CORNWALL, Ont. – A strike by workers on the St. Lawrence Seaway could be just a few days away.

Five Unifor locals along the seaway from Niagara to Montreal announced Tuesday they were serving 72 hours’ strike notice along the waterway.

The union says one of the key issues in contract talks is staffing levels at the locks as the seaway moves to hands-free mooring, eliminating staff currently working on the locks.

The union is calling for minimum staffing levels on the locks to deal with emergencies.

Strike notice was served at the resumption of contract talks in Cornwall, Ont., the first time the two sides had met in months.

Unifor filed for federal conciliation in August, and the earliest a strike could begin is this Friday at 12:15 p.m.

The workers earlier voted 96 per cent in support of a strike.

The five union branches along the St. Lawrence Seaway – Locals 4212 and 4211 in Niagara and Cornwall, Locals 4319 and 4320 in Montreal and Local 4323 in Iroquois – have about 460 members.

“The communities along the seaway benefit both from the good jobs it provides, and the work our members do to keep the waterway safe,” Unifor National Representative Joel Fournier said in a release.

“We believe that having no one at the lock is not a good idea,” said Fournier. “The risk of an environmental disaster with all of the dangerous cargo going through the Seaway is very real.”

The St. Lawrence Seaway, which extends from Montreal to mid-Lake Erie, includes 13 Canadian and two U.S. locks.