Course: 2 Plankton community

Study on Plankton Community from Surface to Deep Sea in the Western North Pacific

～ Characteristics of Depth Distribution by Classification Group, Differences between Subarctic and Subtropical Zones ～

Collection points
Collections were performed at four stationary points located in the subarctic to subtropical regions.
Plankton collection instrument page

The biomass of all taxa decreased with increasing water depth. The degree of decrease was greater for heterotrophic bacteria < unicellular animals < plants < multicellular animals.

バイオマス：Biomass
従属栄養性細菌：Heterotrophic bacteria
単細胞生物：Unicellular organisms
動物：Animals
多細胞生物：Multicellular organisms
［[Question] Why does the degree of reduction change for each group of organisms? Page
[Question] Why does the biomass of multicellular animals continue to decrease in depth? Page
[Question] Why does it even exist in deep (dark)? Page

Multicellular animals predominate in the subarctic zone (A-C) and heterotrophic bacteria and unicellular animals predominate in the subtropical zone (D-F).
各分類群の割合（％）：Percentage (%) of each taxonomic group
水深（ｍ）：Depth (m)
全プランクトンバイオマス（mgCm-3）:Total plankton biomass (mgCm-3)
バイオマス：Biomass
従属栄養性細菌：Heterotrophic bacteria
単細胞生物：Unicellular organisms
動物：Animals
多細胞生物：Multicellular organisms
[Open Access] Yamaguchi et al., 2004, Journal of Oceanography URL
[Question] Why do heterotrophic bacteria and unicellular animals prefer in the subtropical region? Page
[Question] What is the reason for the small proportion of plants? Page

Biomass was determined in all planktonic communities (plant-multicellular animals) ranging from surface to deep water (5800 m) at four stationary points located in the subarctic to subtropical regions of the North Pacific.

All plankton taxa showed a decrease in biomass with increasing depth, but the degree of decrease varied by taxon, in the order of heterotrophic bacteria < unicellular animals < plants < multicellular animals.

3 copepods URL

This section introduces the representative zooplankton, caecilians.

2 Plankton community