On Main Street in Liverpool, N.S., opponents of salmon farming wave placards at passing traffic.

The signs read, "Save Liverpool Bay! Say No! Open-Pen Fish Farms."

Some vehicles honk in support, but many others do not during a recent afternoon in the South Shore community.

The former pulp mill town is now ground zero in a renewed debate about coastal salmon farms.

"Too many fish die, there's disease. It's not a clean business and it's just not right for Nova Scotia," said Brian Muldoon.

He lives opposite an existing salmon farm in Liverpool Bay and is leading the campaign against expansion plans by Kelly Cove Salmon, a subsidiary of aquaculture giant Cooke Seafood.

Muldoon said there are 14 pens at Coffin Island, which hold 400,000 fish, and that Cooke wants to increase it to 60 pens and 1.8 million fish.

"Our bay is too shallow for this. It just can't hold it. It is too shallow to flush," said Muldoon.