Research shows that certain coral species have heat tolerance abilities that could help with coral conservation, a significant finding as ocean temperatures continue to rise.
Earlier this year, the world experienced its fourth global coral bleaching event, and the Great Barrier Reef has faced five mass bleaching incidents since 2016. The good news is that as efforts to reduce global carbon emissions and combat climate change continue, researchers are actively exploring ways to support coral health.
The study, conducted by researchers from Southern Cross University and the Australian Institute of Marine Science, focused on the tabular coral, Acropora hyacinthus. This type of coral is important for the reef but is also very sensitive to heat.
Scientists measured the heat tolerance of over 500 coral colonies across 17 reefs and found that some corals were able to keep up to 95 per cent of their colour when exposed to high temperatures, while others lost all their pigment and became completely bleached.
The coral’s colour comes from algae living inside it, which also provide most of its nutrition. When water temperatures rise too high for too long, corals expel these algae, causing it to bleach and starve. Hence, the study tested how much pigment, and therefore algae remained in the corals under heat stress.
Impressively, 12 of the 17 reefs studied contained colonies that showed strong heat resistance – indicating these resilient corals could play a critical role in the reef's future.
The study also found that corals in the northern Great Barrier Reef can handle higher temperatures but are already close to their limits, while those in the southern region can tolerate more warming above their local temperatures.
Discoveries like these are encouraging for coral adaptation and restoration efforts. By selectively breeding heat-tolerant corals, scientists are hoping to create offspring better suited to warmer waters. Selective breeding trials are currently in progress, using the most heat-tolerant corals discovered in the study.
While reducing greenhouse gas emissions remains crucial, interventions like selective breeding could help with the survival of coral reefs facing climate change, offering hope for their future before it’s too late.
By Ashmeeta Subra October 10th, 2024
Source: Planet Ark
