Fig. 16). The accuracy of this relationship was substantially decreased, however, when regressions were calculated using the values for individuals, rather than the group means (R 2 = compared to R 2 =0.968). These data indicate that scale spacing does increase with growth rate, but caution should be exercised when comparing individual fish. 22

35 I I-,1.75% BODY WT/DAY '2.16% BODY WT/DAY,1.5% BODY WT/DAY 41.25% BODY WT/DAY (-) I- (D -LJ I % BODY WT/DAY,0.76% BODY WT/DAY LUJ 5- J 'F ' M 'A' M ' JJ 'Al S O'N 'D' Fig. 14. Weekly mean length of juvenile chinook salmon reared in the Corvallis laboratory at six different feeding levels in 1976.

36 0 z m 0 z 0 () U) LL 0 w F- (9 z Lu x Ii D Ir 12- IH % CONFIDENCE / ~-~INTERVALS Y= X 2 R = z LuJ C-) 9- IL 0.01 I.02 I.03 I.04 AVERAGE GROWTH RATE CM/DAY Fig. 15. A regression showing the relationship between the mean width of the second band of scale circuli and mean growth rate of chinook salmon reared at the Corvallis laboratory in 1976.

37 ra 0 I a, "I,. 00 x z %-n - Lu (> Li I Y= X R 2 =0.918 T =6.69** % CONFIDENCE INTERVALS AVERAGE GROWTH RATE CM/DAY Fig. 16. The regresssion of mean scale circuli spacing on average growth rate of juvenile chinook salmon reared at the Corvallis laboratory in 1976.

38 CANFIELD 1974 CANFIELD 1975 CANFIELD 1976 GOLD- HILL 1974 TABLE ROC K 1975 TABLE ROCK CD Xo 12-1 I- ElI ST E IST BIST I ST 8IST 8 IST 0o I 0 0 z m H3RD 2ND 5 2 ND H3RD 2ND 8 83RD 2ND H 3 RC 2ND L A L I I 02ND Fig. 17. Means and 95% confidence intervals for band widths of juvenile chinook salmon scales collected at Table Rock, Gold Hill and Canfield in 1974 to 1976.

39 Band widths on scales collected at Table Rock and Canfield indicate that growth rates of juvenile chinook differed among 1974, 1975 and The annual mean width of the first band (closest to nucleus) at Table Rock was larger (p < 0.05) in 1976 than in 1975 (Fig. 17). There was no significant difference in the width of the second band. At Canfield, the width of the first band was significantly larger in 1976 than in either 1975 or Again, there were no differences in the second band width. These data indicate that growth rate during the first 2 mo of rearing was superior in 1976 to 1975 and In contrast, it was concluded from field data that the best growth in June at Canfleld occurred in A plot of the average widths of the first band for each week of sampling at Canfield in 1974, 1975 and 1976 indicates that they were similar at the end of June 1974 and 1976, but were generally smallest in 1974 from July through mid September (Fig. 18). No scales were collected prior to June 25, 1974, so comparisons between 1974 and 1976 cannot be made for earlier portions of the year. It appears that growth rate in the spring of 1974 was certainly not greater than in 1976, and may have been less. This finding has a serious impact on the theory that spring growth rates of juvenile chinook are highly correlated to spring temperatures. Since the warmest spring temperatures from occurred in 1974, warmer temperatures may not be desirable. However, preliminary analysis of juvenile chinook scales in 1977, the warmest water year yet, indicates spring growth was better than in any of the previous years. These findings demonstrate that we do not fully understand the factors which control spring growth rate of juvenile chinook. Band widths of scale circuli also indicate that differences in growth rate may exist between the upper and lower river. The mean width of the first band on scales collected from juvenile chinook at Gold Hill (km 202) in 1974 and Table Rock (km 216) in 1975 was larger than those at Canfield in the same years (Fig. 17). There was no difference in The average width of the second band, however, was greater at Canfield in all 3 yr. It appears the conditions for early spring growth are usually better in the upper river. The smaller widths of the second bands in the upper river may have been caused by outmigration of faster growing fish prior to formation of the second band. Body condition. The fatness of juvenile chinook was analyzed through regressions of log body weight on log length (Table 8). An analysis of covariance between these regressions indicated that differences in slopes were highly significant. 27

40 --,% co 74 aco z m 0 ~10- JUN ' JUL ' AUG ' SEP OCT Fig. 18. Weekly mean width of the first band of five intracircular spaces on scales from juvenile chinook salmon at Canfield in 1974 to 1976.

