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Terrie Klinger, University of Washington Larval rockfish dispersal trajectories in the Georgia Basin/Puget Sound Region of Washington state We propose to use trace element analysis of otoliths from adult and larval rockfish in the Georgia Basin/Puget Sound region to determine the sources from which larvae originate and the oceanographic regions they occupy during the larval dispersal phase. The elemental composition of fish otoliths has been used successfully to identify stock structure, recruitment patterns, and dispersal pathways for a number of fish species from tropical and temperate regions. The technique has great potential for use in the Georgia Basin/Puget Sound region because of the strong riverine and oceanic signals provided by inputs from the Fraser River and Strait of Juan de Fuca, respectively. We propose to use two species of rockfish as model systems. Copper rockfish (Sebaster caurinus) and quillback rockfish (S. maliger) are species of local importance. Both have shown sharp declines in abundance over the last few decades, and both are now important regional conservation targets. The research we propose is highly relevant to problems of bottomfish recovery, marine conservation, and marine protected area design. The results of our research will indicate whether populations of these rockfish species constitute open populations characterized by substantial long-distance larval dispersal, or whether these are closed populations in which larval dispersal is spatially limited. Our results will help guide the design and implementation of marine protected area networks in the Georgia Basin/Puget Sound region and throughout Washington state. |