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Arctic Cisco Genetics and Otolith Microchemistry

Arctic Cisco Genetics and Otolith Microchemistry. Jennifer L. Nielsen Christian E. Zimmerman Vanessa Von Biela USGS Alaska Science Center. Alaska Marine Science Symposium Anchorage, Alaska January 22, 2009. Generalized Arctic Cisco Life History. Nuiqsut Subsistence Fishery.

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Arctic Cisco Genetics and Otolith Microchemistry

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  1. Arctic Cisco Genetics and Otolith Microchemistry Jennifer L. Nielsen Christian E. Zimmerman Vanessa Von Biela USGS Alaska Science Center Alaska Marine Science Symposium Anchorage, Alaska January 22, 2009

  2. Generalized Arctic Cisco Life History

  3. Nuiqsut Subsistence Fishery • Recent declines in abundance and size of Arctic cisco – population-of-origin effects? • Impacts of climate on sustainable harvest – effects of changes in Arctic oscillation and/or changes in prey abundance? Under-ice gillnet subsistence harvest

  4. Migration and Growth in Arctic Cisco Testing the “Mackenzie Hypothesis” Colville River, AK subsistence harvest 2005-2007 Beaufort Sea Mackenzie River, CA 5 anadromous spawning locations 2007-2008 Gulf of Alaska

  5. Otoliths depict migration history and act as natural growth records Sr/Ca Ratios Otolith radius and fish length were proportional

  6. Using Otolith Micro-chemical Analyses to Understand Fish Populations

  7. Otolith growth vs. fish length 1986-2007 (no samples 1989, 2002-2004) (r2 = 0.84; P < 0.0001)

  8. Young-of-the-Year Otolith Growth 1989 Pacific Ocean climate shift (Hare & Mantua 2000) 1997 Pacific Ocean climate shift ANOVA: n = 819; p < 0.0001

  9. Winter Arctic Oscillation Index p=0.0262

  10. Young-of-Year Growth Correlations Environmental Factors Air Temperature (Inuvik May-August) Easterly Wind Speed (Barrow July- August) r2 = 0.15 r2 = 0.16 No correlation found between YOY growth and proportion of easterly winds

  11. Mackenzie River Dischargem3/s, April-June P = 0.0001

  12. Young-of-the-Year Growth • Most environmental factors accounted for only small proportion of variation in YOY growth • 2-yr lagged river discharge accounted for half the variability in YOY growth • YOY growth may increase after high discharge years when increased nutrient input stimulates lower trophic production

  13. 2-year Lag Growth Hypothesis Increased spring river discharge, DOC, and nutrients(Carmack et al. 2004, Dunton et al. 2006, Holmes et al. 2008) Increased 1° production in the Mackenzie plume(Carmack et al. 2004, Garneau et al. 2006, Pedersen et al. 2008) Also consider transport of plankton Across shelf and between N. Pacific and W. Arctic Oceans Carin Ashjian et al. 2005 & 2008 Higher zooplankton abundance in the next generation (2nd year) (Schell et al. 1998, Dunton et al. 2004)

  14. Genetic Data Population-of-Origin Analyses • 11 microsatellite loci genotyped for Arctic cisco (28 loci screened and 4 new loci maximized) • mtDNA ATPase6 gene sequenced (594 nt) Microsatellite alleles mtDNA nucleotide sequence

  15. Genetic Analyses 2005-2007 N = 54 (Peel) N = 60 (Arctic Red) N = 86 (2005) N = 176 (2006)

  16. 11 Microsatellite Loci • Average: NA = 25.5; AR = 15.1; HO = 0.775; HE = 0.774 • All microsatellite loci were in HWE & linkage equilibrium • Global FIS = 0.000 (p = 0.49) for all loci combined • No significant pairwise FST differences between collections by year or location (p ≥ 0.21 in all cases) • No significant differences between Alaskan and Canadian Arctic cisco (pairwise FST = 0.0007, p = 0.11) • No significant allelic frequency differences among age classes in the 2006 Colville River subsistence fishery (p ≥ 0.09 in all cases) • STRUCTURE inferred one genetic cluster (K = 1)

  17. mtDNA Results • Characterized 19 unique Arctic cisco ATPase6 haplotypes • No significant pairwise FST differences among haplotype frequencies by year or location • 4 highly divergent haplotypes present in the Colville River • 3 haplotypes aligned with Bering cisco mtDNA • 1 unknown haplotype (putative Coregonus spp.)

  18. mtDNA Minimum Spanning Network • Sample sizes • 372 Arctic cisco • 8 Bering cisco • 1 unknown Coregonus

  19. Conclusions: YOY Growth • Variation in YOY Arctic cisco growth could be described by: Mackenzie River discharge, air temperature, and easterly wind speed • Best-fit model included variables: • 1) Mackenzie discharge lagged 2 years • 2) Inuvik summer air temperature • Model explains ~60% of variability in YOY growth 1986-2007

  20. Conclusions: Genetics • Arctic cisco sampled in the Mackenzie River show high levels of gene flow among putative spawning populations in the Arctic Red and Peel rivers (panmixia?) • Arctic cisco from the Colville and Mackenzie rivers lack independent genetic structure. • Results from this study support the “Mackenzie Hypothesis” with one population of origin for fish caught in the Colville River subsistence fishery. • Rare coregonid haplotypes found in Colville River fishery require additional study to determine origins and possible hybridization among North Slope whitefish.

  21. Acknowledgements Kate Wedemeyer (Minerals Management Service); Paulo Flieg and Larry Greenland (Aurora Research Institute); Shawn Norbert (Tsiigehtchic resident); Gwich’in Renewable Resource Board (Inuvik); Tetlit Renewable Resource Council (Fort McPherson); Gwichya Renewable Resource Council (Tsiigehtchic) ; Sean Burril; Andy Ramey; Sara Graziano; Larry Moulton; John Seigle, ABR; ConocoPhillips (Anchorage) ; LGL Limited (Anchorage); US Fish & Wildlife Service (Anchorage).

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