PORTLAND — Maine scallop fishermen are kicking off a season that’ll last 70 days along most of the coast.

But fishermen in the scallop-rich waters of Cobscook Bay along the Canadian border in far eastern Maine will be limited to a 50-day season. The season opened Monday in three zones from Kittery to Lubec.

Maine’s scallop fishermen operate under a regulatory system that divides the state into three zones with restrictions and closures in a number of areas aimed at allowing scallops to replenish.

Marine Resources Commissioner Patrick Keliher says the restrictions have been challenging but they’re working. Fishermen last year hauled in 2.4 million pounds, the best harvest in a decade. The catch was worth $3.2 million