The executive director of the Maine Port Authority, the state agency overseeing harbor operations from Kittery to Eastport, has resigned this week, according to the Portland Press Herald.

John Henshaw, who has served as the head of the authority for a decade, oversaw the $45 million expansion of Portland’s International Marine Terminal and the return of container shipping business there. He has also advocated for a city zoning change that would allow the construction of a taller refrigerated storage facility, which would keep Maine foods cold while awaiting transportation to international markets.

In his resignation letter, Henshaw wrote that he’s leaving at a time when “the future appears bright for the port authority,” according to the Press Herald.

“I believe the momentum is there to carry the facility far into the future,” he wrote, according to the newspaper.