Coral reefs are predicted to decline under the pressure of global warming. However, a number of coral species can survive at seawater temperatures even higher than predicted for the tropics during the next century. How they survive, while most species cannot, is being investigated by researchers at the National Oceanography Centre, Southampton (NOCS) and New York University Abu Dhabi (NYUAD).
We tend to associate coral reefs with tropical seas of around 28 degrees, where even slight warming can have devastating effects on corals. But in the Arabian/Persian Gulf, corals survive seawater temperatures of up to 36 degrees Celsius every summer, heat levels that would kill corals elsewhere.
In their study, the NOCS team worked closely with NYUAD researchers to select and characterise model corals from the Arabian/Persian Gulf, which will facilitate future molecular-scale investigations into why they can tolerate heat stress.
"We have established successful laboratory cultures of Gulf corals," said Dr Jrg Wiedenmann, Head of the Coral Reef Laboratory and Senior Lecturer at University of Southampton Ocean and Earth Science, both of which are based at NOCS. "This will greatly accelerate the progress of unravelling the mechanisms that underlie their surprising heat resistance."
Reefs are made up of many species of coral, each of which have a mutually beneficial, or "symbiotic", relationship with algae living in their tissue. These algae supply vital nutrition to the host but are sensitive to environmental changes including increases in seawater temperature.
Even a temperature rise of just one degree Celsius can harm the symbiotic algae, which in turn can increase mortality in corals. The associated loss of symbiotic algae is known as "coral bleaching" because the white skeletons of the corals become visible through the tissue depleted from the algal pigments.
"In Gulf corals, both the coral host and the associat
|Contact: Catherine Beswick|
National Oceanography Centre, Southampton (UK)