New Delhi: A new study has revealed that Coral reefs are likely adjusted to higher ocean temperatures which could reduce future bleaching impacts of climate change,
The study led by Newcastle University that focused on the Pacific island nation of Palau has demonstrated that coral reef heat tolerance has historically increased.
The findings showed how, if global carbon emissions are reduced, this capacity could lessen the effects of bleaching in the future.
Published in the journal, Nature Communications, the results affirm the scientific consensus that the severity of future coral bleaching depends on carbon emissions reductions.
“If coral thermal tolerance continues to rise throughout the 21st century at the most-likely historic rate, significant reductions in bleaching impacts are possible” the study said.
Study lead author, Liam Lachs, is part of Newcastle University’s Coralassist lab said “Our study indicates the presence of an ecological resilience to climate change, yet also highlights the need to fulfill Paris Agreement commitments to effectively preserve coral reefs,”
Lachs said“We quantified a natural increase in coral thermal tolerance over decadal time scales which can be directly compared to the rate of ocean warming.
It said the High-frequency bleaching can be fully mitigated at some reefs under low to-middle emissions scenarios where, for example, the Paris Agreement commitments are fulfilled.
“However, such bleaching impacts are unavoidable under high emissions scenarios where society continues to rely on fossil-fuelled development” it mentioned.
“While our work offers a glimmer of hope, it also emphasizes the need for continued action on reducing carbon emissions to mitigate climate change and secure a future for these vital ecosystems”he added.
Study co-author, Dr James Guest, of Newcastle University’s School of Natural and Environmental Sciences said that “We know that coral reefs can increase their overall thermal tolerance over time by acclimatisation, genetic adaptation or shifts in community structure, however we know very little about the rates at which this is occurring.
“The results provide some hope that reefs can keep up with increasing temperatures, but only if strong action is taken on climate change” the study said.
Prof. Donner said. “That resilience, however, can also come at a cost, in terms of reduced reef diversity and growth. Without sharp cuts in greenhouse gas emissions over the next two to three decades, the reefs in the Pacific won’t provide the resources and protection from waves that Pacific peoples have depended upon for centuries.”
Coral reefs are facing unprecedented declines due to marine heatwaves and resulting mass coral bleaching and mortality events. To persist under climate change, coral communities need to endure progressively more intense and frequent marine heatwaves.
The study also tested different levels of global action to mitigate climate change and reduce carbon emissions, investigating four emissions scenarios and their impact on future coral bleaching projections.
The findings revealed that the thermal tolerance of corals in Palau has likely increased at a rate of 0.1 °C per decade since the late 1980s.
This increase suggests that natural mechanisms, such as genetic adaptation or acclimatization of corals or their symbiotic microalgae, could have contributed to the enhancement of coral thermal tolerance”it said.