41 Table 8. Regressions of log stations in weight (y) on log length (x) of juvenile chinook salmon at all permanent ED km Station Period Regression line n R 2 t 253 Sand Hole 6/7 to 8/2 y=3.3219x ** 216 Table Rock 5/29 to 10/4 y= x ** 209 High Banks 5/31 to 10/11 y= x ** 183 Valley of Rogue Park 6/1 to 10/3 y= x ** 173 Savage Rapids 5/31 to 9/15 y=2.7209x ** 148 Matson 5/31 to 10/3 y=2.5170x ** 116 Almeda 5/31 to 10/10 y= x ** 80 Long Gulch 6/10 to 10/5 y= x ** 44 Agness 6/2 to 10/27 y= x ** 24 Hideaway 6/2 to 10/27 y= x ** 8 Canfield 6/2 to 10/27 y=2.9013x ** 2 Mail Boat Point 6/1 to 10/25 y=3.1843x ** 0.9 Coast Guard Station 6/1 to 10/25 y= x ** 250 Big Butte Creek 5/7 to 7/5 y=3.0913x ** 44 Illinois River 6/2 to 10/27 y=3.1901x o ** **indicates significance at p < 0.01 level

42 A plot of the log weight vs log length regression slopes against river kilometer from 1975 through 1977 (Fig. 19) shows once again that the flattest slope was at Long Gulch in the mid canyon (km 80), and that slopes at Matson and Savage Rapids were flatter than previous years. At each of these stations, the regression intercept values were higher on the y-axis than at other stations, indicating fatter small fish in the spring. Larger juvenile chinook captured at these stations later in the summer were less fat causing a reduction of the regression slopes. This decrease in body condition throg' h the summer was evident from the monthly mean condition factor (Z(Wt/L xloo) at Long Gulch and Matson (Table 9). n A comparison of body condition between stations and years can also be made by considering the weight of a hypothetical 8 cm chinook calculated from the log weight vs log length regression (Fig. 20). The weight of this hypothetical fish would have been greatest from Savage Rapids Dam upstream in 1977, and greatest below Savage Rapids Dam in The high condition of 8 cm fish in the upper river in 1977 most likely reflects improved rearing conditions, due to warmer than normal summer temperatures. Summer river temperatures in the upper Rogue are normally below the optimum for rearing. The high condition of 8 cm chinook below Savage Rapids Dam in 1975 reflects the cooler summer river temperatures than normal and lower population densities that existed in Summer temperatures in the middle and lower river are normally above the optimum for rearing. Table 9. Monthly mean condition factors of juvenile chinook salmon at Long Gulch and Matson in Long Gulch Matson Mean condi- Mean condi- Month tion factor!/ S.D. n tion factor S.D. n June o.o July August September October aimean condition factor = E(WIL3 x 100) n An additional difference among years, in the weight of an 8 cm chinook,occurred at the Coast Guard Station in the estuary. These fish were much heavier in 1975 than in 1976 and This difference is probably due to the size at which fish entered the estuary. Juvenile chinook captured in the estuary in 1975 were larger than in 1976 or 1977 and were likely more physiologically adapted to the change from fresh to 3a

43 '~~~~~~~ RIVER KM Fig. 19. The relationship between slope from the regression of loglo weight on loglo length of juvenile chinook salmon and river kilometer in Ldi qv7.0oi W a.8 im> r W w w W r X ido l 140 RIVER Fig. 20. The relationship between the weight of a hypothetical 8.0 cm juvenile chinook salmon calculated from the regression in Table 8 and river kilometer in KM

44 salt water. This would have produced a regression line with a high y- intercept, even though few fish as small as 8 cm were included in the sample. In 1976 and 1977, large numbers of juvenile chinook entered the estuary at a length which would likely have left them less prepared physiologically for the transition from fresh to salt water, and this would account for their decrease in body condition. Distribution and abundance Distribution of chinook juveniles has been deduced from the average annual catch/seine haul at permanent stations (Table 10). Average annual catch/seine haul was calculated for the period June 1 to October 31 to coincide with the period during which most of the juvenile chinook rear and migrate to sea. Table 10. Average catch/seine haul of juvenile chinook salmon from June through October at permanent sampling stations in Catch/seine haul by year Station km South Jetty Coast Guard Mail Boat Point Canfield Hideaway Agness Illahe Winkle Long Gulch Whiskey Almeda Matson Savage Rapidsa/ Hi.gh Banks Table Rock-/ Sand Hole Big Butte Creek Illinois River Bridgepoint /Data reported in catch/trap hour. The greatest density of juvenile chinook in the upper river was at Sand Hole (km 253) in 1977 compared to High Banks in Abundance was high at these stations only in May and June in both years. The reduced river flows in the spring of 1977 may have permitted greater numbers of emergent fry to resist downstream drift causing peak abundance to occur further upstream. 32

