In their slow and steady march towards Atlantic reef dominance, the invasive lionfish Pterois volitans has at last crossed the final hurdle and been found in the reefs of Southeastern Brazil. To do so required it to traverse some inhospitable terrain, namely the effluent plumes of the Orinoco and Amazon Rivers. These sediment-rich waters are hostile to coral growth, and have resulted in a particularly endemic fauna on Brazil’s reefs, which is now imperiled by this new introduction.
A pair of specimens were reported by recreational divers along the rocky shores of Arraial de Cabo in May of last year. Genetic study revealed these to match their Caribbean counterparts, indicating that this was not a separate aquarium release. Presumably, these drifted south as pelagic larvae, but how they did so is not entirely clear. The northern coast of South America is dominated by the northerly-flowing North Brazil Current. Adults would likewise find it difficult to traverse the immense river outflowings of the region. So, whither the lionfish?
However the lionfish got to Brazil, it is almost certainly there to stay, and there is even greater cause for concern than in the Caribbean. The isolation and endemism of Brazilian reefs also means that there is less diversity. The invasive lionfish has the potential to disrupt entire food chains by reducing the abundance of species for which there is no ecological replacement. The potential here for extinctions and the wholesale alteration of reef communities cannot be overstated. Perhaps an early awareness of this invasive population coupled with a robust effort at removal can help stem the tide, but the example set in the Caribbean suggests otherwise.
What will happen when the lionfish establishes itself in some of the truly remote regions of the South Atlantic? Species like the Noronha Wrasse, the Oblique Butterflyfish and the Resplendent Angelfish have an even more precarious future with such an efficient predator now bearing down on them. One thing’s for certain, the lionfish did not travel to Brazil just to see Carnival.
Ferreira CEL, Luiz OJ, Floeter SR, Lucena MB, Barbosa MC, et al. (2015) First Record of Invasive Lionfish (Pterois volitans) for the Brazilian Coast. PLoS ONE 10(4): e0123002. doi:10.1371/journal.pone.0123002
