ONTARIO: Farm manure pollutes Lake Huron

07.may.09
University of Guelph News Service

GUELPH -- Agricultural wastes are the main source of E. coli bacteria
that contaminate a part of Lake Huron prized for recreation, says a new
study by University of Guelph researchers.
Almost two-thirds of the bacteria in the southeastern Lake Huron study
site came from livestock waste, said Prof. Jack Trevors of Guelph's
Department of Environmental Biology. This is the first report to show
how much bacterial pollution comes from different sources between
Goderich and Kincardine.
Livestock accounted for between 59 and 62 per cent of E. coli entering
the lake. The rest came from wildlife, human waste and unknown sources.
Human sewage accounted for one to three per cent, Trevors said.
He co-authored the study with U of G environmental biologist Prof. Hung
Lee and researchers from the Ontario Ministry of the Environment. Their
research paper appeared in the March issue of the Canadian Journal of
Microbiology.
"We know agriculture is important to Ontario," said Trevors. "We're
using scientific tools to learn about the environment and how to sustain
and improve our water resources."
The team compiled DNA samples from potential E. coli sources and
compared those against samples taken in 2005 and 2006 from Lake Huron
and the creeks and rivers feeding it.
Trevors said it's useful to quantify how much bacterial pollution might
come from different sources. "If you don't know where it's coming from,
it's difficult to mitigate the problem and protect recreational water.
If you know where it's coming from, you can try to implement management
solutions to deal with it."