A substituição das técnicas tradicionais de captura do caranguejo-uçá (Ucides cordatus) pela técnica “redinha” no estuário do rio Mamanguape, Paraíba

Abstract

Two traditional fishing communities situatedon the margins of the Mamanguape River estuary-mangrove complex, Paraiba State, Brazil, were studied to determine themotivations for their rapid transition from traditional harvesting techniques (braceamento and tapamento) to redinha(little-net) trapping. Our results indicate that the crab harvesters were prompted into changing their techniques primarilydue to higher production rates with redinha. Additionally, there were disadvantages in using both the braceamento andtapamento techniques (including greater chances of accidents and acquiring diseases) that reinforced this transition. Thebehavioral characteristic of the crabs living in denser gallery forest specifically hindered capture using the braceamentotechnique. This fast transition of harvesting techniques is a major concern from a conservation standpoint as the redinhacauses environmental impacts and threatens both the mangrove ecosystem and the populations of caranguejo-uçá crabs(Ucides cordatus). Thus this study examined a problem that is both environmental and social, as traditional techniqueswere less profitable than the new harvesting method but had much less impact – while the redinha helps with crabharvesting and increases income at the cost of higher environmental impacts.

Caracterização socioeconômica e percepção ambiental dos pescadores artesanais do município de Canguaretama, Rio Grande do Norte – Brasil.

“…das tocas dos caranguejos com sedimentos do mangue que são inseridos para o seu interior com o auxílio dos pés. Após a tapagem, os catadores retornam às tocas para fazer a coleta (Nascimento, Mourão, & Alves, 2011 Em todos os meses de janeiro desde 2004, há a "Caiacada Ecológica", que propõe a limpeza do rio, nº 40 -2019 em que inúmeros caiaques, pranchas de stand up e barcos participam. Apesar do lado positivo da interação do ser humano com a natureza, seja por meio do turismo ou esporte de aventura, o aumento do número de praticantes nesse evento e o uso de fogos de artifício podem resultar em uma exploração ainda maior do meio natural dessa região.…”

Crab gatherers perceive concrete changes in the life history traits of Ucides cordatus (Linnaeus, 1763), but overestimate their past and current catches

“…Probably, that happened due to the illegality of this gear, considered predatory even by the same gatherers interviewed. The use of this technique has been considered damaging to the environment because it maximizes the catching pressure (Jankowsky et al 2006), does not select the size or sex of the crab, pollutes the mangrove area, when the remaining material is disposed anywhere, and causes deforestation, as mangrove roots are used to fix this trap (Botelho et al 2000;Nascimento et al 2011). In another state of Brazil (Pernambuco), for example, it is estimated that one gatherer uses, on average, 130 redinhas/day and spends 18 days per month catching crabs, which results on 28,080 redinhas/year/ gatherers (Botelho et al 2000).…”

“…The redinha can, on the other hand, maximize their success. The crab gatherers from Paraíba, another Brazilian northeastern state, gave reasons to explain why they prefer to use the redinha instead of the traditional methods, citing for example higher catches, how easy it is to use this method and how fast they can catch a crab with it (Nascimento et al 2011).…”

Habits and customs of crab catchers in southern Bahia, Brazil

“…Brachyura crustaceans, which are the most abundant animals found in the mangrove ecosystem [11], have great economic importance to the communities that live in estuarine areas [12–14]. The mangrove crab ( Ucides cordatus ) (Linnaeus, 1763) is a particularly important economic and subsistence resource found in all Brazilian mangrove forests [5, 15–24].…”