Super corals
Original Published Date: 
Wednesday, September 18, 2019

Full article issued by The University of Western Australia.

Super corals from extreme reefs can acclimatise to temperatures much lower than their natural environment but struggle to cope with their home reefs becoming hotter due to climate change, according to a global research team led by the ARC Centre of Excellence for Coral Reef Studies at The University of Western Australia.

Coral bleaching occurs as the result of abnormal environmental conditions, such as heightened sea temperatures that cause corals to expel tiny photosynthetic algae, called ‘zooxanthellae’. The loss of these colourful algae causes the corals to turn white, and ‘bleach’.  The researchers, led by Dr Verena Schoepf, conducted aquarium experiments to simulate translocating the naturally stress-resistant Acropora asperacorals from a hot, thermally variable reef in the Kimberley region to the much cooler and thermally stable Ningaloo Reef. Although initially displaying signs of cold stress, the corals were able to remain healthy and acclimatised rapidly to the cooler temperatures within a four month period.

Kimberley 'super corals' are among the toughest corals in the world, thriving despite the world’s largest tropical tides (a tidal range of more than 10 metres) and extreme temperature swings on a daily basis. Although they are well adapted to their extreme and hot environment under current conditions, climate change might overwhelm their stress tolerance. The findings have important implications surrounding the ability of such super corals to aid growth in areas where marine heatwaves and bleaching events have reduced coral abundance.

Photo credit: 

Image: super corals in the lab. Credit: UWA.