Saeko Mito

Detrmination of mesopelagic food web structure for ecological impact assessment of carbon dioxide ocean sequestration

Publisher Summary This chapter aims at determining the food web structure of deep-sea by stable isotope ratios of organisms to provide base information necessary for monitoring the ecosystem alterations induced by the CO2 ocean sequestration. Stable isotope ratios of carbon and nitrogen are useful in determining the food web structure. Through metabolism of organisms, the heavier isotope is accumulated in their body while the lighter isotope is excreted to the ambient. Isotope ratios in the organisms become heavier with the increase in the trophic level because of their feeding habits over long term. It was suggested that the structure of mesopelagic food web might be simple because of the limited food source. Intentional injection of CO2 into deep-sea will result in alteration of the trophic position of each organism. It was expected that such an ecosystem alteration could be monitored by means of stable isotope ratios of the organism.