MP5 Agrochemicals and Pesticides
Monday, 14 November 2005: 8:00 AM - 5:30 PM in Exhibit Hall

(HEW-1117-830643) Assessing runoff impacts on aquatic ecosystems in Atlantic Canada.

Hewitt, L¹, Batchelor, S¹, Rees, H², Chow, L², MacRae, A³, Edwards, L³, Jardine, C⁴, Teather, K⁴, ¹ National Water Research Institute, Burlington, ON, Canada² Potato Research Centre, Fredericton, NB, Canada³ Crops and Livestock Research Centre, Charlottetown, PEI, Canada⁴ University of Prince Edward Island, Charlottetown, PEI, Canada

ABSTRACT- As part of ongoing studies in Atlantic Canada on the fate and effects of potato pesticides, we have established protocols for regular collections of surface waters in a small (Black Brook, NB) and large watershed (Wilmot River, PEI), both areas of intensive potato production. We also established the collection of runoff in Black Brook and at a field scale site where a runoff flume with autosampler has been developed and installed. Work on effects-based assessments has resulted in the development and validation of a Japanese medaka bioassay to study sediment-related toxicity. Our studies have resulted in the development of a multi-residue method for pesticides on a new LC-MS-MS system. With the new method we have provided the first information from systematic sampling of surface waters for pesticides in both watersheds and are showing significant inputs for linuron and imidacloprid are occurring via runoff. Medaka assays have shown the ability to reproduce toxicity with whole sediments retreived from areas affected by intensive potato agriculture and is being used to investigate causative factors.

Key words: runoff, pesticides, potato, cause and effect