Paul McElhany, NOAA Northwest Fisheries Science Center
Ecosystem models are used to estimate the potential direct and indirect effects of ocean acidification (OA) on marine resources. The population abundance and distribution of species that are sensitive to seawater carbonate chemistry can experience the direct effects of OA. Even species not sensitive to carbonate chemistry can have indirectly changes in abundance and distribution as a result of changes in their prey, predators, competitors or critical habitat forming organisms that are sensitive. Ecosystem models use information on food webs and other relationships to estimate these ripple effects of OA on important ecosystem services like fisheries.