Biogenic carbonate budget in the North Pacific Ocean from sub-tropical to subpolar waters

Planktic calcifying organisms play a key role in regulating ocean carbonate chemistry, the food web, and as organic carbon ballasting mineral. Surprisingly, references to the absolute and relative contribution of these abundant calcifying organisms are rare and with large uncertainties We will present here results from a research cruise to document calcium carbonate production and dissolution in the North Pacific Ocean, conducted in August 2017 from Hawaii to Alaska, sailing from sub-tropical to sub-polar gyre waters. As part of this cruise, plankton tows were performed at the surface, in the photic zone and in the mixed layer at selected stations covering different latitudes from Aloha through PAPA stations. Our main goal was to characterize the carbonate contribution of the main planktonic calcifying organisms (coccolithophores, foraminifera, and pteropods) and environmental parameters controlling the production. Given that carbonate dissolution is a reaction that titrates ocean carbonic acid, the aragonite and calcite production by these abundant calcifiers can potentially have a role in the alkalinity budget of the ocean. This work aims to further our state of knowledge on the role of planktic calcifiers in the North Pacific carbonate production, and the implications related to their susceptibility to ocean acidification and warming.