Red tides in Hokkaido in the past
章节大纲
-
Time of emergence Sea area Causal species Estimated cause of occurrence September, 1972 off the mouth of the Tokachi River dinoflagellates the genus Gymnodinium After heavy rainfall, the river outflow was followed by a series of calm days, which allowed river-derived nutrients to accumulate near the sea surface.
September, 1983 Urahoro-cho to Erimo-cho dinoflagellates the genus Gymnodinium same as above September, 1985
off the mouth of Tokachi River to Taiki Fisheries Port dinoflagellates the genus Gymnodinium and Prorocentrum same as above September, 1986 off the mouth of Rekifune River to mouth of Toyoni River raphidophytes Heterosigma akashiwo same as above October to November, 2015 Hakodate Bay dinoflagellates Karenia mikimotoi A part of the red tide that occurred on the Japan Sea side, such as Kyushu and San-in migrated on the warm Tsushima Warm Current and proliferated.
July, 2016 Hakodate Bay raphidophytes Heterosigma akashiwo July, 2018 Hakodate Bay raphidophytes Heterosigma akashiwo September to November, 2021 Pacific coast of east Hokkaido dinoflagellates Karenia selliformis