He began more than 40 years ago when shellfish management was a term no one had ever heard of.

Now Rick Karney, the longtime executive director of the Martha’s Vineyard Shellfish Group, will retire from the top post at the nonprofit he helped build from the ground up.

Or mostly retire. In his annual letter to donors that went out this week, Mr. Karney announced that he will shift to part-time status beginning Jan. 1.

“I still love my job but I don’t love it seven days a week. It’s time,” Mr. Karney told the Gazette by phone Monday afternoon.

Mr. Karney will turn 66 this month. He said a plan is in place for his chief assistants, Amandine Surier and Emma Green-Beach to take over the running of the hatchery. Exact titles are still being worked out. “They are going to be equal partners,” Mr. Karney said. Chris Edwards, another staffer who has taken over responsibilities for facility maintenance at the solar hatchery in Vineyard Haven, will also play a key role going forward, he said.

Mr. Karney: "It's unretirement." — Mark Lovewell

Mr. Karney came to the Vineyard from Virginia in 1976 as young biologist, hired by the late Michael Wild who was the coastal planner for the Martha’s Vineyard Commission. Mr. Wild wanted Mr. Karney to assist the shellfish constables in the six Island towns. At the time there was no regional program, no hatchery and aquaculture was a novel idea in a place where the wild shellfish were abundant, the water unpolluted, the surrounding land sparsely developed.

“Back then it was pretty radical,” Mr. Karney said recalling his early days of working on the Island. “I remember the first closure in Katama Bay [for protecting seed shellfish]. That was unheard of.”

Today the shellfish group is a thriving regional program funded by the six Island towns that among other things helps manage and restock the shellfish populations in saltwater ponds and harbors.

“The shellfish group has grown up with the community and the community has grown up with us,” Mr. Karney said. “It’s taken many years to develop that.” He continued: “The wild fishery — I’m pretty happy we are holding our own. And private aquaculture is a bright spot. The farmers are beginning to take a larger role . . . . they are out there every day, and they are seeing that if mother nature can’t do it, then we will do it for ourselves.”

Mr. Karney said he will continue to work at the hatchery, but plans to take a more back seat role. “It’s unretirement,” he said.

He expressed confidence in his successors who have worked closely with him in recent years. “I’m comfortable with them being able to carry this on,” he said. “It’s my baby and I certainly don’t want it to die on the vine. These are people who still feel like I did and do about the place and are willing to give a hundred and one per cent to get things done.”

And he said he hasn’t lost his love for what attracted him to the job in the first place.

“On the first day of scalloping — it gets you right in your heart to see the local people out there and how there still is this passion for scallops, for all shellfish,” Mr. Karney said. “That’s what so neat about the Vineyard and that’s why I’m here, because of the culture and the fact that people see the value in that resource and are willing to put their money where their mouth is.

“It motivates us.”