PW12 Pesticide II
Exhibit Hall
8:00 AM - Wednesday
(PW201) Effects of glyphosate on olfaction in juvenile coho salmon, Oncorhynchus kisutch.
Tierney, K1, Jarrard, H1, Ross, P2, Kennedy, C1, 1 Simon Fraser University, Burnaby, BC, Canada2 Fisheries and Oceans Canada, Sidney, BC, Canada
ABSTRACT- Olfaction is a critical sensory ability in anadromous salmonids and therefore, sublethal exposures to pesticides known to interfere with sensory perception and behavior can impact overall organism performance. The effects of the herbicide glyphosate (N-(phosphonomethyl) glycine) on salmonid olfaction were measured using electroolfactograms (EOG; underwater nasal trans-epithelial voltage) in 0-year coho salmon, (Oncorhynchus kisutch). EOGs were measured prior to and following exposure of the olfactory rosette to various concentrations of the herbicide. Significant reductions in EOG responses to the odorant L-serine occurred with exposure and were correlated to both exposure time and chemical concentration. Significant reductions in EOG were not consistent across all concentrations of L-serine presented to the rosette. Recovery of EOG responses post-exposure were glyphosate concentration-dependent, and at 70-min post exposure not all concentrations recovered to 100%. However, exposure of the rosette to high concentrations of glyphosate, which completely eliminated any EOG response, showed recovery to the same level as all other concentrations. This suggests that there may be several mechanisms of pesticide-mediated olfactory impairment involved, one that is transient, and another which results in more permanent damage to the olfactory epithelium. These results indicate that glyphosate is an olfactory toxicant which can reduces EOG responses and can potentially affect olfactory-mediated behaviors in Pacific salmonids.
Key words: salmonids, olfaction, glyphosate, herbicides