Oysters provide critical ecosystem services including providing habitat, locally buffering against corrosive conditions, and serving as a harvestable resource. In addition, coastal economies including the livelihoods of hatchery personnel and oyster growers depend on healthy oyster populations.
Rising atmospheric carbon dioxide levels have resulted in acidification of the Earth’s oceans. With CO2 levels expected to continue to rise, great concern exists over the impact ocean acidification will have on marine ecosystems. In coastal regions such as the Pacific Northwest upwelling may contribute to regional ocean acidification by bringing low pH water to the surface. This low pH water is corrosive to calcium carbonate shells such as those formed by bivalves (like oysters), crustaceans and corals.
Water chemistry sensors are extremely expensive to implement, meaning that only a select few estuaries have pH and carbonate system chemistry resolved. Using our pH proxy will allow us to understand the variability of carbonate within Netarts Bay. The successful development of this proxy will allow us to use oyster shells as a means of resolving water chemistry in areas where water chemistry instruments are cost prohibitive.
Dissolution of these dead oyster shells act as the Alka-Seltzer of the sea, buffering the local water around the living oysters situated on top of the shell plantings. Shell planting is a potential tool for buffering against increasingly acidic oceans as well as local acidity associated with remineralization of organic matter and the associated production of carbon dioxide at the sediment-water interface.
Next week: how do we take these concepts and apply it in research?