Avaliação da produção e do impacto econômico do aumento do tamanho de captura no manejo de pirarucus (arapaima spp.) em sete áreas da Amazônia Central Brasileira

Abstract

In the Amazonas State, the economic management of Arapaima spp. (pirarucu) is an important environmental conservation strategy and an income source, being the most commercially representative fish for riverine communities. The legal rules based on minimum size, protective non-fishing period and an extensive commercial management carried out in Pirarucu Management Units (PMU), most located in public reserves, were important for the management of fishery resources in the Brazilian Amazon. Therefore, this study aimed to analyze the variation between years and PMUs in the number of fishes caught, the fresh meat mass commercialized and the total gross income for the sale of pirarucu. We also analyzed the different fishes size structure between PMUs and a possible impact on gross income with an increase of minimum legal length of the pirarucu commercialized. The study occurred between 2011 and 2014, analyzing managed fisheries in four Sustainable Development Reserves (SDR), one Extractive Reserve (RESEX), one Indigenous Territory (IT) and one Fisheries Agreement Area (FAA). The nature of the data was evaluated by extreme, mean and standard deviation. We analyzed information on total length (TL) and mass of 29.245 specimens of pirarucus, which 49% were originated from catches in 2013. Most specimens (32%) were captured at Maraã PMU, followed by Fonte Boa (25%), Área Focal (21%), Amanã (14%) and the others PUMs (3.2%). The total mass of all pirarucus amounted to 1,572.96 tons. The resulting gross income from the sale of pirarucu production during the study period was R$ 8,651,302, which 91% were issued from the four PMU located in SDRs evaluated. Most individuals (65%) were found in the total length class interval of 164-189 cm. Actually 150 cm is considered the minimum total length for a fish to be legally managed throughout all nine PMUs, but if the value of 170 cm (considered as the minimum reproductive size) is proposed, managers will have to exclude 13,517 individuals with a loss of R$ 3,539,494 for local communities. A less conservative proposal using minimum fishing length of 155 cm will results in the exclusion of 1,636 specimens and an amount loss of R$ 298,642.00. Our study might contribute to the improvement of participatory regulatory frameworks, to strengthen control over the management of pirarucu in the Brazilian Central Amazonia.