45 In the middle and lower Rogue River in 1977, average annual seine catches were well below those recorded for The 1977 catches at Matson and Almeda were lower than any previous year. Two factors influenced these low catches. First, downstream migration of juveniles in the upper and middle river occurred earlier in 1977 than in previous years (see Migration section), resulting in low catches throughout the summer and fall. Secondly, high temperatures and low flows during the summer of 1977 (Appendices 1 and 2) caused large numbers of juveniles to congregate at the mouths of cool water tributaries where they were not available for capture. Traps monitoring downstream migration of juvenile chinook at Table Rock (km 216) and Savage Rapids showed larger average annual catches in 1977 than in previous years. Because of low flows, these traps sampled a larger proportion of the river than in previous years. The increased efficiency of the Savage Rapids trap is reflected in the improved recapture rate of juvenile chinook branded at Table Rock, from 0.21% in 1976 to 0.94% in The catch of juvenile chinook at Bridgepoint trap (km 39) in the Applegate River dropped to zero in Low flows in the fall of 1976 severely limited passage of adult chinook over Murphy Dam (km 19), which resulted in the absence of juveniles in the normal rearing areas above that point. The distribution in the Rogue of juvenile fall chinook from the Applegate River in 1977 was studied by cold branding juvenile chinook in the Applegate River at Copeland's (km 0.4). A total of 13,256 juvenile chinook were marked between March 14 and June 3. Eight sampling stations in the Rogue River between the mouth of the Applegate River (km 152) and Almeda (km 116) were seined weekly during this period to recapture marked fish. Rogue canyon stations and lower river stations were also seined at the standard frequency (Table 1). Sixty marked fish were recovered between the mouth of the Applegate River and Almeda; however, only four were recovered below Almeda. Of the 60 marks recovered between the mouth of the Applegate and Almeda, only one fish was recaptured more than 3 wk after marking. These data suggest that juvenile chinook from the Applegate moved slowly downstream and their brands were completely faded before they reached the lower 44 km of the Rogue. A mark retention experiment was conducted to determine how long the "T" brand used on the Applegate chinook fry remained visible. Mark retention was examined for three sizes of chinook juveniles (<6 cm, 6.1 to 7.5 cm, and 7.6 to 9.0 cm) and also for anterior and posterior locations on the fish. All groups were marked on May 27. Brands did not fully darken for at least 1 wk. Anterior marks on all three size groups began to fade rapidly 33 to 40 days after marking (Table 11). The smallest group of fish (<6.0 cm) lost their marks before the two larger groups of chinook juveniles. Although the majority of marks in the group of small fish remained clear through the first month as in the larger groups, 33

46 Table 11. Percentage retention and fading of "'T" cold brands on juvenile chinook salmon held in live cages in the Applegate River. Group 1 < 6.0 cm Days after Condition of anterior mark marking Gone Faded Clear Sample size % 92% 99% 58% 4% 5%/ 1 3% 14% 60% 143% 8% 1 % 42% 96% 95% 87% 85% 39% 0% 0% 0% Group to 7.5 cm Days Condition of marks after Anterior Posterior Sample marking Gone Faded Clear Gone Faded Clear size % % 98% 0 2% 98% % 98% 0 5% 95% % 92% 0 8% 92% % 10% 88% 2% 38% 60% % 49% 48% 10% 85% 5% % 59% 15% 92% 8% % 49% 0 100% % 11% 0 100% Group to 9.0 cm Days Condition of marks after Anterior Posterior Sample marking Gone Faded Clear Gone Faded Clear size % % % 63% 0 49% 51% % 98% 0 9% 91% % 2% 96% 0 23% 77% % 5% 93% 2% 52% 45% % 20% 77% 25% 70% 5% % 68% 20% 95% 5% % 42% 0 98% 2% % 12% 0 100% 0%

