ABSTRACT

KEVIN J. FLYNN, DARREN R. CLARK, ADITEE MITRA, HEINER FABIAN, PER J. HANSEN, PATRICIA M. GLIBERT, GLEN L. WHEELER, DIANE K. STOECKER, JERRY C. BLACKFORD, and COLIN BROWNLEE

9.1 INTRODUCTION

Effects of ocean acidification (OA), and specifically the impacts of higher pCO2 and a lower pH (higher [H

+]) on marine life are subjects of much research. Taken together with other climate change events, notably changes in temperature and water-column stability, OA has the potential for various impacts upon marine plankton communities and production [1-9]. The removal of CO2 by primary production leads to seawater basification (increase in pH), and the tendency towards this event is enhanced by increased nutrient availability. Indeed, in coastal waters subjected to

eutrophication by addition of inorganic nutrients that support large algal blooms, the increase in pH can be highly significant and can override any signal from OA [10]. On the contrary, when organic eutrophication promotes increased system respiration (net addition of CO2), then acidification is increased [11]. Events can also run in series, with inorganic eutrophication promoting first primary production and then respiration during decay of the bloom biomass. Either way, the system pH displays variations that may affect ecology, and these events will be affected with OA by commencement at a lower pH. Such transients are of most consequence in the highly dynamic coastal zones which contain elevated nutrient loadings in comparison with the relatively stable and low nutrient oligotrophic oceans.