Buffers not enough to stop fish kills: biologist

Buffer zones intended to protect P.E.I. waterways from pesticide runoff need to be enhanced with other measures, says the biologist who reported the first of two fish kills discovered in eastern Prince County this week.

Regulations put in place following a number of serious fish kills from 2002 to 2004 require a 10-metre grass buffer zone between fields and waterways, and a number of other voluntary measures were suggested.

Daryl Guignion, a biology professor at UPEI, is calling on the province to make some of those voluntary measures mandatory, in order to prevent future kills.

"Buffer zones help. But they're not the sole answer," Guignion told CBC News Tuesday.

"If you have a long potato field, say it's a half kilometre long, tipped down toward the river, no width of buffer is going to stop that volume of water in a heavy rainfall event."

Guignion suspects a buffer zone around a potato field may have been breached by the heavy rain last Saturday, carrying pesticide into the Dunk and Tryon rivers. Provincial officials said Tuesday they had hoped buffer zone laws would prevent this.

When fields are sloped, said Guignion, terracing, strip cropping and wider grass waterways should be used to help block the flow of water. Right now, these are voluntary measures only. Guignion believes they should be mandatory.

But Environment Minister George Webster says it's too early to say what recommendations, if any, may be made after the latest incidents.

"We are making progress on this particular issue," said Webster.

"It's just very, very unfortunate that we did get a heavy rainfall event, and it seems that our systems just didn't quite hold up in that extreme event."

Webster says investigators are checking to see that farms adjacent to the fish kills do meet the buffer zone legislation. All farms that have been checked so far are in compliance.

Environment officials have also been checking rivers around the province to see if last weekend's heavy rain resulted in other fish kills, but none have been found.