New research by colleagues and the author suggests that coral reefs in the Pacific have increased their resistance to high ocean temperatures, potentially improving their long-term futures if global action on reducing carbon emissions is taken. Corals are sensitive to even small increases in temperature, but their “thermal tolerance” can’t keep pace with ocean warming.
In normal conditions, corals live in symbiosis with microscopic algae housed within their tissue, which give them their beautiful colors and provide them with food through photosynthesis. However, when it’s too hot, the microalgae are expelled, leaving the corals stark white or bleached, which usually leads to death.
A study published in Nature Communications on the coral reefs of Palau, a nation of more than 300 small islands in the western Pacific Ocean, found that the thermal tolerance of coral communities in Palau has likely increased at 0.1°C/decade. This suggests these coral reefs have an innate capacity for climate resilience. More work is needed to pin down exactly what has happened, but various mechanisms could explain this, including species turnover, genetic adaptation, and individual acclimatization.
Read also : Some Pacific Coral Reefs Can Adapt To The Warming Ocean
The future of coral reefs depends on rapidly reducing carbon emissions, but if coral thermal tolerance can continue rising, bleaching could be avoided on some reefs or at least delayed. The study and others have identified reefs with some level of innate climate resilience, but securing a future for coral reefs still hinges on rapid climate action. Conservation measures, restoration efforts, and experimental interventions such as selective breeding to increase thermal tolerance might help corals persist into the future, but reducing carbon emissions is ultimately the only sure bet.
Source: upi.com
