Algal growth inhibition by river water pollutants in the agricultural area around Lake Biwa, Japan.
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.
Okamura
Hideo
H
Research Institute for Bioresources, Okayama University, Chuo, Kurashiki, Japan. hokamura@rib.okayama-u.ac.jp
Piao
Mingyu
M
Aoyama
Isao
I
Sudo
Miki
M
Okubo
Takuya
T
Nakamura
Masahisa
M
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
D010575:Pesticides; D014874:Water Pollutants, Chemical