One of the world’s most prominent coral researchers recently offered his insight into the resilience of reefs and their most threatened corals at the invitation of the Association of Reef Keepers BVI.
He also warned about the potential next big killer of Caribbean reefs.
Dr. Bryan Wilson is a researcher with the University of Oxford’s Department of Zoology, and his focus is a species he believes to be the rarest coral in the world: Ctenella chagius.
During a July 13 lecture at Bamboushay Lounge, he described how his research into this species of brain coral — which previously was thought to be extinct — has helped shed light on the challenges corals face and how they survive threats like the peyssonnelid algal crust that has now made its way to Virgin Islands waters.
While he made a brief stop in this territory and the United States VI to research the algae, most of his work over the last four years has been based in South Asia. There, he has studied the Ctenella chagius brain coral at the Chagos Archipelago, a massive protected area located south of the Maldives. The largely uninhabited islands are home to the largest coral atoll on the planet, with some 350 known species of coral.
“When nature is left undisturbed, it thrives beautifully,” said Dr. Wilson, who has studied the Chagos reefs through assistance from the Bertarelli Program in Marine Science, a collaborative project bringing together scientists to study the Indian Ocean. “This is why this reef area is such a special place to be, because it’s one of the only places on the planet where we can study the effects of climate change on coral reefs without anything else interfering.”
Reef health
Dr. Wilson noted that the terrestrial environment around reefs plays a significant role in their health.
Strong shoreline vegetation provides habitat for robust bird populations in the area that in turn fertilise the reefs.
“What we find in the Chagos Archipelago is that because of this fertiliser that comes from these incredible seabird populations, the corals are bigger than other corals around the world, and they recover far faster after bleaching events,” he said.
Even in this remote, protected paradise, however, marine ecosystems face human threats. Since the first major coral bleaching event in 1998, instances of bleaching have occurred more and more frequently, Dr. Wilson said.
The Chagos Archipelago reefs are more resilient to the phenomenon than reefs in more populated areas, but the microorganisms that make up corals nevertheless die if water temperatures remain too high for more than a few weeks.
“The beauty of the archipelago and the fact that it’s so far removed from the human race is that the corals here recover almost four times faster than any other coral region on the planet,” he said. “This is because they’ve got nothing else to deal with. They’ve got no fishing. They’ve got no anchoring. They’ve got no clumsy swimmers. They’ve got no pollution — none of the other things that affect other reef regions in the world. So when these corals do die out, they also recover very, very quickly. Again, this is the reason marine protected areas are so, so important.”
Despite protections, Dr. Wilson said the area still faces threats including illegal fishing. Plastics also float among the waves in staggering quantities, even where people haven’t stepped foot in decades, he explained.
In the VI
Here in the Caribbean, corals face similar pollution threats, but also a new threat of an algae that thrives in hot, acidic waters that have become more common with the progression of climate change.
“The reason I’m here is to see whether it’s in the BVI as well,” he said of the algae known as peyssonnelid algal crust. “The bad news is, it is. Our worry is that, essentially, this is the next big thing that’s going to kill the Caribbean reefs.”
One potential saviour is the black sea urchin, which eats the algae and has been shown to create space for baby corals to thrive.
Despite the challenges, Dr. Wilson shared hope for the future of threatened corals. Those hopes were strengthened, he said, after he rediscovered the rare Ctenella chagius brain coral in the Chagos Islands in 2019.
“I found six colonies on this one expedition,” he said of his trip to the archipelago that year. “It gave us this hope that maybe it wasn’t extinct, and there was a hope to try and save it.”
He made several return visits, going on to discover what he believes to be the “last great stand” of these corals in the western Indian Ocean. He collected DNA samples, hoping to discover more about how corals can survive.
“Every time I go back out to the archipelago, I’m desperately worried that in the year all these corals will have died, and I’ll be coming back to a dead reef,” he said.
A pleasant surprise awaited him on his most recent trip, though, as his team documented 62 specimens of the rare coral, including one that could be a century old.
“Most beautifully of all, I found a baby, probably about six months old,” he said. “That’s an incredible thing, because it means that these corals are breeding, and the next generation is still there.”
Rescue efforts
He acknowledged that some people may question why it is worth trying to save such highly endangered corals.
“For me, if I can save the world’s rarest coral in one of the most difficult-to-get-to parts of the world, that means all the other corals that are lining up behind it to die out have that slightly better chance of being saved,” he said, adding, “One thing that gives me hope is that we’ve never been more aware, as a society, of the damage that we’re doing to the planet.”
Attendees asked how they could support VI reefs, and Dr. Wilson said one of the best ways is working to reduce one’s carbon footprint.
ARK Managing Director Dr. Shannon Gore urged residents to report reef threats — particularly of the golden-coloured peyssonnelid algal crust — by emailing ARK at info@bviark.org.
“The more information that we can collect, the better,” she said.
Dr. Gore said the organisation hopes to continue working with Dr. Wilson to deepen its understanding the territory’s coral reefs.