Seaward Migration To go or not to go? Timing Locomotion Life history patterns Environmental changes Chinook salmon smolt
Because streams in our region are unproductive, salmonids face a fundamental dilemma each year: stay, grow slowly but be safe, or go to sea, grow fast, and face the sharks! G. Ruggerone
Annual Dilemmas Go to Sea Stay in Freshwater Mature Remain Immature Mature Remain Immature Timing: 1. Go this year? 2. What time of the year? 3. What date? 4. What time of day or night?
Hypothesized costs and benefits of freshwater residence for juvenile survival 1.0 Freshwater survival Marine survival 0.14 Proportion surviving to enter sea 0.8 0.6 0.4 0.2 Freshwater age 0 Freshwater age 1 Freshwater age 2 0.12 0.10 0.08 0.06 0.04 0.02 Mariine survival 0.0 25 35 45 55 65 75 85 95 105 Fork length (mm) 0.00
Timing of Seaward Migration 1. Internal Endogenous 2. Photoperiod: Zeitgeber 3. Temperature: Stimulus 4. Genetic Variation 5. Condition of the Fish rhythm Size Growth rate Fatness (weight/length ratio)
Conservation issues related to seaward migration Mortality Concerns about mortality in general Losses associated with dams and other human activities Changes in Selection on Life History Traits We have increased the costs of migration by mortality associated with dams and fishing but we have not increased the benefits of anadromy Environmental Changes Climate-related changes in flow and temperature regimes Hydrologic changes from hydroelectric development Growth patterns in hatcheries differ from those of wild fish Predation pressure from non-native fish
Evaluating Life History Patterns Goal: Maximize the number of viable offspring over one s life Semelparous Animal: Probability of surviving to maturity. Reproductive success at maturity. Iteroparous Animal: Summed probability of reproductive success for each age, and probability of surviving over the entire lifetime. Each life history decision has consequences for survival, growth, and therefore lifetime reproductive success.
Fitness = W Where W = Σ l x * b x l = probability of survival and b = reproductive success Summed over all ages (x) Anadromy increases the fish s potential reproduction (because growth increases fecundity, etc.) but decreases the probability of surviving to realize that potential.
Techniques for studying downstream migration Numerous nets, traps, weirs, counting boards, acoustic devices and other techniques have been devised to quantify the timing and magnitude of downstream migration Trap efficiency typically varies with fish size, species, flow, time of day, etc. and careful calibration is needed if data are to be reliable.
Inclined plane or scoop trap
Screw trap Downstream trapping methods
Fan trap, Forks Creek, Washington
Fyke net
Seining in Shilshole Bay
Typical (++) and less common (+) smolt ages 0 1 2 3 4 5 6 7 8 Pink salmon ++ Chum salmon ++ Chinook salmon ++ ++ + Coho salmon + ++ ++ + Masu salmon ++ ++ + Steelhead trout + ++ ++ + Cutthroat trout + ++ ++ ++ + + Dolly Varden + ++ ++ + + Arctic charr + + ++ ++ ++ ++ + +
Intra-specific patterns: Smolt age is positively correlated with latitude and negatively correlated with growing conditions For example, yearling chinook are virtually the only type to occur north of 56 N latitude, and in southern areas they are more common at high altitudes
Chinook, age 1+, ~ 120 mm Cedar chinook 1+ smolt Chinook, age 0+, ~ 80 90 mm Cedar coho smolt
Steelhead smolts tend to be older at higher latitudes Smolt age Alaska (6) B.C. (15) WA (9) Columbia River (18) Oregon (4) California (8) 1 0 1 6 4 4 23 2 15 35 86 79 79 69 3 74 61 8 17 16 7 4 11 4 0 1 1 1 Busby et al. 1996 NOAA-NMFS Steelhead status review
Older smolts are not necessarily larger (e.g., steelhead sampled at Rock Island Dam) 185 fork length (mm) 175 165 155 0.7% 43.2% 46.4% 8.6% 1.0% 145 1 2 3 4 5+ steelhead smolt age Peven et al. (1994)
Patterns among populations: Some habitats produce faster growing salmon than others, because of temperature, primary and secondary production, competition, etc. In some cases this results in differences in smolt age but in other cases smolts go to sea at very different sizes, reflecting different ecological pressures
Average population-specific 40 lengths of age 1 smolts % of populations 30 20 10 sockeye (n = 85) coho (n = 117) 0 50 70 90 110 130 150 Smolt length (mm)
Average age composition, size, and marine survival of sockeye smolts from Bristol Bay Lake system Years Smolt age Survival Weight % at age Iliamna 1976-93 1 7.5 6 53 2 11.9 9 47 Becharof 1982-93 1 18.4 10 29 2 28.6 14 71 Ugashik 1982-93 1 4.9 7 51 2 10.0 11 49 Wood River 1975-90 1 6.0 7 93 2 6.9 9 7 Alaska Dept. of Fish and Game data, summarized by Gregory Ruggerone, NRC Inc.
