Studies on long-term variation of ocean ecosystem/climate interactions based on the Odate collection: outline of the Odate Project

• Main Author: Hiroya Sugisaki
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.541.8524; http://www.pices.int/publications/pices_press/Volume14/v14_n1/pp_12_15_Odate collection.pdf

Recently, long-term variations and trends of global climate have been identified as serious problems affecting the biosphere, especially global warming problem. The ocean is thought to play an important role by absorbing carbon dioxide (the most serious greenhouse gas) through various biological processes. Phytoplankton synthesize carbon dioxide in the surface layer and are mainly consumed by zooplankton. The subsequent destination of the carbon, however, depends on the species and ecology of the zooplankton. Small zooplankton distributing in the shallow layer produce small fecal pellets, and they are usually degraded in the shallow layer. Therefore carbon dioxide is recycled within the sea/atmosphere interface layer of the ocean, and can potentially return to the atmosphere. On the other hand, large zooplankton produce large fecal pellets. Most of their bodies and feces quickly sink into the deep layer. Large plankton are also selectively consumed by large predators, such as fish and whales. These predators can swim extensively both horizontally and vertically, and their bodies sink to the deep layer rapidly after their death. Through these processes, inter-specific relationships affect the ocean ability to absorb carbon dioxide and transport it into the deep layer. In order to monitor the relationships between climate change and biological processes, extensive zooplankton samples which have been collected over a long-time period are necessary, however such zooplankton collections are quite rare in the world. In the North Atlantic Ocean, the CPR (Continuous Plankton Recorder) project has been carried out since 1946 (sample numbers are over 170,000), and precise atlases, including phytoplankton, are already published (Edinburgh