Divers checking on reefs. — Photo courtesy of Nadhirah/Reef Check Malaysia
MOST people know that healthy coral reefs are vital for marine life. But few know who actually checks on their condition – or how the health of a reef is measured.
A recent six-day EcoDiver Training course in Kudat, held from Oct 6-11 by Sabah Parks and Reef Check Malaysia, offered a closer look at what it takes to monitor the state of Sabah’s reefs.
The training took place at the Tunku Abdul Rahman Marine Park, where participants learned the same techniques used by scientists around the world.
According to Reef Check Malaysia’s 2024 Annual Survey Report, reef surveys follow a simple but powerful idea – using “indicator species”. These are common marine organisms that are easy to recognise and that reveal how healthy a coral reef is.
By observing these species and recording what they see, divers can collect data that scientists use to spot changes in reef conditions over time.
The standardised Reef Check method means results can be compared across different islands, regions or even countries.
The goal is to detect early warning signs – bleaching, damage or imbalance – before the reef suffers lasting harm.
When changes are spotted early, marine managers can act quickly, launching studies or conservation efforts to help the ecosystem recover.
So what exactly happens during a reef check?
Divers swim along a 100m line, counting marine life within specific 20m sections. They record four main types of data: fish, invertebrates, substrate (the seabed surface) and signs of impact or damage.
Each group of creatures tells a different story about reef health.
Fish indicators include species like Butterflyfish, Snapper, Parrotfish and Grouper, which are either targeted by fishermen or play important ecological roles.
Invertebrates such as Sea Cucumbers, Lobsters, Urchins and Giant Clams can show whether reefs are overharvested or imbalanced.
Substrates – the materials covering the seabed, from coral and rock to sand and algae – give clues about the reef’s structure and the effects of sedimentation or pollution.
Finally, divers record signs of stress such as bleaching, anchor damage, destructive fishing, coral-eating pests like the Crown-of-Thorns starfish, and even trash.
Sabah Parks director Datuk Dr Maklarin Lakim said four of the agency’s officers joined the course, along with 14 staff from tour operators and local communities.
Jamie Ng, another Sabah Parks officer, added that EcoDiver certification allows the agency to conduct its own in-house training in future.
Reef Check’s approach bridges science and community action, turning ordinary divers into the eyes and ears of the ocean.
