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Background: northern anchovy ( Engraulis mordax )

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Background: northern anchovy ( Engraulis mordax )

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  1. ARE the CONDITION AND growth of EARLY LIFE stages of northern anchovy related to the biochemical climatology of the Northern California Current?Jessica A. Miller1, William T. Peterson2, Louise Copeman3, Cheryl A. Morgan4,Marisa N. C. Litz11Oregon State University, Department of Fisheries & Wildlife, 2NOAA Fisheries, Northwest Fisheries Science Center, Newport, Oregon USA, 3Oregon State University, College of Earth, Ocean & Atmospheric Sciences, 4Cooperative Institute of Marine Resources Studies, Oregon State University

  2. Background: northern anchovy (Engraulismordax) northern subpopulation spawn mid-May to mid-September (12-15C) hatch at 2.5-3.0 mm TL rapid growth, short lifespan (<7 yr), early maturity (1 yr)

  3. Background: Climate variation and fisheries recruitment Early feeding & growth Critical Period Hypothesis (Hjort 1914) Stable Ocean Hypothesis (Lasker 1975; Peterman & Bradford 1987) No relationship between larvae and Age-1 recruits (Peterman et al. 1988) Relative adult abundance related to copepod community during ELH stages (Litz et al. 2008) Direct evidence that interannual variation in growth during ELH related to copepod community (Takahashi et al. 2012)

  4. Background: Variation in copepod community in Northern California Current Copepod Community Index (CCI) Variation in the copepod community composition and the biomass of northern species is well correlated with salmon survival (Peterson & Schwing 2003, Bi et al. 2011), marine growth of juvenile salmon (Tomaro et al. 2012), and the early growth of northern anchovy (Takahashi et al. 2012). WHY? The sign of the PDO is associated with relatively warm or cold water along the coast “warm” and “cold” water zooplankton communities in coastal waters are associated with positive or negative phases of the PDO, with a lag Warm-watercommunity Cold-water community Bill Peterson, NOAA. Morgan et al. 2003, Hooff & Peterson 2006, Keister et al. 2012

  5. Hypotheses Essential Fatty Acid / Prey Quality Hypothesis Changes in fish community lipid content are the result of climate-mediated changes in the availability of essential fatty acids (Litzow et al. 2006). Greater lipid content of the boreal copepods results in higher growth and survival of juvenile salmon and northern anchovy (Bill Peterson). The relative importance of prey abundance and quality not well understood.

  6. Hypotheses Objectives & Hypotheses Characterize seasonal & interannual variation in lipid classes and fatty acids in particulate organic matter, zooplankton, and early stages of northern anchovy Ho1: The lipid and fatty acid composition of the copepod community varies seasonally & interannually (greater lipid levels (wax esters) during spring/summer & in cooler years) Ho2: Growth rates of early stage northern anchovy are positively related to lipid levels and certain fatty acids in the copepod community

  7. Methods: copepod community composition • Biweekly collections • NH05, 60 m depth • 50-cm diameter, 202-m mesh ring net • “Copepod Patty” • 20-m mesh sample –POM/phytoplankton • Copepod Community Index (CCI) • Northern Copepod Biomass Anomaly • Southern Copepod Biomass Anomaly NH05

  8. Methods: early stages of northern anchovy (Engraulismordax) • 264-rope trawl with a small-mesh liner • Light traps • Condition (length-mass residuals) • Age, hatch date, growth rate Willapa Bay line Yaquina Bay

  9. Methods: lipid classes and fatty acid composition • OSU CIMRS Lipid Lab (Dr. Louise Copeman) • Phytoplankton, copepods, northern anchovy • Modified Folch procedure (extraction) • TLC-FID (lipid classes) • GC-FID (fatty acids)

  10. Methods: temporal coverage ---------Phytoplankton & Copepods--------- Northern anchovy Northern anchovy

  11. Results: Copepod Community Index • in total lipids after fall transition • in DHA/EPA after fall transition • Biochemical response precedes change in CCI DHA/EPA = docosahexaenoicacid/ eicosapentaenoicacid (~dinoflagellates/diatoms)

  12. Results: Growth & condition of early stages of northern anchovy • 96 individuals collected • 36.8 (±7.6 SD) mm SL • Mean age = 82 (±20) d (n = 73) • Age: 42-129 d May 14 ------------------------------------------------Aug. 12

  13. Results: Growth & condition of early stages of northern anchovy Cohorts based on hatch date May14-20, n = 15 Early June 3-18, n = 25 Late June (June 23-July 8), n = 16 July(July 18- Aug 2), n = 11 Capture date: Size & Condition July 21-22,n = 19 August 23, n = 28 October 7-8 ,n = 15 October 22-23, n = 18 Nov. 4, n = 3 Lipids n = 12 n = 14 n = 10 n = 10 n = 2

  14. Results: Northern anchovy condition at capture r = -0.797 Mean condition index (M-L residuals) Higher condition when boreal, lipid-rich species are dominant and have greater biomass r = 0.813

  15. Results: Growth of four cohorts of northern anchovy Mean otolith increment width (µm)

  16. Results: Temperature effects on growth

  17. Results: Temperature effects on growth Early otolith growth positively correlated with temperature r = 0.99

  18. Results: Growth & condition of early stages of northern anchovy potential growth observed growth 98.8% ± 9.2 SD

  19. Results: Growth & condition of early stages of northern anchovy potential growth observed growth northern anchovy residual growth - 10 d means centered around copepod sample northern anchovy residual growth =

  20. Results: Growth of early stages of northern anchovy & copepods Northern anchovy residual growth (mm/day) r = -0.68 Northern anchovy residual growth (mm/day) r = 0.59 r = -0.68

  21. Results: Growth of early stages of northern anchovy & copepod fatty acids Lipid storage Diatom indicator r = 0.875 Northern anchovy residual growth (mm/day) Carnivory? r = 0.834

  22. Summary & Future Directions • Clear seasonal variation in lipids classes and FA within the copepod community • Substantial intra-annual variation in anchovy growth – • related to temperature and copepod community composition • Intra-annual variation in early growth of northern anchovy related to • FA in copepod community (diatom indicators) • Those diatom indicators are better described by variation in the biomass of northern copepods than the Copepod Community Index (CCI) (r = 0.548 vs. r = 0.10) • Early growth of northern anchovy likely influenced by both the community and its relative abundance (individual size and density) • Analysis ongoing….second year of data collection nearing completion, • multivariate approaches, more detailed analysis of how changes in the copepod community relate to FA variation and anchovy growth

  23. Acknowledgements NOAA NWFSC & EPP Bonneville Power Administration Cheryl Morgan, OSU CIMRS Jay Peterson, NOAA NWFSC Jennifer Fisher, OSU CIMRS Tracy Shaw, OSU CIMRS Jesse Lamb XanaHermosillos, LMRCSC intern Nichelle Smith, LMRCSC intern Thomas Murphy, OSU

  24. Circulation off the Pacific Northwest Subarctic Current brings cold water and northern species to the N. California Current. The West Wind Drift brings subtropical water and subtropical species to the N. California Current. Ecosystem structure is affected by the source waters which feed the California Current.

  25. Cool Phase  Transport of boreal coastal copepods into NCC from Gulf of Alaska Warm Phase  Transport of sub-tropical copepods into NCC from Transition Zone offshore “Cool” Phase “Warm” Phase Keisteret al. 2011; Bi et al. 2011

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