The effect of dursban upon fresh water phytoplankton

Toxicity of pesticides to aquatic microorganisms: A review

“…Blooms of cyanobacteria (Anabaena, Anabaenopsis) occurred at both concentrations tested. At a normal application concentration of 1.2 g/L, chlorpyrifos caused persistent (up to 17 d following the initial application) reduction in growth of most phytoplankton in a freshwater pond community [48]. Chronic exposure of Anabaena sp.…”

Ecotoxicology of Chlorpyrifos

“…Phytoplankton abundance remained depressed relative to controls for 17 wk . Brown et al (1976) noted that chlorpyrifos effects were dependent on the natural growth cycles of phytoplankton and that growth inhibition was most observable during the active growth phase. Butcher et al (1975Butcher et al ( , 1977 evaluated the effects of a single chlorpyrifos application (emulsifiable formulation; 4-1000 ",giL) on water quality, microbial abundance, and phytoplankton communities (top predator not specified) of small artificial ponds (Ontario, Canada) for 80 d. Chlorpyrifos exposure resulted in greater algal abundance and more persistent algal blooms relative to control ponds; treated ponds exhibited higher pH and dissolved oxygen and lower carbon dioxide than control ponds (Butcher et al 1975(Butcher et al , 1977.…”

“…Concentrations greater than 24 I'g/L completely inhibited growth of all algal species quantified (Brown and Chow 1974). Brown et al (1976) evaluated the effects of a single chlorpyrifos application (nominal concentrations of 1.2, 2.4, 24, or 240 I'g/L) for 9-17 d on phytoplankton communities in cylindrical enclosures placed in a large natural pond (top predator not specified) in Ontario, Canada. Chlorpyrifos exposure resulted in a dose-dependent decrease in the abundance of Ankistrodesmus falcatus, Tetraedron sp., and several other phytoplankton species, while the abundance of Ceratium sp.…”

Influence des traitements phytosanitaires sur les biocoenoses du phytoplancton limnique

“…Les travaux deja cites de Ukeles (1962), Brown et al, (1976) Braginsky et al, (1979, Hansen (1979), Guthrie (1980, , Rajendran & Venugopalan (1983) ont montre que de nombreux herbicides ainsi que des insecticides avaient des effets nocifs a de tres faibles doses sur le phytoplancton.…”

“…Un certain nombre de travaux in vitro ou in situ ayant montre que des herbicides (Ukeles, 1962 ; a et b) et des insecticides (Ukeles, 1962 ;Singh, 1973 ;Brown et al, 1976 ;Meyer et al, 1977 ;Braginsky et al, 1979 ;Hansen, 1979 ;Murray & Guthrie, 1980 ;Rajendran & Venugopalan, 1983) pouvaient avoir des effets negatifs sur le developpement des populations algales. Nous avons compare la richesse specifique et la biomasse du phytoplancton entre les mares de prairies et les mares de champs au cours de deux cycles annuels.…”