Strong recovery for Malaysian coral
The El Niño effect this year has devastated coral reefs around the world, but the reefs of one island in Malaysia are fighting back.
Citizen scientists from Biosphere Expeditions have teamed up with Reef Check Malaysia to survey the coral reefs around the island of Tioman, off the east coast of peninsular Malaysia. The group was assessing the health of the reefs following the devastating rise in sea temperatures that happened in May this year. A temporary rise of 2 or 3 degrees Celcius, caused by this year’s El Niño event, has been causing corals all around the tropics to do something called ‘bleaching’, which can lead to the death of corals and then entire reefs. A coral bleaches when it expels the symbiotic algae that usually live within it. These algae give the coral its colour, without these algae the transparent coral appears white (or bleached) as we see through the animal to its white calcium carbonate structure. Without the algae the animal also loses around 80% of its energy which is usually supplied by the algae photosynthesising sugars. This eventually leads to the death of the coral through starvation.
But the reefs around Tioman island have been taking algae back, and in the months since the reefs were 30 to 40% bleached, they have largely recovered, as the Biosphere Expeditions team has found. The team, comprising citizen scientists from all over the world, also found reefs that were almost back to pre-bleaching states and which were generally healthy. So for these reefs the danger of bleaching has passed for now, but the threats of overfishing and pollution are still there. Very few larger predator fish were found during the surveys, indicating that fishing is still happening, despite Tioman being a Marine Protected Area. The amounts of nutrient indicator algae growing on some of the reefs led the team’s scientist, Alvin Chelliah of Reef Check Malaysia, to speculate on the amount of sewage that may be ending up on the reefs from some of the island resorts. It is through working with the communities on the island, as Reef Check Malaysia does, that the threats to these reefs will be tackled sustainability can be secured.
Pictures from the expedition: