HALIFAX -- A fishing vessel sank Saturday as Canada's largest and most lucrative lobster fisheries opened off Nova Scotia, but all crew members were reported safe.

Fisheries Department spokeswoman Debbie Buott-Matheson confirmed a lobster fishing vessel sank in Hackett's Cove, roughly 45 kilometres southwest of downtown Halifax, Saturday morning.

Joint Rescue Coordination Centre spokeswoman Maj. Amber Bineau said the vessel's four crew members were wearing life jackets and were rescued by a nearby fishing vessel.

Keith Laidlaw, deputy superintendent for the Canadian Coast Guard's environmental response team, was not able to say why the vessel sank.

He said it was being removed from the water Saturday afternoon.

"Apparently the vessel was full of fuel because they were just heading out," Laidlaw said in an interview. "We do have a release of pollutants from the vessel. There was a hydraulic tank of approximately 30 to 40 litres."

Laidlaw said the fuel was being contained and cleaned up using absorbent material. A skimmer, which removes oil from the surface of the water, was also being used.

Hackett's Cove is part of Lobster Fishing Area 33, which extends from Halifax to the southwestern tip of Nova Scotia.

That fishery opened at about 7 a.m. Saturday, while Lobster Fishing Area 34 -- which includes roughly 970 boats that work the waters off the province's western edge -- opened at about 6 a.m.

The season was supposed to start last Monday, but industry associations that represent about 6,000 fishermen called for a delay because the forecast was calling for rain, snow and strong winds throughout the week.

Buott-Matheson said if wind speeds are expected to exceed 46 kilometres per hour, opening is automatically delayed.

However, if the forecast does not offer a definitive picture, the final decision rests with the representatives from each fishery.

Lobster was the province's top seafood export in 2017 at $947 million.

According to a recent senate committee report, Canada's commercial fishing industry has the highest fatality rate of any Canadian job -- an average of one death per month.