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Add To Calendar 24/02/2016 09:15:0024/02/2016 09:35:00America/ChicagoAquaculture 2016ACCLIMATE OR ADAPT: A TWO-PRONGED APPROACH TO IMPROVE RESILIENCE TO OCEAN ACIDIFICATION IN THE PACIFIC OYSTER BurgundyThe World Aquaculture Societyjohnc@was.orgfalseanrl65yqlzh3g1q0dme13067DD/MM/YYYY


Daniel Gillon*, Molly Jackson, Benoit Eudeline, Brett Dumbauld, Dacey Mercer, Steven Roberts, Jonathan Davis, & Carolyn S. Friedman
School of Aquatic & Fishery Sciences, University of Washington, Seattle WA 98105

Repeated losses of Pacific oyster (Crassostrea gigas) larvae and juveniles in Northeast Pacific shellfish hatcheries over the past decade have been linked to ocean acidification (OA). Successful hatchery production of oyster larvae has relied on artificially buffering incoming seawater with sodium carbonate (Na2CO3) or physically transporting pediveliger larvae to "remote setting" sites with higher seawater saturation state of aragonite (ΩA). Despite buffering, loses of Pacific oyster larvae and juveniles continue at some sites. Variability in utility of buffering and projected increases in the severity and duration of OA events highlight a critical need for more proactive tools. We proposed a two-pronged experimental method to address this need: 1) Crossbreeding for resilience to OA in hybrid C. gigas lines; and 2) Assessing the potential for transgenerational acclimation and family selection under OA conditions. In a first experiment, multiple pedigreed, inbred parental lines of C. gigas were mated in a full-factorial design. Hybrid offspring were then screened for survivorship and growth during embryogenesis and again during settlement/metamorphosis under high and low ΩA. Crossbreeding of inbred C. gigas broodstock has been shown to dramatically improve yield in hybrid offspring through growth heterosis (Hedgecock & Davis 2007). We hypothesized that this approach could achieve high yield in specific hybrid crosses or their reciprocals under OA conditions. In a second experiment, we investigated the potential for transgenerational acclimation to OA following broodstock exposure to high carbon dioxide (pCO2; low ΩA) during reproductive conditioning. Preliminary data suggest that exposing G0 broodstock to high pCO2/low ΩA during gametogenesis may enhance G1 larval growth and survival, as well as improve post-settlement yield. We are further exploring whether this pattern persists in G2 larvae and seed. We employ microsatellite genotyping to assess differential success of specific families and to inform our breeding design. When taken together, both of these strategies may enhance the resilience of hatchery-cultured bivalves to an acidifying ocean.

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