Collaborative research groups such as the Seto Seaside Experiment Station of Kyoto University have conducted research and research on uni for half a century in Hatakejima (Wakayama Prefecture), a nature reserve owned by the university. The impact of sea urchins on the ecosystem was clarified for the first time in the world.
As a result of the survey, the dominant species, Heliocidaris chinensis, Tanishiuni, and Nagauni, which had a large population from the 1960s to the 1970s, decreased sharply from the latter half of the 1970s to the beginning of the 1980s, and then gradually decreased in number. Has recovered.This is thought to have been influenced by the red tide that occurred frequently with the increase in fish farming from the 1960s to the 1970s.In addition, tropical Nagauni are strongly affected by the water temperature in winter.Thus, it became clear that the tendency of long-term fluctuations in sea urchins has an indirect effect on human activities.
The impact of human activity on ecosystems is slow, so long-term continuous monitoring is essential, but it takes time to produce results and research often stops due to lack of funding.The study may also be terminated due to the absence of a successor.In this survey, successive researchers led by the late Dr. Shunichi Ogaki and the late Dr. Naomasa Kobayashi connected the baton and made such a long-term survey possible.
Assistant Professor Tomoyuki Nakano, one of the research workers, says that the half-century of continuous research cannot be completed by ordinary means.This research will be continued for another 50 years, and the effects of global warming on sea urchins will be monitored.
Paper information:[Ecological Indicators] Effects of temperature and red tides on sea urchin abundance and species richness over 45 years in southern Japan. Ecological Indicators
