International study analyzed over 7,000 reef fish species across 87 islands and archipelagos worldwide
A study analyzing islands such as Fernando de Noronha, Trindade, and the São Pedro and São Paulo Archipelago revealed that the biodiversity potential of these ecosystems has been underestimated. In Brazil, some species are found only on oceanic islands, though a number of them are shared among a few islands. In this context, the research showed that even when animals were present on just two islands, they were not classified as endemic.”
“When we conducted this study and classified a large number of species, we found that about 40% of all species are exclusive to oceanic islands. In reality, most are shared – often between just two islands. We then began quantifying other locations considered icons of endemism, such as Hawaii and Easter Island, and saw that many species previously thought to be endemic were also shared with other islands. When we reviewed the literature, we noticed that the high endemism rates reported in the Pacific often included shared species, whereas our researchers here were more conservative and did not count them,” explains Professor Hudson Pinheiro, of USP’s Graduate Program in Zoology and a researcher at the Center for Marine Biology (CEBIMar).
Endemic species are those found exclusively in a specific region. Along Brazil’s coast, for example, 25% of fish species are exclusive to the country. Pinheiro adds: “On our oceanic islands, about 10% of Brazil’s fish fauna is found exclusively on those islands and not along the mainland coast. It’s a very high level of biodiversity – a very high proportion of exclusive species.”
In the case of oceanic islands, long-term isolation can lead to adaptation and species differentiation. The professor explains that in the studied archipelagos, endemism is key to understanding evolutionary history and the processes behind species origins in marine environments.
A dive into biodiversity
In addition to the work of research groups, the study involved compiling data from islands and marine environments around the world. The professor also highlights marine expeditions to Brazil’s oceanic islands, funded by Fapesp, CNPq, and other organizations such as Boticário Foundation.
“At the Center for Marine Biology, a specialized USP institute, we are launching a Technical and Scientific Diving Center – the only one of its kind in Brazil – which allows us to conduct technical dives and train researchers. With the equipment we have, we can perform very long dives, lasting more than six hours and reaching depths of up to 150 meters,” says Pinheiro. He explains that these dives have already led to the discovery of new species and to a deeper understanding of Brazilian biodiversity.
Pinheiro emphasizes that the processes of island occupation and colonization have already led to the extinction of some marine species, and that with the advance of climate change, isolated oceanic species are especially vulnerable because they cannot migrate to other areas. He cites the damselfish, which once inhabited certain islands in the Galápagos, as an example.
The professor also explains that recognizing the uniqueness of these species makes it possible to turn such locations into living laboratories and priority areas for conservation. “Models indicate that many species tend to migrate southward as global and ocean warming progress. But on oceanic islands, that is not the case – species have nowhere to go, so many of them are at risk of extinction,” he warns.
English version: Nexus Traduções, edited by Denis Pacheco
