Reef revival: Fiji’s corals bouncing back after ruinous cyclone
In the immediate aftermath of the strongest cyclone to ever make landfall in the southern hemisphere, reefs across the Namena reserve and Vatu-i-Ra conservation park off Fiji were reduced to rubble.
Tropical Cyclone Winston struck Fiji on 20 February 2016, causing devastation on land and underwater. Winds of up to 280km/h claimed 44 lives, leaving more than 40,000 homes damaged or destroyed, and storm surges smashed reefs in their path. Winston caused US$1.4bn in damage, the most destructive cyclone ever in the Pacific.
But four years on, to the delight of scientists, the coral reefs of the Fijian archipelago are vibrantly resurgent and once again teeming with fish and colour.
A recent dive expedition led by the Wildlife Conservation Society found the coral had recovered beyond scientists’ expectations.
“I was surprised at how quick the recovery has been, especially at the Namena reserve,” the director of the Wildlife Conservation Society Fiji, Sangeeta Mangubhai, told the Guardian.
“The fast recovery likely reflects these reefs have good natural recruitment and they are well managed. Coral reefs that were healthier [before a destructive event like a cyclone] are expected to recover a lot faster.”
Besides the abundance of young coral colonies in both protected areas, the team found fish had returned in significant numbers across all areas, even to parts of reefs where corals had not yet been replenished.
Tropical coral reefs provide essential habitat for many fish species, serve as spawning and nursery grounds for commercially important fish, and recycle nutrients in otherwise nutrient-poor tropical oceans.
WCS Melanesia’s regional director, Dr Stacy Jupiter, said the organisation had worked with the local iTaukei communities, who hold customary fishing rights over the Vatu-i-Ra and Namena, to establish reef management measures, including large “no-take areas” covering significant sections of highly biodiverse reef.
The Namena reserve and Vatu-i-Ra conservation park collectively cover nearly 200 sq km and encompass various marine ecosystems, including shallow reefs, deep water passages and small islands.
Since the 2016 cyclone, WCS Fiji has conducted three dive surveys – after one month, six months and then, in December 2020, more than four years after the storm – to record the immediate destruction and chronicle the reef’s recovery.
“WCS Fiji is interested in understanding how highly destructive cyclones such as Cyclone Winston and Cyclone Yasa [both category 5] impact coral reefs, and how quickly these reefs recover,” Mangubhai said.
While the Fijian findings are promising – vital in a country where most people, directly or indirectly, rely on fish and are dependent on the ecosystem created by healthy reefs – around the world coral reefs are in dangerous decline.
The climate crisis is projected to result in more intense tropical cyclones and cause warmer and more acidic oceans, potentially killing corals and inhibiting their growth.
Reef experts argue greater international cooperation is required to reverse the trend of decline of coral ecosystems, while local management, such as continued and enforced protection of areas, is a key tool in maintaining healthy reefs.
“Healthy reefs are important given how dependent coastal communities are on coral reefs for food, livelihoods and cultural practice,” Mangubhai said. “They are also critical for coastal protection against future storms.”