Atauro Island: Scientists Discover The Most Biodiverse Waters In The World

A small island, a short boat trip from Timor-Leste’s capital, Dili, appears to have the most biodiverse waters anywhere in the world. There is a push for the site to be protected with a view to developing an ecotourism industry for the country’s struggling economy.

Atauro Island sits just 24km north of Dili, is 23km long and is home to about 8,000 people. According to a new biological survey, it sits in waters that have more species of reef fish per site than any other place on the planet.

Examining 10 sites around the island, a Conservation International team, with 50 years of combined experience surveying thousands of reefs around the world, found an average of 253 reef fish species at each site. That surpassed the previous record for a reef in West Papua, which had an average of 216 species at each site.

Altogether, the researchers have counted a total of 642 species and saw a maximum of 314 at a single site. Among those were several species that were suspected to be entirely new as well as some that were very rare elsewhere.

The site is inside an area known as the Coral Triangle, which has the highest biodiversity of any marine environment in the world. But, despite that, the researchers were surprised by the record-breaking biodiversity at Atauro Island.

“My senior colleague Gerry Allen and I have done well over 10,000 dives between the two of us in the Coral Triangle region, so we are certainly used to high-diversity sites,” says Mark Erdmann from Conservation International. “But Atauro proved exceptionally rich.”

Erdmann says that three of the 10 sites had more than 300 species of fish – a figure touted as showing extraordinary biodiversity.

“We’ve used this survey technique for over a thousand sites in the Indian and Pacific oceans and the only sites we’ve ever surpassed 300 species are in the region between North Sulawesi and West Papua in northern Indonesia – an area we refer to as the bull’s-eye or epicentre of reef fish biodiversity.”

Michel Kulbicki, an expert in coral reef biodiversity at the Institut de Recherche pour le Développement says the researchers are world experts in doing these surveys.

“It is very likely that reefs in Timor could hold very high diversities of reef fish and it is probable that they rank amongst the richest ones,” he says.

“Discovering new species in these waters is not surprising. We estimate that at least 10% of reef fish species are still undescribed, and a large number of these undescribed species are probably found in the Coral Triangle,” Kulbicki says.

But Erdmann says, despite the exceptional biodiversity, some of the reefs around Atauro are not in the best health.

“Some sites have stunning hard coral gardens and breathtaking vistas full of schools of reef fish, while other sites sadly show the scars of legacy blast fishing, as well as past crown-of-thorns starfish outbreaks.

“Moreover, large predatory fishes including groupers and sharks and the iconic Napoleon wrasse were all exceptionally rare – a clear sign of overfishing.”

Erdmann says that active protection of the reefs there “could pay significant dividends almost immediately”.

“Overall the reef resources on Atauro are still in pretty good shape – a well-organised conservation and fisheries management effort could quickly return these reefs to amazing condition.”

Accordingly, the researchers think the area should be made into a marine park.

Without question, our strong recommendation is that the whole of Atauro be designated a marine protected area, with active local management and enforcement,” Erdmann says.

He says that since the local communities rely on the reef for food, the area must be zoned for “multi-use” and allow fishing.

“However, we would recommend a ban on outside commercial fishing and moreover strongly urge the designation of a few key ‘no-take areas’ where no fishing or extraction of any kind is allowed, in order to allow reef fish stocks to recover and a strong breeding population to re-establish.”

Erdmann says if that is enforced it will improve the catch for local communities, since the no-take zones will “re-seed” the rest of the area.

“Diving on Atauro can be simply breathtaking,” he says. “Above water, the island strikes an impressive profile against the sky – heavily forested steep slopes teeming with birdlife, some of it endemic, and laid-back, friendly villages dotting the shoreline. Below water, much of the island has beautiful shallow reefs that plunge abruptly into the abyss and the clear waters are filled with colourful reef fish.”

Erdmann says Atauro Island would impress anyone that visits it and could contribute to a lucrative ecotourism market for Timor-Leste.