Background

　The Arctic Ocean has been experiencing rapid warming in recent years. The effects of global warming on marine ecosystems are first seen in the plankton that make up the lower-order marine ecosystems, which have short generation times. However, the seasonal freezing of the Arctic Ocean makes it difficult to collect plankton samples throughout the year, and little is known about their life histories. In order to collect plankton samples throughout the year, it is effective to establish a fixed station on the ice and conduct time-series sampling. The most successful time-series plankton collection ever conducted using a fixed station on ice was the research project "SHEBA," which used an icebreaker in Canada as an observation base from October 1997 to October 1998 (see figure below). The zooplankton samples collected during this project are referred to as SHEBA plankton samples. The life history of "particle-feeding copepods (zooplankton that feed on phytoplankton)" was reported by researchers at the Woods Hole Oceanographic Institution, but the life histories of other species remained unclear.