47 they faded quickly within the next 2 wk. The marks of the two larger groups also began to fade after 1 mo but took longer to completely disappear. Posterior marks in the two groups of larger fish disappeared more rapidly than anterior marks. Most posterior marks began fading 26 to 33 days after marking and had disappeared after 47 days. A second cold brand retention experiment was conducted in the fall of 1977 using chinook from Savage Rapids trap. These fish were larger than the Applegate juveniles, averaging 9.5 cm, and were marked with a much larger brand. Two brands were compared for retention timing, an ''E" and a "J". Size dimensions of the brands and results of the retention experiments are given in Table 12. Although all "E" and "J" marks were still visible 60 days after branding, the thicker "J" mark remained clear on 57% of the fish compared to only 17% of the "E" marks. All of the thin "T" marks were unclear after 50 days, and 88% of the marks had completely disappeared (Table 11). Future marking should be done with the thickest possible brands. Table 12. Percentage retention and fading of "E" and "J" cold brands on juvenile chinook salmon held at Cole Rivers Hatchery. Days after Condition of "E" mark Sample Condition of "J" mark Sample marking Clear Faded Gone size Clear Faded Gone size 13 75% 25% % 16% % % % % % 57% % 30% % 83% % 43% 0 23 Although juvenile chinook were marked in the Applegate River, and at Savage Rapids and Table Rock traps, the recaptures were not used for population estimates. Results of mark retention experiments in 1976 (March 1978 Progress Report) and 1977 indicate these estimates would not be accurate. Migration Migration timing. The downstream progression in timing of peaks in catch/effort in 1977 suggests that the major outmigration of juvenile chinook occurred in June. It was noted in past years that the initial migration of juvenile chinook throughout the river began in June (January 1977 and March 1978 Progress Reports); however, chinook remained in abundance in the middle and lower river through the summer. In 1977, catch/seine haul had declined 5 to 10 fold by mid July at nearly all stations and catches remained low for the rest of the summer. It appears that good spring growth, high abundance, and poor summer rearing 35

48 conditions caused the great majority of juvenile chinook to migrate out of the river in June. Catch/effort peaked in mid May at Sand Hole (km 253) and High Banks (km 209) and mid June at Table Rock (km 216) (Fig. 21). This timing was similar to past years. The decreasing catches after mid May at Sand Hole and High Banks suggest that the June peak in catch at Table Rock trap represents fish migrating out of the upper river. These fish would normally have caused peak catches at Savage Rapids trap (km 173) in late July or August. Catch at Savage Rapids peaked the week of June 6 (Fig. 22), 1 wk earlier than catches upstream at Table Rock (Fig. 21). Many of the chinook passing Savage Rapids the week of June 6 must have originated below Table Rock. Sharp declines in catch from Matson (km 148) to the estuary generally occurred in June (Figs ). Sharp increases in mean length at Hideaway and Canfield (Figs. 6 and 7) verify that these decreases represent migration of chinook out of the middle and upper rivers while mean lengths in the middle river in late May were from 7.5 to 8.5 cm, they were approximately 5 cm in the lower river. Mean lengths increased at Canfield from 5.2 cm on May 26 to 8.6 cm on June 2 and at Hideaway from 5.2 cm May 19 to 7.9 cm on June 2. Deviations from the general timing of peak catches occurred at Agness (km 44) and Coast Guard (km 0.9). We believe that the main concentrations of juveniles at Agness in June were holding off the mouth of the cooler Illinois River, just across the river from the seining site. This was confirmed by the observation of massive schools of both juvenile and adult chinook at the mouth of the Illinois River. Catches at Coast Guard are strongly influenced by salinity changes and are subject to high variation, so the peak catch in early August was probably due to chance. Catches in Big Butte Creek and the Applegate River also peaked slightly earlier than in past years. Catch in Big Butte Creek peaked at the end of March in 1977 (Fig. 27) compared to mid April in 1976 (March 1978 Progress Report). Catches at Murphy and Copelands on the Applegate River peaked in mid April and early May, respectively in 1977 (Fig. 27) compared to early May and late May, respectively in 1976 (March 1978 Progress Report). Catches declined more rapidly following these peaks than in past years, probably as a result of fish moving rapidly downstream in response to low flow. The movement of chinook out of the Applegate also appears to have caused decreases in the average length at several stations in the Rogue. Following the peak migration out of the Applegate in late May, average lengths at Flannigan Slough (km 140) and Almeda (km 116) decreased from above 8 cm to 7.5 cm, similar to those captured in the Applegate. Catch in the Illinois River peaked in June, and an additional peak occurred in July (Fig. 28). Catches also did not drop as rapidly to low levels as in the main stem. These differences may in part have been caused by juvenile chinook from the Rogue River swimming up the Illinois 36