Occurrence of glyphosate in surface waters of Southern Ontario.

Glyphosate in surface waters of southern Ontario (Canada) was studied over a 2-year period. A small percentage of samples exhibited glyphosate concentrations greater than the analytical limit of quantitation (17 microg a.e.

Chemical and biomonitoring to assess potential acute effects of Vision herbicide on native amphibian larvae in forest wetlands.

In conjunction with operational forest herbicide spray programs in Ontario, Canada, chemical and biological monitoring studies were conducted in 51 different wetlands to quantify the probability and magnitude of contamination by a glyphosate herbicide formulation (Vision). Wetlands were classified as oversprayed, adjacent, or buffered in relation to the operational target spray blocks. Results show that vegetated buffers significantly mitigated against exposure and thus potential for acute effects.

Effects of Vision herbicide on mortality, avoidance response, and growth of amphibian larvae in two forest wetlands.

The effects of Vision (glyphosate, 356 mg acid equivalents (a.e.)/L) on mortality, avoidance response, and growth of larval amphibians (Rana clamitans and Rana pipiens) were investigated using in situ enclosures deployed in two forest wetlands of northern Ontario, Canada.

Effects of lethal and sublethal concentrations of the herbicide, triclopyr butoxyethyl ester, in the diet of zebra finches.

Lethal and sublethal effects of dietary triclopyr butoxyethyl ester (TBEE) on zebra finches (Poephila guttata Gould) were determined in laboratory experiments conducted between 8 January and 1 May 1991. The 8-day median lethal dietary concentration, LC50 (95% confidence interval), of TBEE to zebra finches was 1,923 (1,627 to 2,277) mg/kg. In the sublethal effects experiment, when birds were exposed to 500 mg/kg TBEE in the diet for 29 days, food consumption and body weight were significantly depressed (P < 0.