Patterns among years within populations: Smolt age within a given population varies with growing conditions For example, higher density or lower temperature can reduce growth and increase the average smolt age
Iliamna Lake sockeye salmon 100 % age 1 smolts 80 60 40 20 0 r 2 = 0.54 40 50 60 70 mean fry length on 1 September
Timing patterns among populations: Smolt migration is generally earlier in the year in the south and later in the north, matching local conditions Northern populations also tend to migrate over a narrower period each year, and vary less among years than southern ones Internal rhythms and photoperiod combine to produce population-specific patterns of readiness for seaward migration
Relationship between latitude and median date of downstream migration of various populations and species Month Feb. Mar. Apr. May. Jun. Jul J.-G. Godin. 1982. In: Brannon and Salo 35 40 45 50 55 60 65 70 Latitude o N
3,500 Timing of chum salmon downstream migration in the Skagit River, 2006 (WDFW data) 3,000 2,500 Median: 6 April 2,000 1,500 1,000 500 0 22-Feb 15-Mar 5-Apr 26-Apr 17-May
Smolt timing varies among species 80 (e.g., Columbia River) % of annual total 60 40 20 0 coho chinook sockeye steelhead 1 2 3 4 5 6 7 8 9 10 11 12 months of the year
100 chum: median = 6 April Cumulative % migration by salmon and trout in the Skagit River (2006: WDFW data) 50 0 pink: median = 14 April 2-Feb 22-Feb 14-Mar 3-Apr 23-Apr 13-May 2-Jun 22-Jun 100 50 0+ Chinook: median = 30 March coho: median = 16 May 0 2-Feb 22-Feb 14-Mar 3-Apr 23-Apr 13-May 2-Jun 22-Jun 100 steelhead: median = 22 May 50 cutthroat: median = 31 May 0 2-Feb 22-Feb 14-Mar 3-Apr 23-Apr 13-May 2-Jun 22-Jun
Timing patterns among years with populations: Migration is often earlier after a warm spring 14-Jun 7-Jun Median migration date of Kvichak River sockeye salmon 31-May 24-May 17-May 0.0 2.0 4.0 6.0 8.0 10.0 12.0 June 1-15 water temperature
Smolt migration is early after a warm spring: Umpqua River Chinook salmon Median migration date 24-Jul 24-Jun 25-May 25-Apr Umpqua River Jackson Creek Roper and Scarnecchia 1999 6 10 14 18 Average spring water temperature
Older and larger smolts leave before smaller ones Percent of age 2 (rather than age 1) sockeye smolts and average length of age 2 smolts 1990: Iliamna Lake, AK 100 115 % age 2 smolts 75 50 25 % age 2 length 110 105 100 mean length (mm 0 95 22-May 29-May 5-Jun 12-Jun
Smolt fork length (mm) Older and larger smolts tend to migrate earlier than smaller ones: Big Beef Creek coho salmon 160 140 120 100 80 60 40 20 0 50 70 90 110 130 150 170 Day of the year
Downstream migration reflects changes in behavior: loss of territoriality, and downstream orientation % of juvenile ocean-type chinook showing downstream movement in experimental tanks % downstream movement 50 40 30 20 10 0 25-Mar 14-Apr 4-May 24-May 13-Jun 3-Jul Whitman 1987
Migration downstream tends to be at night: Lakelse River system, B.C. % of catch for each species 36 24 12 0 sockeye coho pink 21:00 23:00 1:00 3:00 5:00 Hour ending McDonald 1960
