Relações ecologicas entre caranguejos e composição arbórea em bosques de mangue naturais e restaurados no nordeste brasileiro

This study aimed to compare the development of crab and tree communities of two restored mangrove areas, one planted with Rhizophora mangle and the other naturally recovered, and also to compare the predation of Grapsid crab Goniopsis cruentata and the Ocypodid Ucides cordatus over the propagules of three mangrove trees: Rhizophora mangle, Avicennia schaueriana e Laguncularia racemosa. Specifically, we tested the hypothesis that Goniopsis predation is more important that Ucides predation, and that these consumers have antagonist effects over propagule consumption. In each area, 10 quadrates were selected at random to analyze tree richness, diameter, height, tree biomass and crab richness and density five years after restoration experiment start. Results show that tree height, biomass and crab density were significantly higher in artificially restored area. No significant differences were observed in crab species richness between areas, but higher tree richness was observed in self-recovered area. Results suggest that planting propagules of Rhizophora can significantly increase tree recovering if the aim was increase tree biomass and crab density, which can accelerate return of ecological functionality. Goniopsis is a more important propagule predator than Ucides both in natural and restored areas. The effects of Goniopis were higher in absence of Ucides, due to negative interactions among these two predator species. The preference of Goniopsis by Avicennia and Laguncularia can favor the dominance of Rhizophora observed in Neotropical mangroves. This study suggests that propagule predation by Goniopsis should be controlled in restoration programs, if dominance of Rhizophora is undesirable respect to more rich tree communities

O histórico de uma pesca tropical utilizando indicadores ecossistêmicos

When scientists study methods, theory and standards in an inseparable form, he is facing a paradigm. Throughout the development of a determined science, paradigms can change by changing the methods, objective and standards of research. Fisheries science is changing the paradigm moving from the paradigm of maximization in the use of resources, quantified by the index of the catch, which was influenced by evolutionary concepts such as Optimal Foraging Theory, to the sustainability paradigm that seeks its foundation in the fishery ecosystem perspective. The goal of this study was to review methods, theory and the history of ecosystem indexes of fishery science that attempts to determine sustainability of fishery resources from the data capture. Ecosystems indexes by themselves may not be useful to measure the sustainability of fishing because they focus only on the environmental or ecological side of the sustainability tripod. Probably to measure the sustainability of fishing these indexes should include in the future the Payments for Ecosystem Services and Social Resilience. Thus the methods and theories are in constantly changing within science to meet the most current paradigm