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Estimating dispersal and population size of amphidromous gobies

James F Gilliam North Carolina State University. Michael J Blum Tulane University. Peter B McIntyre University of Wisconsin. Estimating dispersal and population size of amphidromous gobies . Objectives. Improve understanding of oceanic island stream ecosystems

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Estimating dispersal and population size of amphidromous gobies

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  1. James F Gilliam North Carolina State University Michael J Blum Tulane University Peter B McIntyre University of Wisconsin Estimating dispersal and population size of amphidromous gobies

  2. Objectives Improve understanding of oceanic island stream ecosystems Assess responses of at-risk native fishes to environmental stressors

  3. Objectives Assess responses of at-risk native fishes to environmental stressors …information on dispersal and population size can guide best management practices

  4. Lentipes concolor Awaous guamensis Eleotris sandwicensis Amphidromous life history Sicyopterus stimpsoni Stenogobius hawaiiensis Study system All native stream fishes exhibit an amphidromous life history

  5. Study system

  6. Study system: Potential bottlenecks

  7. Approaches Carry out studies of genetic variation, dispersal & population size Assess covariance with watershed land use and in-stream conditions Develop quantitative models of dispersal and population dynamics

  8. Genetic structure Source tracking Pop size & immigration Genetic diversity Genetic approaches Genetic assays provide information on individual and population responses to environmental stressors and account for dispersal

  9. Quantitative modeling Comparative approaches DNA sequencing DNA genotyping Otolith microchemistry Population census Assemblage structure In-stream habitat Watershed land use Validation of genetic assays with independent measures of movement and population size

  10. Ocean-stream connectivity Are there island specific evolutionary lineages? Analysis of mitochondrial DNA haplotype variation among islands in Awaous guamensis

  11. Ocean stream connectivity Directional isolation-by-distance pattern of haplotype variation among islands in A. guamensis

  12. Ocean stream connectivity Distinct evolutionary lineage of Awaous in Hawaii (2-3 myo)

  13. Geographic patterns of dispersal Does local recruitment draw from mixed immigrant pools due to larval exchange? Genetic comparisons of recruiting postlarvae and resident adults >15% <15% >15% <15% <5% <5% Waimea River watershed, Kauai Waihee Stream watershed, Maui

  14. 4 Hawaii 1 FACTOR 2 Kauai -2 Molokai -5 -5 -2 1 4 FACTOR 1 Geographic patterns of dispersal Does local recruitment draw from mixed immigrant pools due to larval exchange? Awaous otolith microchemistry can distinguish islands and watersheds

  15. Responses to environmental stressors Does genetic diversity reflect in-stream conditions & watershed land use? Genetic diversity of Awaous guamensis declines as in-stream conditions decline

  16. Responses to environmental stressors Does population densities reflect in-stream conditions & watershed land use?

  17. Expanding genetic datasets to better define dispersal & responses to environmental stressors within watersheds Expanding otolith microchemistry datasets to improve technical approaches, and to better define dispersal and age-size relationships Completing mark-recapture studies of population size, recruitment and survival within watersheds Ongoing studies

  18. Completing mark-recapture studies of population size, recruitment and survival within watersheds Ongoing studies

  19. Methods development Genetic methods are informative for tracking dispersal among populations Otolith microchemistry is a promising tool for tracking dispersal among populations Genetic methods are informative for assessing responses to watershed land use and in-stream conditions

  20. Outcomes Improved understanding of ocean-stream interhabitat connectivity Valuable information for land stewardship across Hawaii New and powerful tools for environ-mental assessment, watershed management & stream restoration

  21. Acknowledgements Dr. Brad Lamphere (NCSU) Dr. Daniel Lindstrom (U of Guam) Dr. Ryan Walter (NCSU / Tulane) Dr. Derek Hogan (Tulane / Wisconsin) Dr. Nate Bickford (U. Great Falls) Dr. Tom Rayner (UNSW) Ernie Hain (NCSU) Erick Gagne (Tulane) Greg Glotzbecker (Tulane) Travis Haas (Tulane) Brandon Policky (Tulane) Jacqueline Fenner (Michigan State) Kristine Moody (Clemson) Takahashi Maie (Clemson) US Dept of Defense US EPA HI Division of Aquatic Resources

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