If you’ve dived here in Dauin, you’ve likely noticed the rich tapestry of marine life that thrives beneath the surface. At Atmosphere Resorts and Spa, we’re fortunate to sit at the heart of the Coral Triangle – the most biodiverse marine region on the planet. But what many visitors don’t realise is that the breath-taking coral reefs they explore are part of a larger, interconnected system that includes two equally important – and often overlooked – habitats: seagrass beds and mangrove forests.
These three coastal ecosystems – reefs, seagrasses, and mangroves – work together to support one another in a delicate balance. Understanding how they connect not only deepens our appreciation for the natural world but also highlights the importance of protecting each link in the chain.
A Trio of Ecosystems
Coral Reefs: The Rainforests of the Sea
The reefs just off the coast of Apo Island are famous for their incredible variety of marine life, from technicolour nudibranchs to giant frogfish and graceful turtles. These structures are built over thousands of years by tiny coral polyps and provide shelter, breeding grounds, and hunting territory for countless marine species. But coral reefs are also fragile – easily damaged by warming seas, pollution, and physical destruction.
The reefs of Apo Island provide shelter, breeding grounds, and hunting territory. Photo by Magnus Lundgren
Seagrass Beds: The Hidden Powerhouse
Often overshadowed by flashier coral gardens, seagrass meadows are shallow, coastal areas covered in flowering marine plants. Here in the Philippines, species like Enhalus acoroides (tape grass) and Thalassia hemprichii (spoon grass) are common. These underwater lawns stabilize sediments, improve water quality by filtering nutrients, and provide food and shelter for species like sea turtles, pipefish, and juvenile reef fish.
Seagrass beds are a hidden powerhouse! Photo by Imran Ahmed
Mangrove Forests: Coastal Guardians
Mangroves, with their tangled roots and muddy terrain, may not seem glamorous at first glance, but they are ecological superheroes. Found in intertidal zones like nearby Bais Bay or the coastlines of Siaton, these forests protect shorelines from erosion and storm surges, trap sediments and pollutants, and act as nurseries for young fish and crustaceans. Their complex root systems provide safe havens for juvenile reef species before they migrate to deeper waters.
Mangroves are ecological superheroes! Photo by Dileesh Kumar
One Connected System
What ties these ecosystems together is a flow of energy, nutrients, and life. Many marine species depend on all three habitats during their life cycles. A young snapper, for example, may begin life in a mangrove nursery, grow in seagrass beds, and eventually live on a coral reef as an adult. If one habitat is damaged or disappears, the entire cycle is disrupted.
Nutrient Cycling
Mangroves trap sediments and organic matter, some of which is broken down and washed out to sea, providing nutrients that seagrasses and corals need. Seagrasses stabilize the seabed and keep waters clear, allowing sunlight to reach coral reefs. Reefs, in turn, help shield seagrasses and mangroves from strong waves and storm damage. It’s a mutual support system built over millennia.
Species Migrations
Many marine creatures are seasonal or daily commuters. Reef fish lay their eggs near seagrasses, while juvenile fish seek the protection of mangrove roots before heading to deeper reefs. Sea turtles feed on seagrass meadows and rest on coral bommies, while species like the sweetlip or jack may hunt across all three habitats depending on their needs and the tides.
The perfect resting place for sea turtles! Photo by Renee Capozzola
The Philippine Connection
The Philippines is home to more than 500 species of coral, ~16 species of seagrass, and more than 40 species of mangroves. Here in Negros Oriental, the synergy between these habitats is on full display. Apo Island’s reefs, Dauin’s coastal muck sites, and the mangrove-lined estuaries along the coast form a living network that sustains both marine life and coastal communities.
Unfortunately, these ecosystems are under threat. Deforestation, pollution, coastal development, and climate change are weakening the links between mangroves, seagrasses, and reefs. That’s why integrated conservation – protecting not just one habitat, but the entire system – is so vital.
Strength in Connection
Reefs, seagrasses, and mangroves are not just neighbouring habitats – they’re parts of a living network, where each element supports the others. Just as we protect coral reefs for their beauty and biodiversity, we must also care for the quieter, murkier habitats that sustain them.
By understanding and protecting the connections between these ecosystems, we ensure that future generations of divers, locals, and marine life alike can continue to thrive in the waters of Dauin and beyond.
Cover photo by Imran Ahmed
