By Thomás Banha
Lionfish (Pterois spp.) were first recorded in the western Atlantic in the 1980s and rapidly spread across the Caribbean, causing significant ecological impacts. Many years later, in 2014, it finally reached Brazil – but not in the way scientists had anticipated. A decade after the first sighting, we still do not fully understand their impact on local ecosystems or what the future holds.
THE ALIEN
Lionfish belong to the genus Pterois, which harbors a dozen valid species native to the Indo-Pacific. Due to their beauty, they have long been popular in the aquarium trade. Unfortunately, two species (P. miles and P. volitans) were introduced into the Atlantic, first recorded in Florida, USA, in 1985. Their popularity even extended to pop culture, with lionfish as part of the plot in a late-1990s comedy film starring Rob Schneider.
Over the years, the invasion progressed steadily southward, linked to releases by aquarists and the reproductive output of the established population, eventually reaching Trinidad and Tobago. At that point, it seemed inevitable that the species would soon reach Brazil. But when the invasion finally happened, it was not as expected. To understand it better, I talked to Dr. Osmar Luiz, a researcher at the Marine Science Program, Dept. of Biodiversity, Conservation and Attractions in Australia. He was the lead author of the first study discussing the perspectives for the lionfish invasion in the South Atlantic.
THE ARRIVAL
Scientists were already aware of the possibility of the arrival of lionfish in Brazil. “We watched the invasion unfold in real-time, like a reality show. It was obvious they would get here” points out Dr. Luiz. He and his colleagues identified Fernando de Noronha Archipelago and Rocas Atoll – the only atoll in the South Atlantic – as the most likely entry points for lionfish in Brazil, due to their strong oceanic connectivity with the Caribbean. However, things did not go as expected.
NOT AS EXPECTED
Despite ideal conditions for their arrival, lionfish remained absent from Brazilian waters for longer than anticipated. “We expected to find them much earlier since they had all the traits needed to cross the Amazon-Orinoco plume,” highlights Luiz. But no lionfish was recorded in the area for years. The authors hypothesized that the northward direction of the ocean currents on the Amazon coast could be delaying the invasion. However, in 2014, the species was finally observed in Brazil, but with a surprise twist: thousands of kilometers away from where they predicted. The first Brazilian record came from Arraial do Cabo, in southeastern Brazil.
Figure 1: A lionfish follows a diver, using the diver’s light to hunt for prey in Shaab El Erg, Egypt. Photo credit: Kris-Mikael Krister.
BUT HOW?
This unexpected discovery raised a key question: Was this individual lionfish originally from the Caribbean or the result of an aquarium release? Genetic analysis revealed that the specimen was closely related to Caribbean lionfish, rather than those from the Indo-Pacific (the source for lionfish in Brazil’s aquarium trade). This data led the authors to suggest that this individual, found approximately 5,500 km away from the Caribbean, was a product of natural larval dispersal.
HELLO AGAIN
Following this observation, a few years went by without further records. Then, in 2020 – six years later – new individuals were observed in the sites originally predicted by Luiz and his colleagues. One individual was collected by divers in the Fernando de Noronha Archipelago and two others were found in the Great Amazon Reef System, captured by fishers targeting the Southern red snapper (Lutjanus purpureus). After that, sightings piled up. Between 2020 and 2023, more than 350 individuals were collected. Now, we have clues that a population might be established in Fernando de Noronha. This raises a crucial question: What can be done?
EMPTYING THE OCEAN WITH A SPOON
The outlook is not promising. The main solution currently available is the manual removal of lionfish, a strategy that has proven largely ineffective to stop its expansion in the Caribbean. “Even if we manage the lionfish, it might not work, as we saw in the Caribbean. The expectation is that it will continue spreading southward in Brazil,” Luiz warns.
Lionfish observations are being tracked along the Brazilian coast (see here) and have already been recorded within a few marine protected areas. Their impacts on native species and ecosystems are well-documented in other regions, and they are now posing risks to humans in Brazil, with the first cases of lionfish envenomation reported in the wild. With a decade of invasion behind us, there is little left to be done, as the main management approaches have not been successful elsewhere. While we should continue to attempt to manage the lionfish population, it may be just a matter of time before they become yet another permanent resident of Brazilian reefs.
REFERENCES
Luiz OJ et al. (2013) Perspectives for the lionfish invasion in the South Atlantic: Are Brazilian reefs protected by the currents? Mar Ecol Prog Ser 485:1-7.
Luiz OJ et al. (2021) Multiple lionfish (Pterois spp.) new occurrences along the Brazilian coast confirm the invasion pathway into the Southwestern Atlantic. Biol Invasions 23:3013–3019.
Luiz, OJ (2023) Invasive lionfish have spread south from the Caribbean to Brazil, threatening ecosystems and livelihoods. Available at: https://theconversation.com/invasive-lionfish-have-spread-south-from-the-caribbean-to-brazil-threatening-ecosystems-and-livelihoods-199229
Schofield PJ (2010) Update on geographic spread of invasive lionfishes (Pterois volitans [Linnaeus, 1758] and P. miles [Bennett, 1828]) in the Western North Atlantic Ocean, Caribbean Sea and Gulf of Mexico. Aquat Invasions 5:S117–S122.
Reefbites 