Effects of two organophosphorus insecticides on the chlorophyll a and pheopigment concentrations of standing ponds

✍ Scribed by M. H. Papst; M. G. Boyer

• Book ID: 104622442
• Publisher: Springer
• Year: 1980
• Tongue: English
• Weight: 311 KB
• Volume: 69
• Category: Article
• ISSN: 1573-5141
• DOI: 10.1007/bf00046799

✦ Synopsis

Changes in time in chlorophyll a and pheopigments of ponds treated with the organophosphorus insecticides Abate® and Dursban® were compared with those in untreated but otherwise similar ponds . Treated ponds consistently exhibited a severalfold increase in chlorophyll a, 30 to 5o days following application.

Pheopigment concentrations did not decline in treated ponds and were frequently higher than in control ponds . Increases in pheopigment concentration could be correlated with increased numbers of microzooplankton following treatment .

It is suggested that microzooplankton, increasing in numbers as a result of the reduction in macrozooplankton competitors, sustain grazing activity for a considerable period after the pesticides have been applied. These data support and extend the conclusions of others that release from predation is an important factor in the increase in algae following treatment with organophosphorus pesticides .