CORNWALL, ONTARIO (WWTI) — The St. Lawrence Seaway is shut down.

On Saturday, October 21, St. Lawrence Seaway union workers officially went on strike.

The St. Lawrence Seaway Management Corporation and UNIFOR, the union that represents over 300 Seaway workers, recently held contract and salary negotiations. However, the two parties were unable to reach an agreement before the union’s strike deadline, which was 12:01 a.m. on October 22.

UNIFOR’s 72-hour strike notice was officially filed on October 18.

“We negotiated in good faith right up to the last moment, but we cannot allow workers’ rights to be compromised, UNIFOR Quenve Director Daniel Cloutier said in a press release. “We remain open to discussion and hope that the employer will reconsider its position for the good of all.”

The strike resulted in the shutdown of the St. Lawrence Seaway, according to an additional press release from the St. Lawrence Seaway Management Corporation.

An “orderly shutdown” of the Seaway system took place during the 72-hour notice period, which allowed vessels to safely clear the waterway, the press release said. As of October 22, no vessels were waiting to exit the system, but there were over 100 vessels waiting outside the waterway.

“The stakes are high, and we are fully dedicated to finding a resolution that serves the interests of the Corporation and its employees. We remain committed to continuing discussions and reaching a fair labor agreement,” SLSMC President and CEO Terence Bowles said in the press release. “In these economically and geopolitically critical times, it is important that the Seaway remains a reliable transportation route for the efficient movement of essential cargos between North America and the remainder of the world.”

The system will remain shut down until an agreement can be reached, the Seaway confirmed.

Picket lines are currently set up at the St. Lambert Lock in Quebec and Welland Cana in St. Catharines, Ontario.