Bleaching threatens Malaysia’s coral reefs, report finds

By Jheruleene Anne Ramos

Malaysia’s coral reefs are facing severe stress following last year’s global coral bleaching event, according to a new report that underscores their growing vulnerability to climate-related threats.

The 2024 Malaysia Coral Bleaching Impact Report, released by Coralku and Reef Check Malaysia, found that 50.7 percent of surveyed reefs in Peninsular Malaysia and Sabah experienced bleaching, with an average mortality rate of 34.1 percent, as cited by the New Straits Times. 

Among the hardest-hit areas was the Terengganu archipelago, which recorded an average coral death rate of 44.2 percent.

The findings are based on monitoring conducted across 24 sites in northeastern and southeastern Peninsular Malaysia, as well as eastern and western Sabah.

Coral bleaching occurs when environmental stress – such as increased temperature, light, or nutrient changes – causes corals to expel their symbiotic algae, turning them white and potentially leading to death if high temperatures persist.

Complex corals hit the hardest as reefs near ‘tipping point’ 

Coralku founder and lead author Sebastian Szereday said the 2024 bleaching events disproportionately impacted complex coral species essential to reef structure and fish habitats, with their loss diminishing both ecological integrity and economic value for tourism and fisheries.

“This threatens not only marine ecosystems, but also the aesthetic and economic value of reefs, which are vital to local tourism and fisheries,” he said. 

Currently, six archipelagos within Malaysia’s marine parks are valued at MYR8.7 million, based on data from the Department of Fisheries Malaysia.

He also said that the results of the study highlight that Malaysia’s coral reefs are at a “tipping point,” which means that bleaching can negatively impact biodiversity and communities in the future if the matter remains unresolved. 

Coral reefs support thousands of marine animals that heavily rely on them for survival such as fish, crabs, shrimp and jellyfish, while it also serves as a natural barrier to absorb the force of waves, keeping coastal communities safe. 

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A long-standing threat  

Although this year’s bleaching is severe, coral bleaching has been a recurring problem affecting Malaysian reefs for years.

According to The Star, the Fisheries Department reported that more than half of coral reefs in Malaysian waters were impacted by bleaching between April and June 2024. This was driven primarily by elevated sea surface temperatures.

Reefs surrounding marine islands such as Pulau Payar (Kedah), Pulau Perhentian, Pulau Redang, and Pulau Tenggol (Terengganu), as well as Pulau Tioman (Pahang) and Pulau Pemanggil (Johor), were particularly affected.

Dive operators, divers and environmental non-governmental organisations also said that the country is experiencing “mass bleaching”, which refers to the large-scale bleaching of multiple coral species over wide areas. 

Calls for improved monitoring, regulation and government action

Lee Li Keat, report co-author and a researcher at the National University of Singapore, called for expanded standardised bleaching monitoring protocols to identify heat-resilient coral species and sites.

“Understanding the biological mechanisms behind coral resilience can inform restoration strategies and guide new interventions to help corals survive future thermal stress,” he said. 

Meanwhile, Chen Sue Yee, Reef Check Malaysia science officer and co-lead author, emphasised the need for stronger enforcement of “no-take zones” and fishing regulations to prevent habitat destruction.

Chen also urged the state and federal governments to take necessary action to support the country’s reef resilience.

“It is vital to take action to support our weakened reefs.”

“Measures such as eliminating land-based pollution, including untreated sewage, industrial waste and agricultural run-off and mitigating coastal development impacts like sedimentation and physical reef damage must be prioritised,” she said. 

She also called for greater promotion of sustainable tourism to reduce direct harm to coral ecosystems and for improved local research capacity to raise public awareness about the ongoing crisis.

However, experts concluded that any long-term solution must ultimately address the root cause – climate change – by reducing greenhouse gas emissions and improving environmental protection.

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