Review and synthesis of Carnation Creek herbicide research

Carnation Greek Watershed (48°54′N,125°01′W), located on the west coast of Vancouver Island, was aerially treated with glyphosate (ROUNDUP 1 ) in September 1984. Various chemical and biological studies were conducted for up to 3 years after the treatment in order to study the environmental fate and impacts of the herbicide in a temperate coastal rain forest. In tributaries oversprayed with the herbicide, impacts on coho salmon (Oncorhynchus kisutch) and other aquatic organisms were short-term, and the impacts were considered to be acceptable. Residue movements within the watershed and residue inputs into the aquatic ecosystem were monitored in relation to autumn and winter storms. Glyphosate residues rapidly dissipated and degraded in the natural environment. After 1 year, remaining residues were strongly adsorbed to organic matter, soil particles, and/or stream bottom sediments, where they appeared to be inactivated and immobilized. Key words: ROUNDUP, glyphosate, environmental fate, aquatic impacts, herbicide efficacy, residues, coho salmon, buffer strips.