Tuesday, September 29, 2015

Knowing where the parrotfish are: modeling sensitive parrotfish (Labridae: Scarini) habitats along the Brazilian coast

Parrotfish (Labridae: Scarini) are large (and beautiful!) herbivorous fishes that play a critical functional role in reef environments when they feed.  By grazing on algae, they actively affect the structure and composition of benthic communities, mainly by maintaining algae  free corals. Even though these species used to have relatively low commercial interest in the past, when others, more appreciated and usually higher in the food chain (e.g.: predators) were available, they are now a favorite target. This is true for many parts of the world, including Brazil, where parrotfish have been increasingly exploited, with many of them already showing signs of depletion. In particular, three species, Scarus trispinosus (Valenciennes, 1840), Sparisoma frondosum (Agassiz, 1831) and Sparisoma axillare (Steindachner, 1878), currently labeled as threatened, have been intensively targeted in Brazil, mostly on the northeastern coast. 
That means we have to care about parrotfish as well, before they suffer the same fate as other large predatory fish fished to their commercial exhaustion. One way to do that is through an ecosystem approach, which, in the case of reef fisheries should include careful marine spatial planning of reef use to ensure the protection of the relevant habitats of key species. For that, it is a requirement to have a solid knowledge of species-environment relationships and to identify priority areas for conservation and management. The article “Modeling sensitive parrotfish (Labridae: Scarini) habitats along the Brazilian coast” maps the distribution of these three parrotfish species, showing their hotspots of occurrence along the Brazilian coast.
The modeling results brought about the most sensitive habitats along the Brazilian coast that indicate the best areas to be protected. Specifically, this study confirmed the suitability of existing marine protected areas, such as Parcel Manuel Luís, Atol das Rocas, Fernando de Noronha, Abrolhos Archipelago, and Trindade. It also indicated the potential of enhancing the protection in such locations, including its surrounding areas and buffer zones, besides suggesting the full protection of some some additional hotspots. 
However, the article did not disregard the fact that today there is an important group of fishermen that depends on parrotfish exploitation and that simply closing all important areas could have the fishermen deemed illegal and could threaten their wellbeing. Therefore, it is suggested that, in addition to establishing new protected areas, fishery management should focus on measures that regulate fishing operations, such as temporary closures and restrictions on non-selective fishing gear in unprotected places. The way to assure that these species continue performing their ecological role while also being part of our diet may require a compromise between different degrees of conservation measures (e.g., permissive vs. restrictive). 
Now we know where to protect such important species in Brazil and we also suggest the first steps on how to do it. The question is: who will take the next step?

by Natalia C. Roos

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