New Microalgae May Help to Protect Reefs from Coral Bleaching
A colorless coral reef as a result from coral bleaching. Photo Credit: Milan Degrave, Unsplash.
Hearts pound fast, muscles tighten, breath quickens and blood pressure rises in response to stress the bodies of humans undergo. People experience these bodily changes in reaction to stressful environments; organisms experience something similar.
Organisms like coral reefs experience coral bleaching when environmental conditions such as temperature, light and nutrients change causing the coral reefs to turn fully white.
The whitening of these coral reefs is dangerous. The white color is caused when the ocean conditions are altered and in response to this, the symbiotic algae, mutually benefiting organisms, that live in the tissues of these reefs, that serve as their food, is released to cope with the warming of the oceans that makes them starve. As this algae is released, the vibrant color of the coral becomes flushed and becomes colorless. This morbid activity that happens to these reefs is not only harmful to themselves but to the ecosystem itself.
“The unfolding crisis in coral reefs will have profound environmental, economic, social, and cultural consequences for reef-dependent societies,” Tiffany H. Morrison, Professor of the Australian Research Council Centre of Excellence for Coral Reef Studies institute at James Cook University, and her team of researchers said in their paper published in One Earth.
“Reefs provide critical ecosystem services, such as fisheries, tourism, and shoreline protection, that are essential to the social and cultural fabric of maritime tropical communities,” Morrison and her team said in their paper.
To help prevent these coral bleaching events, Dr. Patrick Buerger, molecular and microbial ecologist at the University of Melbourne, and his team of researchers have developed a microalgae strain that provides heat protection for the coral reefs. “We evolved 10 clonal strains of a common coral microalgal endosymbiont at elevated temperatures,” said Buerger and his team of researchers in their paper published in Science Advances.
Buerger and his research team developed this microalgae strain, a marine vertebra more bearing to temperature change by adapting it to warming temperatures over a span of four years.
“Once the microalgae were reintroduced into coral larvae, the newly established coral-algal symbiosis was more heat-tolerant compared to the original one,” explained Buerger and his team.
The authors’ paper emphasized how globally corals are “suffering mass mortalities from marine heat waves” from the rising environmental stresses. Plants and organisms can adapt to a changing environment and overall climate, but when it changes at a rate that is faster than they can handle, issues arise.
Climate oscillations are a natural phenomenon where various weather patterns have short continuous changes; wind direction, air pressure and sea temperature are just a few of these.
Instances like the 2005 Caribbean coral bleaching event resulted in a loss of half of the coral, and the 2010 bleaching in the Florida reefs had fatal repercussions.
The rapid speed of climate change seems daunting and unpredictable; however, short-term, and long-term solutions are being sought out. Buerger and his team demonstrated that “coral stock with enhanced climate resilience can be developed through ex hospite laboratory evolution of their microalgal endosymbionts.”
Successfully, the researchers were able to exhibit how the microalgae and coral can communicate and build on the reef's resistance to heat.
“Further research is required to examine whether the enhanced heat tolerance of the laboratory-evolved strains is maintained in the field under long-term exposure to ambient temperature (i.e., outside the summer season),” said the authors.