BY KATIE - MYGREENPOD, 18 August '16

Over 60% of Maldives corals affected by climate change-related mass bleaching

Preliminary findings of a comprehensive scientific survey examining the impact of the climate change-related 2016 mass bleaching in the Maldives indicate that all reefs surveyed were affected by the event.

Approximately 60% of all coral colonies assessed – and up to 90% in some sites – were bleached.

Mass coral bleaching

Higher than average sea surface water temperatures, linked to an El Niño Southern Oscillation Event, have caused mass coral bleaching around the world in 2016.

The survey – conducted by the Maldives Marine Research Center (MRC) and the Environmental Protection Agency (EPA), in partnership with the International Union for Conservation of Nature (IUCN) – brought together coral reef and bleaching experts from 11 national and international institutions and universities to assess the impact of the mass bleaching on coral reefs in the Maldives.

‘Bleaching events are becoming more frequent and more severe due to global climate change.

‘Our survey was undertaken at the height of the 2016 event and preliminary findings of the extent of the bleaching are alarming, with initial coral mortality already observed. We are expecting this mortality to increase if bleached corals are unable to recover.’

DR AMEER ABDULLA
Research team leader and Senior Advisor to IUCN

The Maldives

The Maldives contains approximately 3% of global coral reefs and is one of the most vulnerable countries to climate change impacts given its mean land height of 1.5m.

Funded by the US Agency for International Development (USAID), the survey was undertaken in Alifu Alifu Atholhu (North Ari Atoll), a representative atoll of the Maldives.

It examined both inhabited and uninhabited coral reef islands in sheltered and exposed locations. The main purpose of the survey was to document the extent and severity of the bleaching in the Maldives, which occurred as a result of unusually high temperature exposure and local human stressors, using Alifu Alifu as a case study.

‘This survey was a key component of the Government´s Bleaching Response Plan. It has provided us with unique insight into the effects of this coral bleaching event, and helped us understand the implications of climate change for our nation. Understanding the pattern and impacts of bleaching in Maldives will help us guide local management of highly vulnerable sites.’

DR SHIHAM ADAM
Director general of the MRC

How bleaching occurs

Bleaching is the result of symbiotic algae living in coral tissues being expelled due to stress caused by extreme and sustained changes in temperature, light or nutrients.

This process causes coral to turn completely white and can occur at large spatial scales spanning entire reefs and countries. Bleached corals are at risk of death if conditions do not return to normal.

‘As part of our management guidance to local communities and resorts, we have emphasised the importance of reducing local stressors such as sedimentation, pollution and overfishing of herbivores.

‘Local management actions can build the resilience of coral reefs thus helping them to survive this national bleaching event.’

MR NAEEM IBRAHIM
Director general of the Environmental Protection Agency

Practices such as dredging, sand replenishment and fishing or purchasing of herbivorous fish such as parrotfish and surgeonfish – which are essential for reef recovery – are being strongly discouraged. Reef users are also being urged to minimise adverse impacts to corals during this sensitive and critical time.

A national response

To coordinate a national response to the phenomenon and provide guidance to reef users on how to manage the impact, the Maldives government has created the Maldives National Bleaching Task Force.

Led by the MRC, the Task Force includes the Environmental Protection Agency and is supported by IUCN. A national monitoring program has also been developed by MRC and IUCN to evaluate recovery of reefs across the country.

The program enables resort marine biologists, citizen scientists and divers across the Maldives to contribute data that will help reveal the national effects of the global bleaching event.

Reported data are currently being analysed in order to identify vulnerable and resilient reefs across the country that should be managed or protected.

Ocean and coral reef conservation will be among the issues highlighted in the IUCN World Conservation Congress 2016 taking place from 01-10 September in Hawai´i.

Click here for more on the IUCN and its research.