title: Algal growth inhibition by river water pollutants in the agricultural area around Lake Biwa, Japan.
abstract: An ecotoxicological study of river water discharged from the agricultural area around Lake Biwa was performed by using algal bioassays to guide chemical analysis. Water samples were collected once a week, at least, for 1 year starting in April 1997 and continuing until April 1998. The toxicities of the dissolved and particulate-adsorbed extracts of water samples were evaluated by the algal growth inhibition test and concentrations of individual pesticides were determined. Most of the river water that was collected during the periods when pesticides were applied to the paddy fields caused algal growth inhibition. Some extracts were found to contain herbicides (molinate, mefenacet, simetryn, or esprocarb) as major compounds. According to chemical assay and bioassay, simetryn was identified as the most toxic compound that caused algal growth inhibition.
authors.affiliation: Research Institute for Bioresources, Okayama University, Chuo, Kurashiki, Japan. hokamura@rib.okayama-u.ac.jp
authors.forename: Hideo
authors.initials: H
authors.lastname: Okamura
authors.forename: Mingyu
authors.initials: M
authors.lastname: Piao
authors.forename: Isao
authors.initials: I
authors.lastname: Aoyama
authors.forename: Miki
authors.initials: M
authors.lastname: Sudo
authors.forename: Takuya
authors.initials: T
authors.lastname: Okubo
authors.forename: Masahisa
authors.initials: M
authors.lastname: Nakamura
mesh_terms: D000383:Agriculture / Q000379:methods; D000818:Animals; D029064:Araceae / Q000187:drug effects; D001681:Biological Assay; D000460:Chlorophyta / Q000187:drug effects* / Q000254:growth & development; D003621:Daphnia / Q000187:drug effects; D004463:Ecology; D005618:Fresh Water / Q000032:analysis*; D007564:Japan; D018545:Lactuca / Q000187:drug effects; D010575:Pesticides / Q000032:analysis / Q000633:toxicity*; D012621:Seasons; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D014877:Water Pollution, Chemical / Q000032:analysis
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical