As global temperatures reach record highs, coral reefs face unprecedented challenges. A new research paper published in Proceedings of the Royal Society B: Biological Sciences has shed light on a glimmer of hope for coral survival amidst the warming oceans. The study shows that certain corals partnered with Durusdinium glynnii algae can thrive even in extreme heat, making them more resilient to climate change.

Coral reefs are essential ecosystems that support biodiversity, protect coastlines from storms, and contribute significantly to local economies through tourism and fisheries. However, since the 1950s, nearly half of all coral has died due to rising temperatures, leading to coral bleaching and eventual death. The situation worsened in 2023, becoming one of the hottest years on record, with an El Niño event further threatening the eastern Pacific region’s corals.

Researchers focused on antler coral, also known as cauliflower coral, for their study. This coral species can form partnerships with two different types of algae: one more susceptible to bleaching and one more resistant. The team collected samples and data from Gulf of California reefs off the coast of Baja California from 2004 to 2009, assessing the health and physiology of corals when paired with each type of algae.

Surprisingly, the study found that corals hosting heat-resistant D. glynnii algae showed similar growth rates to those with susceptible algae and comparable fertility rates. When exposed to a simulated heat wave in aquarium tanks, corals with the more thermally tolerant algae were unaffected, showing no decline in energy production and even exhibiting faster growth.

The findings are promising, offering a glimmer of hope for coral survival in the face of climate change. Scientists hope to use this knowledge to find and engineer “super corals” that can withstand rising temperatures. By understanding the dynamics between corals and heat-resistant algae, researchers aim to bolster the resilience of coral reefs, which play a critical role in the health of our oceans and planet.

References

• Turner, V. S. (2023, July 18). This pacific coral can withstand warming waters with the help of algae. Smithsonian Magazine; Smithsonian Magazine. https://www.smithsonianmag.com/science-nature/at-least-one-species-of-pacific-coral-may-thrive-in-warmer-waters-180982561/
• Turnham, K. E., Aschaffenburg, M. D., Pettay, D. T., Paz-García, D. A., Reyes-Bonilla, H., Pinzón, J., Timmins, E., Smith, R. T., McGinley, M. P., Warner, M. E., & LaJeunesse, T. C. (2023). High physiological function for corals with thermally tolerant, host-adapted symbionts. Proceedings of the Royal Society B: Biological Sciences, 290(2003), 20231021. https://doi.org/10.1098/rspb.2023.1021