토픽 개요
Northward shift of plankton community
- The stations were dividied into six groups (A-F), and northward shift was observed in 2007/2008.
- In 2007, new group D was only seen with dominance of Pacific copepods.
- This trend was also reported by another paper from longer observation.
Plankton sampling and experiment on research vessel
- Fresh females were picked up from net sample.
- The specimen was incubated at in-situ temperature (0ᵒC) on board, and the reproduced eggs were counted
- The eggs were incubated until hatching.
- Successful reproduction by pacific copepods were confirmed.
The number of eggs were similar to that of Pacific.
- Hatching rate was very low at 7.5%, which is normally 90% in Pacific.
- It could be caused by the unfertilized eggs were abundant in the reproduced eggs.
- Because of that, establishment of the pacific copepods in Arctic is difficult so far.