Strict new regulations are needed to control the growth of mink farms in southwest Nova Scotia, some local residents say.

A proposal for a mink farm at Sloans Lake is opposed by people who suspect existing ranches in Digby County are responsible for large blue-green algae blooms in a local river system.

Randy Cleveland, from Carleton, said new rules are needed before a decision is made about another mink farm in the area.

Farming practices haven't kept up with the growing industry, said Cleveland, who's part of a group researching the algae bloom issue.

"It was OK when you had 1,000 mink on your ranch. The pressure on the environment and on the water system was somewhat minimal then. But when you have one million mink up there, the pressures from an environmental point of view have just gone off the scale," he said.

About half of the mink farms in Canada are in Nova Scotia. The number of animals has tripled over the past 10 years, to about one million.

Leo Muise, executive director of legislation and compliance with the Department of Agriculture, said department staff are working on new regulations to control growth of the mink industry.

Muise said environmental farm plans are about three years old.

"That's another tool to deal with these environmental issues, anything from fuel storage to chemical storage and manure handling and the like," he said.

Provincial officials are trying to identify the source of this summer's large algae bloom.