Monitoring for precocious male maturation (minijacks) in hatchery programs: A case study of upper Columbia River summer Chinook salmon

Transcription

1 Monitoring for precocious male maturation (minijacks) in hatchery programs: A case study of upper Columbia River summer Chinook salmon Don Larsen, Brian Beckman, Paul Parkins, Kathy Cooper, Deb Harstad, and Dina Spangenberg NOAA Fisheries, Northwest Fisheries Science Center Seattle, Washington

2 Spawning - Fall Chinook Salmon Fry Parr Age-1 Precocious parr Jack Age-2 Minijacks Age-5 Age-3 M Age-4 Sub-adults Ocean 1+ yr Spring Smolting

3 Variation in Age of Male Maturity Factors Affecting Age of Maturation Genetics Environment temperature food availability food quality Growth & Body energy stores Mature male salmon The Hatchery environment can significantly influence age of maturation

4 We ve been monitoring the physiology of Cle Elum Supplementation Hatchery Spring Chinook since implementation in 1997

5 On average 50% of male Cle Elum hatchery spring Chinook precociously matured at age-2 BY Release # % of males # Minijacks ,048 44% 84, ,683 72% 211, ,789 50% 189, ,285 37% 153, ,236 52% 95,520 Avg. 50% Larsen, D.A., Beckman, B.R., Cooper, K.A., Barrett, D., Johnston, M., Swanson, P., and Dickhoff, W.W. (2004). Assessment of high rates of precocious male maturation in a spring Chinook salmon supplementation hatchery program. Transactions of the American Fisheries Society. 133,

6 How do we assess precocious male maturation?

7 Age-2 immature male chinook salmon Testes May

8 Age-2 precocious male chinook salmon Testes May

9 Plasma 11-ketotestosterone (11-KT) O OH O Major androgen in teleost fish Instrumental in the regulation of spermatogenesis

10 Laboratory based studies have clearly established that 11-ketotestosterone (11-KT) is significantly elevated in precocious males as much as a year prior to mating * * * * *** * *** * *** * Precocious male Immature male 5 0 Dec Jan Feb Apr May Jun Sep (Campbell et al. 2004)

11 Every March the Cle Elum Chinook are screened for pathology just prior to volitional release Plasma collection 52% 48% Count Immature Threshold (0.8 ng/ml) Maturing Log KT (ng/ml) N = 541

12 Consequences of high levels of precocious maturation Ecological impacts Genetic impacts Increased straying Skewed gender ratio Loss of adult production Alter accuracy of SAR s

13 Entiat Hatchery Winthrop Hatchery Methow Entiat Count Winthrop BY 03 23% BY 04 28% BY 05 35% BY 06 39% Leavenworth Hatchery Wenatchee Log 11-KT 50 Cle Elum BY 01 48% Cle Elum Hatchery Count Entiat BY 03 13% BY 04 8% BY 05 11% Count Count Log KT (ng/ml) 10 Leavenworth BY 03 15% BY 04 14% BY 05 33% BY 06 25% Log 11-KT Log 11-KT Imnaha BY 06 51% Lostine BY 06 47%

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15 Minijacks are ubiquitous throughout the Columbia Basin Adult return ladders are fitted with pit-tag detectors Beckman, B.R. and Larsen D.A. (2005). Up-stream migration of PIT-tagged Age 2 (minijack) Chinook salmon in the Columbia River: behavior, abundan ce, distribution, and origin. Transactions of the American Fisheries Society. 134,

16 Minijacks were detected at Bonneville Dam from all releases # PIT-tags detected Carson Umatilla Clark Flat Jack Creek Easton Leavenworth Entiat Winthrop Methow Chewuch Dworshak Lostine Catherine Creek Imnaha Rapid River Knox Bridge

17 Mid/Upper Columbia Summer Chinook Salmon

18 Similkameen Pond Similkameen Carlton Pond Methow Dryden Pond Wenatchee

19 Methods April, 2008 collect random net grab samples of 300 fish from Carlton (Methow), Dryden (Wenatchee), and Similkameen Ponds prior to release. Measure fork length and weight, visually determined gender Collect blood and determine plasma 11-KT levels in all males via ELISA at NW Fish. Sci. Ctr., Seattle. Age-2 minijacks determined by 11-KT levels in excess of 1.5 ng/ml.

20 Mid-Columbia Summer Chinook - size comparison Weight (g) Fish per pound Carlton Pond Dryden Pond Similkameen Pond Length (mm) Carlton Pond Dryden Pond Similkameen Pond

21 11-KT frequency distribution between stocks Carlton Pond Count % of males Minijacks 74, 000 fish (400,000 released) Dryden Pond Count % of males Minijacks 73,440 fish (864,000 released) Similkameen Pond Count Log 11-KT 10% of males Minijacks 28, 800 fish (576,000 released)

22 11-KT levels in males and minijacks Ketotestosterone (ng/ml) Male Minijack 0-2 Carlton Pond Dryden Pond Similkameen Pond

23 Minijacks are generally the largest fish Length,mm Female Male Minijack Carlton Pond Dryden Pond Similkameen Pond

24 Minijack rates may influence SAR s (avg. % over years).9.8 Similkameen.7 SAR (%) Dryden Carlton.3.2 R 2 = Minijacks (% males) Columbia Basin Research School of Aquatic and Fishery Science University of Washington Web@cbr.washington.edu

25 Conclusions Minijacks are ubiquitous among all spring Chinook populations we ve surveyed. Supplementation programs using localized broodstocks may have increased susceptible to this life-history. Minijack rates among hatchery Summer Chinook populations are relatively variable (high and low). The economic, ecological, and genetic impacts of this phenomenon may be significant Smolt quality monitoring is a useful tool for helping make informed decisions about hatchery uses and practices.

26 Acknowledgments Cle Elum Hatchery- Charles Strom and staff WDFW-Todd Pearsons and staff, Steve Schroder, Craig Busack Yakama Nation Fisheries-Dave Fast, Mark Johnston, Bill Bosch Leavenworth Hatchery Complex Facilities-Steve Croci, Dan Davies, Al Jensen, Chris Pasley, Craig Eaton, Jason Reeves Nez Perce Tribe - Peter Cleary, Jim Harbeck ODFW- Tim Hofnagle, Diane Deal and staff (Lookingglass Hatchery), Sam Onjukka and staff (ODFW fish health) WDFW Upper Columbia - John Penny and staff (Dryden), Guy Wiest, Dave Dinsmore (Carlton), Tim Holder, Carol Coleman(Similkameen) Chelan and Grant County PUD s - Chuck Peven and Russ Langshaw USFWS Pathology Lab, Olympia, WA.- Ray Brunson, Joy Evered, Sonia Mumford, Chris Paterson Bonneville Power Administration - Deborah Docherty, NOAA Biop Funding