If there is great satisfaction in having success at home, there is an even greater reward sharing the gift with others — especially halfway around the world.

Rick Karney, the 60-year-old, longtime executive director of the Martha’s Vineyard Shellfish Group, has just returned from a 25-day trip to Zanzibar, an island off the coast of East Africa, where he and others are working to help the country establish its first shellfish hatchery. It was a working vacation from the Vineyard that Mr. Karney said gave him an opportunity to share his knowledge with people in a developing country, a place where clean running water and electricity are considered precious and out of reach for many.

Here on the Vineyard Mr. Karney raises shellfish at his hatchery on the Lagoon Pond that was built from scratch more than 30 years ago. Through the spring, summer and fall, he raises millions of baby quahaugs, bay scallops and oysters with a small staff. The work is aimed at supplementing the wild shellfish that live in Island coastal ponds.

Winters are quiet on the Vineyard waterfront and that is when Mr. Karney takes his vacation.

And with this recent project his expertise is now world-renowned. “In Kiswahili, their native language, they call me Babu chaza,” Mr. Karney said in an interview this week. He said the phrase translates to “respected elder of shellfish.” Mr. Karney said he was particularly struck by how respectful the people of Zanzibar are of their elders.

His work there was aimed at trying to help the people replenish a cockle shellfish whose scientific name is Anadara antiquata. The shellfish were once hugely abundant but now suffer from overfishing in the tidal waters of Zanzibar.

Mr. Karney said the cockle is unlike anything that is harvested in Vineyard waters; he said it looks like a quahaug with the ridges of a bay scallop.

This marks Mr. Karney’s second trip to Zanzibar; the first was last year to start the hatchery there. The work is part of a three-year project backed by the Island Creek Oyster Foundation and the McKnight Foundation and administered by the Woods Hole Oceanographic Institution. One principal backer is Skip Bennett, who runs Island Creek Oyster Co. in Duxbury.

The project leader is Hauke Kite-Powell, who also lives in Duxbury and works at the oceanographic policy center and has been working in Zanzibar for 15 years.

Mr. Karney said Mr. Bennett’s vision is to share his own successes in raising shellfish globally. Much of the gear used in the new distant hatchery was fabricated in Duxbury at a cost of $10,000, transported to Zanzibar a year ago. The new shellfish hatchery is at the University of Dar es Salaam Institute of Marine Sciences in Stone Town. The hatchery occupies an unused alleyway at the institute. Said Juma Shaaban is the hatchery technician and the project is overseen by Narriman Jiddawi, a professor.

Last month Mr. Karney was present to help with the hatchery’s first spawning. “We ended up getting an outrageous result, over 24 million eggs,” he said. But the major hurdle was trying to keep the newly-spawned shellfish alive. It is hot in Zanzibar with temperatures in the 90s on most days. Without reliable electricity, there is no refrigeration and no way to keep the seawater from overheating, except with bottles of frozen water placed on the spawning table. The lack of running water adds to the challenge.

“Here on the Vineyard, I am sometimes frustrated when it takes days to fix something. Over there it can take weeks to buy a pump. Even buying a pair of scissors is hard. I tell you, it gave me a greater appreciation for the infrastructure we have here on the Vineyard,” Mr. Karney said. “They have a long way to go over there,” he added. When the pump failed, Mr. Karney said they had to carry buckets of seawater from the harbor to the hatchery.

Other challenges for Mr. Karney included adapting to the lifestyle, with open air food markets, no refrigeration and plenty of flies. Mr. Karney said at first he tried being a vegetarian, not feeling confident about eating the meat.

Tourism is growing on the East African island and is part of the driving force behind the hatchery project. “The place is beautiful,” Mr. Karney said. “The east side of the island is pristine, with white sandy beaches. There is a lot of investment, big resorts.” Women are the primary workers in the shellfish industry, and Mr. Karney said in the long run the hatchery may help to better their lives, because the shellfish can be sold in restaurants.

Prior to being overfished, the cockles were harvested by the women of the community, who would walk out onto the tidal flats at low tide. The tides in Zanzibar are extreme, running a span of nine feet, which means extensive areas of shallow tidal flats for cockles habitat. Today they are scarce in the shallows and mostly can be found in deeper water, out of reach. Mr. Karney said the hope is to restore the shellfish to the tidal areas, which would bring economic opportunity back to the people.

The project is under close scrutiny and has the support of the government. While there, Mr. Karney met the country’s second vice president, Seif Ali Iddi, who came to take a tour through the hatchery.

Next year, Mr. Karney plans to make a third trip to Zanzibar to see the hatchery’s progress and help Said Juma Shaaban take the next step toward production on a larger scale.

He said working on the project calls to mind his own early years on the Island when the shellfish hatchery was in its infancy. When he watched the shellfish spawn for the first time in the Zanzibar hatchery, he recalled his own first year raising quahaugs on the Vineyard.

Two weeks ago, shortly after his return to the U.S., Mr. Karney gave a slide presentation on his work at the 31st annual Milford Aquaculture Seminar. More than 80 aquaculture professionals and academics attended the event.

Across New England, Mr. Karney already has earned his title of Respected Elder of Shellfish.