title: Diffusion of microcystins (cyanobacteria hepatotoxins) from the reservoir of Isahaya Bay, Japan, into the marine and surrounding ecosystems as a result of large-scale drainage.
abstract: In the artificial reservoir of the Isahaya reclaimed land, Nagasaki, Japan, algal blooms have become an annual event, dominated primarily by the microcystin (MC) producing cyanobacteria Microcystis aeruginosa. Although the majority of MCs are either degraded by bacteria or washed out to sea, some remain in the sediment of the reservoir and bay throughout the year. As a result, they also accumulate in aquatic organisms (mullet, oyster, etc.) that inhabit the reservoir and surrounding areas, as well as midge flies that spend their larval period in the bottom of the reservoir. Accordingly, MCs also accumulate in the predators of these organisms, allowing the toxin to spread from the hydrosphere to terrestrial ecosystems. The most effective method for resolving this potentially dangerous condition is to introduce seawater into the reservoir by opening the drainage gates at high tide.
authors.affiliation: Kumamoto Health Science University, 325 Izumi-machi, Kumamoto City 861-5598, Japan. Electronic address: chatran@icloud.com.
authors.forename: Tohru
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Environmental Research and Management Center, 1-5-3 Kagamiyama Higashi-Hiroshima Hiroshima University, 739-8513, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Umehara
authors.affiliation: Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto City 862-8502, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tsutsumi
mesh_terms: D000818:Animals; D061006:Bays / Q000032:analysis; D000458:Cyanobacteria / Q000378:metabolism; D017753:Ecosystem; D004784:Environmental Monitoring; D005068:Eutrophication; D057097:Harmful Algal Bloom; D007564:Japan; D052998:Microcystins / Q000032:analysis*; D046931:Microcystis; D012623:Seawater; D014881:Water Supply / Q000032:analysis*
chemical_list: D052998:Microcystins; C078588:microcystin
keywords: Bioaccumulation; Cyanobacteria; Isahaya Bay; Microcystin; Sedimentation