Conhecimento ecológico local e distribuição espacial de tambaqui (Colossoma macropomum) em lagos de várzea da RDS Piagaçu-Purus, Amazonas

Abstract

Tambaqui (Colossoma macropomum) is a large Characidae which has its life cycle associated with white water rivers floodplain environments in the Amazon. Its populations has historically been the target of fishermen. More recently, due to the increasing fishing pressure in the last decades it has become necessary to develop strategies for the sustainable exploitation of this resource. Water zoning in lakes of use (fished) and lakes of preservation (no-take) has been used for this purpose in Protected Areas. In order to support sustainable management strategies in Amazon floodplain areas, the goal of this paper is to analize both the local ecological knowledge (LEK) of fishermen about tambaqui and the influence of environmental characteristics on the abundance of this species in zoned lakes located in Caua-Cuiuanã sector of Piagaçu-Purus Sustainable Development Reserve (SDR-PP). The paper is organized into two chapters. The first one investigated the LEK of fishermen on the SDR-PP tambaqui and the characteristics of their fisheries, in order to ascertain how this knowledge resembles or differs from scientific information and how this can contribute to the improvement of the co-management system of existing fishing on this reservation. Thirty-three fishermen were interviewed in 2013, when relevant information about folk taxonomic, habitats, displacement, reproduction, characteristics of the fishery and and rules for fisheries management tambaqui were provided by fishermen and then classified according to the level of agreement with scientific information already known. Useful informations ("insights") which have not yet been studied by science were also considered. Levels of concordance identified between scientific information and LEK about tambaqui open new perspectives for future ecological studies in the lower Purus river region and create opportunities to encourage the participation of fishermen, through the use of their empirical knowledge, in the co-management fisheries tambaqui. In the second chapter, the relative abundance of tambaqui and the population parameters were compared, as well as the influence of biotic and abiotic environmental characteristics on the spatial distribution of tambaquis from six preservation lakes and six lakes of use through experimental fishing conducted in 2012 and 2013. The zones do not differ of each other in limnological characteristics, but differ in structural characteristics and density of zooplankton. 196 individuals were captured, most from the preservation lakes. These lakes have more adults and individuals are greater in length and weight. The average values of CPUE between the lakes were statistically similar (p=0.06). The spatial distribution appears to be influenced by the density of the zooplankton (R²=0.53, p<0.03) and spatial distribution of zooplankton appears to be influenced by structural features (R²=0.66, p<0.001). The results show a relative success in the management model of RDS - PP and emphasize the importance of zooplankton in the distribution of tambaquis between floodplain lakes. Generally and considering the results of the two chapters, it is hoped that this information can contribute to the development of more effective strategies for conservation of the tambaqui in the Central Amazon.