PORTLAND, Maine — After 24 years, longtime Casco Bay baykeeper Joe Payne will retire from Friends of Casco Bay in January, Payne announced Thursday.

Payne was the first baykeeper for Casco Bay and the seventh waterkeeper in the world, according to Mary Cerullo, associate director of Friends of Casco Bay. Payne works to respond to citizen concerns, resolve pollution problems that threaten the bay and advocates for compliance with environmental laws.

“He kind of birthed our organization,” she said.

Payne, grandson of a fisherman, was raised on Peaks Island and studied marine biology.

During his tenure, he created an award-winning volunteer water quality monitoring program and made Casco Bay one of the most thoroughly sampled water bodies in the country, according to the U.S. Environmental Protection Agency. That work allowed hundreds of clam flats to reopen to harvesters after sources of fecal coliform pollution were identified and eliminated.

Payne also organized a mobile pumpout service for recreational boats, keeping more than 125,000 gallons of raw sewage out of the bay, according to Friends of Casco Bay.

Payne is known for his collaborative approach in promoting clean waters, Cerullo said. In larger cities, such as San Francisco and New York, “the only way they can get people’s attention is to threaten to sue them,” she said. “Here in Maine, that only works once. So Joe has a different model. He’s as collaborative as he can be, and if [necessary], then he puts on his boxing gloves. And that approach has just worked wonders. Joe is welcome in all sorts of arenas because he’s reasonable, but he knows the bottom line is protecting the bay.”

In May 2012, Payne received an environment merit lifetime achievement award from the U.S. Environmental Protection Agency. Describing Payne’s passion for his work, the EPA wrote, “Few people can match Joe Payne’s lifetime advocacy for clean water. … His science-based, collaborative approach to resolving threats to the bay’s environmental health continues to be effective.”

Payne will become “Casco Baykeeper Emeritus,” he wrote in the letter announcing his plans to retire. He will continue to volunteer with the organization and work with the next baykeeper, according to the letter.

Cerullo said the process to fill Payne’s “really big shoes” will likely take several months. Payne has built such a foundation for the organization, she added, that the new baykeeper will have many opportunities to continue to protect the bay.

“By working together, we as a community have built a strong organization dedicated to protecting the health of Casco Bay,” Payne wrote Thursday. “Thanks to our volunteers, supporters and staff, I can say that our waters are healthier and better protected than they were 2½ decades ago. Unfortunately, the job isn’t done. There are problems that are going to take all of our work and support to solve.”