Acidification Stress - Commercially Important Bivalves
Developing realistic metrics of acidification stress for commercially important bivalves in variable habitats P.I. George Waldbusser Co P.I.s Burke Hales, Chris Langdon Students Rebecca Mabardy, Iria Giménez Oregon Sea Grant- All Hands Meeting 9 March 2012
What’s the Big Idea? Coastal ecosystems are variable, organisms that live in these environments must compensate basic physiology to deal with environmental stress. When environmental stress exceeds capacity for acclimation, then organism fitness suffers. To date, almost all acidification studies have focused on responses in static conditions, however organisms in coastal and estuarine environments live in a fluctuating world. We therefore need tools to understand environmental stress impacts in a realistic, variable, messy world. Our model system is Pacific Oyster Larvae in Oregon Coastal Waters Our approach is to use a Degree Day Type Model that accounts for different Components of Carbonate Chemistry Variability in coastal waters. Goal- To develop a model that will help oyster growers and hatcheries to determine success of oyster “crops” under a highly variable system.
~ size egg reserves are depleted Size at 24 hrs Free swimming larvae 6-12 hrs>22oC Fertilized egg Larvae ready to ‘settle’ 14-21 days Pacific Oyster Gametes Life Cycle Reproductive adults 2-3 Years Oyster spat 1-2 months
Conditions in Netarts Bay(May to August 2009) Conditions during early shell development critical to overall cohort production. Barton et al. (in press)
Diurnal Variability in Netarts Bay (July 8-17, 2009) Even over that critical initial 24 hour window, conditions are highly variable. Therefore, environmental stress may be related to different components of the system variability. Barton et al. (in press)
Degree Day Models 17 different stocks of North Atlantic Cod (Neuheimer and Taggart 2007) Accumulated thermal effect on growth. Why not accumulated acidification stress on growth and survival?
Experimental Challenges How to vary conditions? Working with NWFSC-NOAA Seattle to utilize their experimental system How to measure stress? Overall growth and survival (~weeks) RNA:DNA on short time scales (<hours) How to account for different life stages? Model will have variable stress parameters over life historyNWFSC-NOAA Montlake Facility RNA:DNA Life History Ecology
Rebecca MabardyOutreach Plan MRM Master’s StudentOregon Oyster Hatcheries Integrated Ecosystem Study & Public Engagement ModelExpand Stakeholder Engagement Hatchery operators and oyster growers Gauge stakeholder perception of Ocean AcidificationWeb based model output of “Acidification Climatology” Akin to other meteorological data Heating Degree Days Rainfall Total Acid Stress Hours (ASH) Model has potential applications to other organismsOcean Acidification Lesson Plan and Activities (High School Level or Science Center)Website to provide user friendly interface and translation of science to public. To inform about Oregon’s coastal dynamics and oyster physiology/ecology “Why should we care about ocean acidification in highly variable system?” “Oysters have grown for years in this system, what changed?” “What is unique about bivalves in how they grow and maintain shells?”
Where we are… Awaiting Index Number… • Literature Review of bivalve larvae stress responses • Outreach components begun • Method development for RNA:DNA • Larval Stress experiments this summer with NOAA-NWFSC • Conceptual paper on PID approach to stress in variable environments Acknowledgements: Paul McElhaney Shallin Busch