Impact of ocean acidification on phytoplankton dynamics and bioelement cycling

Abstract

Ocean acidification (OA) is one of the many severe ongoing environmental changes resulting from the increase in anthropogenic CO₂. Many studies have reported that OA can affect marine organisms such as calcifying algae and animals. However, the interactive impacts of OA and other environmental stressors on marine phytoplankton remain poorly understood. First, we investigated the interactive effect of OA and iron availability on Bering Sea phytoplankton community. Second, we developed new culture media that allow for the independent manipulation of carbonate chemistry and iron availability. Third, we conducted unialgal culture experiments to examine the interactive effect of OA and iron availability using the new culture media. Through these above studies, we demonstrated that (i) iron availability could change as a result of OA in the iron-limited region of the Bering Sea, and (ii) CO₂ and iron availability can independently affect individual bioelements in different ways. This paper presents a brief summary of our previous studies, recent trends in OA research worldwide and the agendas of OA-related studies.