Smolts starting farther upriver migrated faster than those starting downriver: age 0 Chinook salmon Travel rate (km/day) 40 35 30 25 20 15 10 5 0 Dawley et al. 1986 0 200 400 600 Km from release site to Jones Beach
Smolts released later migrated faster than those released earlier: coho smolts going 462 km down the Snake and Columbia rivers 50 Travel rate (km/d) to Jones Beach 45 40 35 30 25 20 15 10 5 0 1967 1968 5-Mar 25-Mar 14-Apr 4-May 24-May Date of release at Ice Harbor Dam
Larger smolts may travel faster than smaller ones: Little White Salmon Hatchery chinook Rate of movement (km/day) 30 25 20 15 10 50 60 70 80 Mean fork length (mm)
Travel rate of Chinook salmon smolts from the UW hatchery to the Ballard Locks in 2006 25 Days from UW to locks 20 15 10 5 0 60 70 80 90 100 110 120 130 140 Fork length (mm)
Chinook salmon smolts released later in the season migrated faster from the UW hatchery to the Ballard Locks Year Release date Travel rate (days) 2006 6 May 14.3 2007 15 May 10.7 2008 30 May 6.1
Back on the Columbia River Relationship of flow to smolt travel time Log average travel time per project (days) 2.4 2.0 1.5 1.2 0.8 0.4 0 chinook steelhead 3.0 3.4 3.8 4.2 4.6 5.0 5.4 Log of flow at Ice Harbor Dam (cfs) Sims and Ossiander 1981. NMFS Report to Corps of Engineers
Relationship of flow to smolt survival Log average survival per dam 4.75 4.50 4.25 4.00 3.75 3.50 chinook steelhead 3.0 3.4 3.8 4.2 4.6 5.0 5.4 Log average flow at Ice Harbor Dam (cfs) +/- 7 days of peak migration Sims and Ossiander 1981. NMFS Report to US Army Corps Engineers
Average June flow at Bonneville Dam 700 600 flow (kcfs) 500 400 300 200 100 0 1944 1964 1984 2004 Year
Stage # fish Survival Eggs 5000 0.6 Fry 3000 0.2 Parr 600 0.5 dam 1 300 0.9 dam 2 270 0.9 dam 3 243 0.9 dam 4 219 0.9 dam 5 197 0.9 dam 6 177 0.9 dam 7 159 0.9 dam 8 144 0.9 smolts 129 0.02 1 st year 2.6 0.7 2 nd year 1.8 0.8 3 rd year 1.4 0.9 4 th year 1.3 Hypothetical Snake River Spring Chinook Salmon Life table 300 to 129 salmon: 43% survival
Rates of travel and survival of Chinook salmon and steelhead smolts in the Fraser- Thompson and Columbia-Snake systems: Welch et al. 2008 506 km 349 km Columbia Fraser Km/day Chinook 21.6 53.7 steelhead 28.1 61.8 Survival (%) Chinook 47.7 22.6 steelhead 33.5 30.0 Note: Faster travel in the Fraser River, with no dams, but lower survival rates, despite shorter distances
Relationship between flow and water clarity at Ice Harbor Dam during chinook smolt seaward migration Secchi disk visibility (ft) 7 6 5 4 3 2 1 0 0 50 100 150 200 Bevan Team Recovery Plan. 1993. Daily mean flow (kcfs)
Preferred salinity of juvenile oceantype chinook based on distribution of fish in vertical salinity gradients Salinity (ppt) 30 25 20 15 10 5 0 25-Mar 14-Apr 4-May 24-May 13-Jun 3-Jul Whitman 1987
Babine Lake sockeye: Early smolts from North and Morrison arms, late smolts from the main lake.
