Swimming inhibition by elevated pCO₂ in ephyrae of the scyphozoan jellyfish, Aurelia

抄録

Ephyrae of the scyphozoan jellyfish, Aurelia, were exposed to hypercapnic seawater (pCO₂ 5,000 to 50,000 μatm) for 96 h, to study the impacts of potential CO₂ seepage from a geological storage site beneath the ocean floor. Geological CO₂ storage has been proposed as a mitigation measure against global warming but ecological consequences in the case of seepage are largely unknown. No mortality occurred within the pCO₂ range used in the present study. Swimming arm pulsation was significantly depressed in animals exposed to 5,000 μatm pCO₂ compared to control animals, and immediately ceased in animals exposed to ≥30,000 μatm. When returned to normocapnic seawater (pCO₂ 380 μatm) after 96 h exposure to 50,000 μatm pCO₂, some ephyrae showed strong arm inversion. These results indicate that even though Aurelia is able to survive short-term exposure to pCO₂ of up to 50,000 μatm, the strong inhibition of swimming activities under these conditions would reduce the environmental fitness of affected animals.