Changes in survival rates by stages of harpacticoid copepods, Tigriopus japonicus with increases in dissolved CO2 in seawater

Abstract

Recently, many studies are carried out on the effect of increased dissolved carbon dioxide in seawater and reduced seawater pH (ocean acidification) that corresponds to the increasing atmospheric CO2. For our studies, as part of growing need to ascertain the effects of ocean acidification on marine ecosystem and organisms, harpacticoid copepods, one of the most abundant meiofaunal groups were subjected to laboratory experiments. The purpose of this study was to evaluate physiological and ecological responses of harpacticoid copepods to the various concentrations of dissolved CO2 which might be observed in the future. First, we selected Tigriopus japonicus, one of harpacticoid species, which were easily collected in abundance and also easily subjected to incubation as an experimental organism. To examine the changes in survival rates of adult and Nauplius stages of Tigriopus japonicus with different dissolved CO2 concentrations (400, 1000, 1550 ppm) in seawater, we performed experiments using the CO2-addition experimental system for 14 days. In experiments, groups exposed to 1550 ppm compared with other concentrations showed the lowest survival rates as time passes. Nauplius stage showed a bigger drop than adult stage for 7 days.d to ascertain the effects of ocean acidification on marine ecosystem and organisms, harpacticoid copepods, one of the most abundant meiofaunal groups were subjected to laboratory experiments. The purpose of this study was to evaluate physiological and ecological responses of harpacticoid copepods to the various concentrations of dissolved CO2 which might be observed in the future. First, we selected Tigriopus japonicus, one of harpacticoid species, which were easily collected in abundance and also easily subjected to incubation as an experimental organism. To examine the changes in survival rates of adult and Nauplius stages of Tigriopus japonicus with different dissolved CO2 concentrations (400, 1000, 1550 ppm) in seawater, we performed experiments using the CO2-addition experimental system for 14 days. In experiments, groups exposed to 1550 ppm compared with other concentrations showed the lowest survival rates as time passes. Nauplius stage showed a bigger drop than adult stage for 7 days.