2021 Volume 34 Issue 1 Pages 151-167
According to the introduction of the Total Pollutant Load Cotrol System for Ise Bay, a part of the water quality has gradually improved, although the demarshal fish production including shellfishes at the bay has been declining until recently. The richness of the bay existed before 1960s has been lost as well as the other water basin in Japan. The Japanese government initiated the work for restoring clean and rich ocean as a countermeasure for this situation. A research project by Mie Prefecture in Japan was then carried out in this movement and the richness of the marine organisms of every trophic level in the ecological pyramid was studied, mostly through literature surveys. This article reports a part of the survey results and describes the variation of zooplankton community in the bay over the years. As the miniatualization of the phytoplankton in the bay was reported in the author’s previous work[16], this new study also indicated the increase of the smaller species of copepoda, a member of zooplankton. The miniatualization of the phytoplankton as well as the zooplankton could cause the basic change of the food-web structure and could affect the production of the higher trophic level creatures such as the commercially important fishes. The further study is planed in the research project to draw a firm conclusion.
