Effects of CO2 Ocean Sequestration on Deep-Sea Animals

This paper describes our recent experimental results to elucidate the effects of high CO₂ on a deep-sea fish. A few species can be captured alive from depths of ca. 400 meters and be used for in vivo CO₂ exposure experiments. We have developed an experimental setup that allows us to expose deep-sea organisms to high pressures (up to 20 kPa) at low temperatures (1-2 degC) for extended periods. This setup also allows us to monitor physiological state of exposed animals through electrocardiogram for cardiac activities and electromyogram for respiratory movements. We will discuss the latest results on the effects of CO₂ on a deep-sea fish Careproctus trachysoma (Liparididae) under pressures of 6-10 kPa at 2 degC. Preliminary results indicate that the fish would die earlier under high pressures than when they are exposed to the same C02 conditions (20,000 muatm) at atmospheric pressure. Electrocardiogram has been successfully recorded from the fish, demonstrating that heart rate rapidly declined when they were exposed to 20,000 muatm CO₂ under high pressure.