Bleached massive coral in Pulau Lang Tengah, Malaysia next to Coralku’s lead scientist, Sebastian.

Photo by K.L Chew (Coralku)

We experienced the warmest September this year in the according to the 174-year record by National Oceanic and Atmospheric Administration or NOAA. The oceans were also holding up record high temperatures for the sixth consecutive month. This confirms that 2023 is on track to be the hottest year on record.

Signatories to the Paris Agreement in 2015 agreed to halt global warming in this century ‘well below’ 2 °C compared to pre-industrial levels and ideally limiting it to 1.5 °C.

However, we were closer to that reality 2 months ago when the average global temperatures were 1.44°C higher than during the Industrial Revolution. The rational for the ‘well below’ 2°C target was to prevent irreversible damage from catastrophic climate disasters such as floods, hurricanes, heatwaves, and sea level rise.  

Even though experts say that one year surpassing the 1.5 degree target does not equate to the failure of the Paris Agreement due to the natural variability of global temperatures, but it gives us a hint to what could actually happen.

Climate related disasters in Malaysia

Malaysia is not spared from the effects of a warming planet. Paddy farmers in the state of Kedah have noticed the intense heat resulting in lower crop yields compared to a decade ago. Current projections suggest a 30.8% yield drop in the highest-yielding granaries as soon as 2030.

Meanwhile, residents of eight other states were faced with catastrophic floods in years 2021 and 2022.

In 2021, a total of 129,000 people were displaced due to floods compared to 24,000 in 2020. The following year, the flood and landslide victims increased to 156,000 according to the Internal Displacement Monitoring Centre (IDMC). The IDMC further recorded 354,000 climate-related internal displacements between 2016 and 2021 in Malaysia.

Besides floods and drought, 1,350km of Malaysia’s coastline are at risk by erosion caused by rising sea levels. This forces coastal communities such as fishermen or tourist operators to switch jobs, as they must live further away from coral reefs, while the warming of the oceans threatens fish stocks and reduces tourism potential of coastal habitats.

Effects of warming ocean temperatures

The ocean covers 70% of earth’s surface and is an excellent indicator of temperature changes. The oceans absorb 90% of heat, and the top few meters of the ocean store as much heat as the earth’s entire atmosphere.

Warming ocean temperatures is not good news for over 1 billion people who depend on healthy coral reefs for food, income, and coastal protection. Earlier this year, Asia experienced its second hottest September on record, and average global ocean surface temperatures were above average by +1.03°C.

 As ecosystems, coral reefs depend on the relationship between the coral animal and it’s symbiotic algae partner. This mutually beneficial relationship enables coral reefs to build vibrant, colourful, and highly productive ecosystems.

Corals also secrete layers of calcium carbonate that builds the reef structures that protects coastal areas from the impacts of large waves. When exposed to higher than usual temperatures, the living algae organisms gets expelled from the calcium carbonate skeleton and leaves the coral individual. This process turns the once colourful reef into a landscape of white skeleton structures, hence the term coral bleaching.

This can affect the entire coral reef ecosystem and trickle down to an ecosystem collapse that will affect at least 25% of ocean biodiversity and eventually affecting food security and our livelihoods.

The before and after of coral bleaching in Pulau Lang Tengah, Malaysia. Photo & edit by Coralku

This year, Central America, North America and the Caribbean witnessed mass bleaching events due to extreme heat stress levels that were never recorded at that scale before, experts say.

An unprecedented mass coral bleaching is expected in 2024 due to the combination of El Niño - a naturally occurring climate pattern that results in the warming of the ocean’s surface temperatures - and record breaking ocean surface temperatures due to climate change.

There is a 98% likelihood that at least one of next five years, and the five-year period as a whole, will be warmest on record, beating the record set in 2016 when there was an exceptionally strong El Niño. What would that mean for our coral reefs for the next 5 years?

Restoring corals for the future

Depending on severity and frequency of the heatwaves, corals can recover from bleaching events. But what if we could pick corals that are resilient than others for restoration?

Restoring corals is a labour intensive and intellectually challenging feat, especially in the uncharted territory arising from the climate crisis. In addition to that, the ecological success of restoration efforts is not commonly compared to the total cost and investments coral restoration requires.

So how do we plan our coral restoration efforts to ensure it is ecologically and economically effective and scalable, while keeping in mind the threat of ocean warming?

Leading this quest is a collaborative effort called Project ASSIST.  This project consists of non-profit organisations, Coralku, the Malaysian Society of Marine Sciences, and Triton Society, as well as academic institutions like University of Konstanz and Universiti Malaya, while local tourism stakeholder Summer Bay Resort is playing a central role as well. The project started in Pulau Lang Tengah (Malaysia) in September 2023 and will continue until late 2026.

The aim of the project is to create a science-based framework to determine the best way to select corals for restoration with the climate crisis in mind. In the first phase, large-scale heat stress tests were conducted to test the resilience of corals to extreme heat stress, similar to what corals experience during actual coral bleaching events. This will help filter out coral individuals that have better capabilities to (possibly) survive extreme marine heatwaves and ocean warming.

Even though surviving future heatwaves is crucial for successful coral restoration, corals selected for restoration must still ‘perform’ at the highest possible level. This means that planted corals must grow and reproduce at high rates, to ensure this practice is sustainable in the long-term.

Experimental set up for Project ASSIST. Photo by Joseph Henry (Triton Society)

In phase 2, Project ASSIST will use these “Super Corals” (i.e., corals with superior heat stress resilience) to build Malaysia’s largest coral nursery site. The scientific team plans to monitor the performance of these corals until they reach an appropriate size to be planted out on the reef.

Then, each coral outplant will be monitored and analysed to determine whether other fitness factors, such as growth rates, were comprised due to the higher heat stress resilience.

These different fitness factors, as well as the cost of running these tests, will help answer questions to better strategize a proactive coral reef restoration and management plan that can be used by practitioners in the region, or even globally.

The warming temperatures and the research that is being conducted are in a race against time. While efforts like these are meant to be applauded, it should not distract us from larger actions that must be taken to reduce greenhouse gas emissions. Negotiations and deals happening at global summits such as the Conference of Parties or COP28, need to move faster and result in bigger actions than ever before. We have waited nearly 3 decades to witness real action from negotiations at the global climate summit.