Effects of VISION®, glyphosate, on progeny of wood frogs exposed in conifer plantations

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Glaser, Janine Damaris
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University of Guelph

I investigated the effects of aerially sprayed glyphosate (VISION\sp\circler formulation) on the progeny of wood frogs (Rana sylvatica) residing in treated conifer plantations. About 15 egg masses per site were sampled from five treatment types in northern Ontario, Canada. Plantation treatments included reference (n = 5); mechanically disturbed only (n = 5); sprayed once with 1.44 kg glyphosate a.e./ha (n = 5); sprayed once with 1.8 kg glyphosate a.e./ha (n = 5); and sprayed once with each of 1.44 and 1.8 kg glyphosate a.e./ha (n = 4). Egg masses collected from VISION\sp\circler treated areas had smaller post-hatch lengths, smaller juvenile lengths and masses, and larger % post-hatch deformities. Survival to hatch and metamorphic, juvenile, and cumulative deformity did not differ among treatments. The possible effects of VISION\sp\circler were most likely maternal and short-term; however, its effects in areas where it is used annually should still be investigated.

aerial spray, glyphosate, VISION, wood frogs, Rana sylvatica, conifers