Beyond bleaching: Human activities threaten coral survival

SHAH ALAM - While mass coral bleaching is not caused by poor diving practices, such practices can significantly damage coral reefs.

Coralku Conservation, a coral restoration and conservation organisation, to support coral reef restoration projects said many coral species took years to grow to 50cm.

It said a single careless diver could destroy decades of coral growth.

This was exacerbated in popular diving spots in Malaysia, such as the Redang, Perhentian and Tioman Islands, where some reefs experienced the impact of 50 to 100 divers per day, or even more during peak seasons, putting immense stress on the coral ecosystems.

"For instance, we frequently see corals being broken by divers, who accidently kick corals with their diving fins, or because some parts of their gear is dangling lose, or sometimes even because divers cannot maintain neutral buoyancy and simply crash into corals.

"Therefore, some other groups have called for avoiding certain reefs to avoid further stress. This makes sense in locations where too many divers are diving the reef each day," it said when contacted recently.

Coral bleaching can result from factors like water quality changes, pollution and disease.

However, Coralku Conservation stressed that the widespread bleaching observed in Malaysia and globally was mainly due to rising ocean temperatures beyond corals' tolerance.

While mass bleaching naturally occurred every 25-30 years, it said climate change has caused more frequent and prolonged marine heatwaves.

Greenhouse gases absorbed by the oceans were driving these heat waves and consistently rising ocean temperatures.

Coralku Conservation said the ocean off the east coast of Peninsular Malaysia has warmed by 0.5-0.6°C since the early 1980s.

Without significant climate action, tropical reefs could face severe decline, with up to 90 per cent potentially lost in the next 30 to 40 years.

They highlighted that public programmes and activities were available on Lang Tengah Island.

However, they stressed that without addressing climate change, the oceans will keep warming.

This ongoing heat made effective coral reef restoration difficult, as corals struggle to adapt to the rapid rise in ocean temperatures.

"On the other hand, there are also certain coral individuals which are more tolerant of heat stress and these corals possibly have better chances to survive the present and coming heatwaves.

"We have been doing research to identify such resilient corals since 2019 and our silver lining of this year’s bleaching event is that we are able to identify these corals during an actual heatwave and select these for coral restoration," it said.

It also recommended adopting good diving and snorkelling practices, participating in beach clean-ups and maintaining a sustainable lifestyle by supporting groups, companies and products that are less harmful to the environment.

Meanwhile, Reef Check Malaysia marine biologist and programme coordinator Alvin Chelliah said while irresponsible diving did not cause bleaching, it can add stress to already bleached corals

He also noted that such diving practices more frequently result in physical damage to reefs.

"There are many ways for divers to help protect corals. Most notably is to join activities and programmes organised by non-governmental organisations and government agencies.

Chelliah said cleanups, net removals, cot removals, reef monitoring all contributed to keeping reefs healthy.

He said the main threat from tourism was physical damage from direct contact (stepping and touching) with the reef.

He added that solid waste and litter were significant issues adding that tourism operators could exacerbate these problems through inadequate waste management, sewage treatment, wastewater disposal, oil and fuel leaks and construction activities.

He said overcrowding at popular tourist sites was also a concern.

Chelliah highlighted that there were effective guidelines for various tourism industries, such as the Asean Green Hotel Standard, which resorts and hotels in Malaysia should strive to meet.

He said Reef Check has been promoting this standard in Tioman for years and also advocated for the Green Fins approach for dive centres.

Developed by United Nations Environment Programme (UNEP), he said this approach aimed to mitigate the environmental impact of diving and snorkelling activities.