Seasonal dynamics of planktonic food chain in the Oyashio region, western subarctic Pacific

Abstract

In order to clarify the importance of the microbial food chain in relation to the grazing food chain in the Oyashio region, western subarctic Pacific, the biomass of component organisms in the two food chains was investigated during July and October in 1997, and January, March and May in 1998. Carbon flows within the plankton food chains, as established from biomass data combined with published experimental data (Shinada et al., 2000), suggest that primary production is largely channelled through the microbial food chain throughout the year. The grazing food chain is functional along with the microbial food chain only during the spring phytoplankton bloom.