Early and Late run sockeye from Babine Lake, B.C. 1967 Percent of the total run 12 10 8 6 4 2 Early run 9.73 Million Late run 6.83 Million 1 5 10 15 20 25 30 Days of the 1967 run
Relationship between water clarity and survival of chinook salmon passing Ice Harbor Dam Smolt to adult survival (%) 7 6 5 4 3 2 1 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 Secchi disk visibility (ft) Bevan Team Recovery Plan. 1993.
Yakima River Chinook Salmon Life table Stage # fish Survival Eggs 5000 0.05 Smolt 250 0.57 Prosser 142 0.7 McNary 100 0.9 John Day 90 0.9 Dalles 81 0.9 Bonneville 73 0.9 Adultsescapement 5.34 0.07 Fast et al. 1991. BPA Rept.
Characteristics of redds made by rainbow trout and steelhead on the Deschutes River, OR Form Depth (cm) Redd site Velocity (cm/s) Gravel (mm) Redd dimensions Length (m) Width (m) Steelhead 54.1 71.4 32.5 2.1 1.2 Rainbow 42.6 63.4 25.1 1.5 0.8 Zimmerman and Reeves 2000
Steelhead and rainbow spawning timing inferred from new redds in the Deschutes River, Oregon new redds (% of total) 25 20 15 10 5 0 Zimmerman and Reeves 2000 11 13 15 17 19 21 23 25 27 29 31 33 week of the year steelhead rainbow
Levels of ATPase activity in the gill tissue of wild steelhead caught migrating down the Snake River, migrating Dworshak Hatchery steelhead, and steelhead held at the hatchery Mean gill Na+ K+ ATPase activity 75 60 45 30 15 0 wild held released 10-Apr 20-Apr 30-Apr 10-May 20-May Sampling date Zaugg et al. 1985.
Plasma hormone concentration or body size Hormone levels in migrating Body size salmonids Critical period Insulin IGF-I Thyroxine Growth hormone Jan Feb Mar April May
Model of growth, survival, and reproductive potential of sockeye and kokanee Age form length survival number fecundity fitness 1st spring kokanee 28 0.1 50 sockeye 28 0.1 300 1st fall kokanee 60 0.4 20 3 0.12 sockeye 60 0.4 120 3 0.12 2nd spring kokanee 80 0.5 10 sockeye 80 0.5 60 2nd fall kokanee 120 0.8 8 24 0.38 sockeye 180 0.3 18 85 0.51 3rd fall kokanee 180 0.6 4.8 85 0.82 sockeye 360 0.4 7.2 700 1.68 4th fall kokanee 300 0.8 3.84 500 3.84 sockeye 560 0.8 5.76 3000 5.76
Atlantic salmon smolt age is inversely 6 related to growth opportunity Mean smolt age (years) 5 4 3 2 1 Thorpe 1994. TAFS 123: 606-612 0 10 20 30 Growth opportunity index 40 (temperature and day length)
Density-dependent growth and development of sockeye salmon Fry stocked into Leisure Lake, AK # Fry % age 1 Smolt Weight (g) Smolt stocked smolts age 1 age 2 biomass 0.5 M 97% 8.0 13.2 2009 1.0 77% 4.0 7.0 1894 1.5 87% 2.2 3.6 888 2.0 58% 1.8 3.4 771 Koenings and Burkett 1987
Millions of Fish Older and larger smolts tend to migrate earlier than smaller ones: Kvichak River sockeye 70 60 50 40 30 20 10 Percent Age II Numbers of Smolts 100 80 60 40 20 Percent 0 May June 0
Late and early Babine Lake salmon run counts from 1961-1983 Millions of Salmon 180 160 140 120 100 80 60 40 20 0 Late run Early run 1961 1965 1970 1975 1980 1983
Early and Late run sockeye into Babine Lake, B.C. 1979 Percent of the total run 22 20 18 16 14 12 10 8 6 4 2 Early run: 9.03 Million Late run: 99.19 Million 1 5 10 15 20 25 30 Days for the 1979 run