Ethnoecology, gathering techniques and traditional management of the crab Ucides cordatus Linnaeus, 1763 in a mangrove forest in south-eastern Brazil

This study presents the ethnoecology of the crab Ucides cordatus Linnaeus, 1763 through the perception of traditional gatherers in a mangrove forest of northern Rio de Janeiro, south-eastern Brazil. The study also describes gathering techniques and assesses the development of traditional management actions. A total of 66 ethnographic interviews was performed, from which the gatherers' ability to correctly identify the target species and describe aspects of its biology, ecology and behavior was determined. The gatherers who collect U. cordatus in this mangrove forest are primarily female, and the techniques applied include the 'redinha' or net method, the 'braceamento' or arm method, and the 'mão' or hand method. Crab gatherers have developed a traditional management system based on selective gathering according to the sex and size of the animals and the establishment of fallow areas in the mangrove forest. This system facilitates the long-term sustainability of the gathering activity. The existence of a traditional management system in this crab-gathering activity illustrates the fact that traditional knowledge can be applied in the conservation process. Integration of traditional knowledge with scientific knowledge plays a critical role in the development and execution of management plans. This study established a network of relationships between research institutions, the Fishermen's Colony and the community. The acknowledgment of this traditional management system allowed the recognition of certain key individuals who will facilitate the elaboration of educational programs. These local actors can be community members who disseminate ideas and help with decisions related to fishery management. Traditional knowledge can help researchers to understand the environmental conflicts and interests of a community. The union of this knowledge with scientific information can provide support for defining conservation strategies and elaborating laws and thus might improve management plans.