Protecting Bali's Lush Reefs

Just a short hop from Bali’s southern peninsula, the tiny island of Nusa Ceningan feels worlds away from the mainland buzz of motorbikes and beach clubs. Here, aquamarine shallows slip into the deep-blue drop-offs of the Nusa Penida Marine Protected Area, where cold-water currents flowing between the Pacific and Indian oceans deliver a steady flush of nutrients that keeps corals colorful and marine life thriving.

Onshore, Ceningan Divers stands out for pairing aquatic adventure with sea stewardship. Since opening in 2015, the PADI Five Star IDC Resort has earned a loyal following of eco-minded divers and a growing list of conservation accolades, including the Green Fins Award from the Reef-World Foundation in 2025 and multiple wins at the annual BlueGreen360 Awards—Resort of the Year in 2019 and Dive Operator of the Year in 2018.

Co-owner Matt Hutchinson says every diver arrives hoping for two bucket-list encounters: manta rays and mola mola. The famed Manta Point offers year-round sightings of reef mantas gliding through nutrient-rich waters to feed and be cleaned. Each manta’s belly pattern is like a fingerprint, forming the foundation of a photo-ID project supported by divers and the Marine Megafauna Foundation. With the help of citizen scientists, the dive center has identified more than 870 mantas, with some migrating an astonishing 275 miles between Nusa Penida and Komodo.

“Divers have helped identify around 80 new mantas by submitting belly-pattern photos,” says Hutchinson. “It’s fantastic to see the population growing and holding steady.”

Between July and October, the mysterious mola mola, or ocean sunfish, makes its seasonal appearance. These colossal plankton eaters—which can measure as long as 11 feet and weigh up to 5,000 pounds—arise from the deep to be cleaned in shallower waters.

Related Reading: 10 Amazing Facts About Manta Rays

Beyond the giants, the reefs teem with turtles, crustaceans, reef sharks and fish that take refuge in the corals. At Gamut Bay, the dive center’s PADI AWARE Adopt the Blue site, small critters and juveniles have begun to recolonize after damage caused by pollution and storms.

Ceningan Divers’ team has built artificial reef structures to rehabilitate storm-damaged sites, experimenting with materials to study coral adhesion and growth. “We’re testing, collecting data and learning which methods bring the best results,” Hutchinson explains. Collectively, the team’s efforts have contributed to more than 200,000 coral fragment transplants across the islands.

And in 2024, a team of Indonesian marine biologists from Ocean Gardener—an organization working to restore Bali’s coral reefs—joined the Map the Giants project, which surveys exceptionally large coral colonies all over the world. Off northern Nusa Penida, researchers discovered an immense Galaxea astreata coral colony measuring roughly 230 feet long and more than 160 feet wide, making it potentially the largest individual coral colony on Earth. Genomic testing is now underway to confirm its status.

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The center runs more than a dozen citizen science and education programs, many open to recreational divers at no cost. Guests can photograph mantas, mola mola and turtles for ID databases; monitor reef health; or take part in coral-spawning observations. Others join artificial reef, clownfish and giant-clam dives, or work toward their PADI Underwater Research Diver course.

“Our goal is to educate through science and experience,” says Hutchinson. “The more people understand, the more they care.”

The dive center offers scholarships to Indonesian divers to assist their careers in the marine eco-tourism space as dive professionals, guides or researchers. Scholarship winners commit to a two-year program that includes extensive PADI Divemaster training and a year-long employment contract with Ceningan Divers.

Above the waves, Ceningan Divers’ eco-efforts continue. Weekly community cleanups, organized in partnership with local volunteers, have collected roughly 15 tons of land-based waste and 2 tons from the ocean in 2025 alone.

By mobilizing both staff and locals, Ceningan Divers is fostering a new environmental culture in a region where government recycling infrastructure is still limited, helping keep plastic from entering the currents that feed the island’s reefs.

Ceningan Divers’ mangrove restoration program also begins in-house. Seeds are harvested, propagated in a nursery until mature and then replanted along vulnerable shorelines—a process that takes four to six months but yields high success rates. Essential to the local marine ecosystem, these mangroves protect the coast from erosion, capture and store carbon, and provide nursery habitats.

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After a day spent diving with mantas or restoring coral, divers return to a resort that reflects the same eco-principles found below the surface.

The property was built largely from sustainable materials and is shaded by large thatched roofs. Two pools, a well-kept garden and plenty of areas to lounge make it a relaxing place for surface intervals.

Within the more practical elements of dive resort operation, Ceningan Divers has slashed its use of single-use plastics, uses eco-friendly cleaning solutions and reef-safe suncare products, and educates its guests on appropriate behavior around marine wildlife.

Evenings often end with guests swapping dive tales over drinks, reviewing manta ID photos, playing board games or signing up for the next day’s reef survey. For many, what begins as a dive holiday evolves into a deeper connection with the ocean and a desire to protect it.

Hutchinson believes this is where meaningful change begins: “Every diver who visits becomes part of something bigger. They leave not just with memories of incredible dives, but with a new awareness of how fragile and interconnected our ocean really is.”