Effects of high CO2 seawater on the copepod (Acartia tsuensis) through all life stages and subsequent generations

We studied the effects of exposure to seawater equilibrated with CO2-enriched air (CO2 2380 ppm) from eggs to maturity and over two subsequent generations on the copepod Acartia tsuensis. Compared to the control (CO2 380 ppm), high CO2 exposure through all life stages of the 1st generation copepods did not significantly affect survival, body size or developmental speed. Egg production and hatching rates were also not significantly different between the initial generation of females exposed to high CO2 and the 1st and 2nd generation females developed from eggs to maturity in high CO2. Thus, the copepods appear more tolerant to increased CO2 than other marine organisms previously investigated for CO2 tolerance (i.e., sea urchins and bivalves). However, the crucial importance of copepods in marine ecosystems requires thorough evaluation of the overall impacts of marine environmental changes predicted to occur with increased CO2 concentrations, i.e., increased temperature, enhanced UV irradiation, and changes in the community structure and nutritional value of phytoplankton.