Responses of two intertidal benthic copepod communities to seawater acidification

Ocean acidification is posing an ongoing threat to marine organisms and ecosystems. In this study the responses of two intertidal benthic copepod communities to seawater acidification were examined using microcosm experiment. Microcosms were incubated for 56 days in natural seawater (as control) and acidified seawater (pH 7.3, CO₂ concentration: 1900ppm) which simulating the predicted ocean acidification level in 2300 in a carbon dioxide climate incubator. In both types of sediment, total abundance of benthic copepods was significantly suppressed at pH 7.3 on 56d, however, the increasing of opportunistic species resulted in a less reduction of benthic copepod’s total abundance in coarser sediment. Community shift occurred on 56d for both sediment types. The community-based microcosm study indicated that seawater acidification could lead to changes of benthic copepod communities in intertidal sediments under extreme acidification scenario, but the communities inhibited in different sediments might response divergently.