Maldives coral reefs show signs of resilience and recovery

Corals reefs in the Maldives are showing signs of resilience, adaptation and recovery from the effects of climate change, an annual survey has found.

The survey was conducted in a 250km area in the central atolls by Biosphere Expeditions, Marine Conservation Society, Reef Check Maldives and local NGO Save the Beach, according to a press statement released on Tuesday. It was the ninth survey of its kind since 2010.

“We were devastated in 2016 when a global warming event killed off large swathes of the reefs. The reefs showed little recovery in 2017 and 2018, and we expected more bad news in 2019,” said Dr Jean-Luc Solandt, the expedition’s lead scientist.

The team found many baby corals less than one year old and young corals between one and three years old as well as various coral species growing at sites expected to be dead or dying.

“It was surprising and encouraging to see a greater diversity of corals ‘pushing through’ from the dead layer below. It seems nature is fighting back with a coral diversity explosion. We have seen resilience (of corals that are resistant to bleaching), adaptability (some reefs have other species coming through) and recovery (baby corals are almost everywhere) this year,” explained Solandt, who also recently authored a scientific paper on the health of Maldivian reefs.

Rising sea temperatures, ocean acidification, pollution and overexploitation have been killing coral reefs across the world.

Despite the positive findings, Solandt noted that many reefs have been badly affected and some have died, warning that a further spike in ocean temperature would kill off new corals.

“Also, some small corals that had settled on the reef in the last year, which we thought were resistant to bleaching, were now bleached, but the larger ones seem OK. Finally, the background temperature is still ‘hot’ at the bleaching threshold of 30 degrees Celsius in very shallow water,” he added.

Hussein Zahir, head of LaMer, one of the expedition’s local partner organisations, observed that the change in government last November was cause for optimism as the new administration has acknowledged “the close link between oceans, climate change and the wellbeing of communities.” He also noted the establishment of a National Marine Research Institute, the declaration of marine protected areas, and a pledge to ring-fence income from the green tax levied on tourists to spend exclusively on environment protection. 

Rasdhoo Madivaru, which was recently declared a protected area, was found by the survey to be resilient to bleaching and home to sharks, manta rays, turtles and Napoleon wrasse.

“Our expeditions have highlighted this site for the past nine years, as being of extraordinary biodiversity value,” said Solandt.

Dr. Matthias Hammer, Executive Director of Biosphere Expeditions, commended the work of professional and citizen scientists as well as the local and international partners involved in the annual expeditions for their role in designating protected areas. 

“This is yet another feather in our cap of achievements through citizen science and community-based conservation, and an important stepping stone for tackling the adverse effects of climate change in the Maldives. It shows how ordinary people and grassroots action can make a difference,” he said.

Local groups Save the Beach and Reef Check plan to carry out further surveys and “also train more local divers to survey their own reefs in the future, and set up more community-based reef conservation efforts,” said Hassan Ahmed ‘Beybe.’

Coral reefs form the bedrock of Maldivian islands. Bleaching occurs when warmer water stresses the coral and disrupts the symbiotic relationship with a micro-alga called zooxanthellae, causing the coral to expel the food source and turn white. Bleached coral can starve and die.  

In May, the Maldives was classified at the ‘warning’ alert level by a satellite monitoring programme of the United States National Oceanic and Atmospheric Administration. The local Marine Research Centre at the time advised the government to suspend projects that affect the health of reef ecosystems, such as dredging, land reclamation and beach nourishment projects.

While coral reefs in the Maldives recovered relatively quickly after previous bleaching events, the MRC said stressors that damage reefs could slow the rate of regeneration.