Coral Reefs around the world are in decline, from the Great Barrier Reef to the Caribbean, where coral reef ecosystems are threatened by climate change and rising ocean temperatures. As a result, we have witnessed catastrophic, extreme heat events leaving enormous swathes of Australia’s Great Barrier Reef bleached and dead. The same is occurring in the Caribbean but fortunately not everywhere. Does Bermuda hold the key to Coral Reef Resilience?
A Unique Geographic Location
Bermuda is home to the world’s highest latitude coral reefs and although, its corals have displayed some minor bleaching it has never been extensive nor prolonged.
“We typically are reprieved from some of the big global issues around coral bleaching,” said Samantha de Putron, a marine biologist at the Bermuda Institute of Ocean Sciences (BIOS). “We go out and see some of the corals starting to go, and then typically, it’ll be two weeks and the temperatures naturally come down.” As reported by Jessica Leber in Oceans Deeply.
The health of Bermuda’s reefs has given BIOS’s researchers the opportunity to acquire a better understanding into the conditions that enable Bermuda’s coral reef resilience and the implications that this might have for more vulnerable reefs further south.
“Our coral cover has remained remarkably stable,” Putrom said. “That’s put us on the map, research-wise. Why are the corals here so apparently healthy compared to anywhere else?”
Extreme Sea Temperature Range
The only coral atoll in the Atlantic Ocean, Bermuda’s coral reefs exist as a result of the warm waters carried by the Gulf Stream and are noted for their hardiness. Bermuda’s corals exist despite extremes in annual ocean temperatures that can drop as low as 61F (16C) in the winter or rise as high as 86F (30C) degrees over the summer. A temperature range that would normally doom corals growing in more tropical waters. This leads researchers to believe that Bermuda’s coral reef resilience is related to how well its corals have adapted over time to a wider range of temperatures and are therefore more resilient to climate change events.
Studying Coral Reef Resilience in the Lab
“Fifteen degrees Celsius throughout the year is a lot of fluctuation. A lot of the corals in the central Caribbean are much more sensitive,” said reef ecologist Gretchen Goodbody-Gringley who is working with Putron to determine if the temperature range of coral can be expanded by subjecting the corals to controlled but increasingly warmer water temperatures. In other words can corals “learn” to adjust to a warmer environment? So far indications are hopeful but also indicate how much remains to be learned.
Positive Possibilities With Limits
Success in Bermuda has limits because its reefs are home to less than half of the species that are threatened in the Caribbean. Especially absent from Bermuda’s reefs are branching corals like elkhorn and staghorn that are vital within the tropical coral reef ecosystem but unfortunately, have largely been wiped out in the waters of the Caribbean and Florida due to climate change. (photo – Stacey Peltier)
“One theory is that…the community that we have here may reflect what the broader Caribbean might look like in the future,” said Goodbody-Gringley. For someone who began diving at 15, on then-healthy reefs in Florida, “That would be a loss.”
Blue Ocean recently reported on a similar case of coral reef resilience in its article on the coral reefs in the northern waters of the Red Sea, read more in: Can Coral Find Refuge In The Red Sea??
By Robert Frerck, Blue Ocean Network
See These Related Blue Ocean Articles:
Reef Life Restoration Teams with Environmental Moorings to Save Coral from Anchors, Rebuild Caribbean Reefs
How To Get More Ocean-Hearted Intel Delivered To Your Inbox!
We believe ocean lovers can change the world. If you care about the health of the ocean and want to do something about it, then connect with the Blue Ocean tribe: Our growing community of ocean change-makers is turning ocean lovers into ocean leaders. It starts with you. Join us!