Density, abundance and extractive potential of the mangrove crab, Ucides cordatus (Linnaeus, 1763) (Brachyura, Ocypodidae): subsidies for fishery management

Abstract

Ucides cordatus is a relevant fishery resource of Brazilian mangroves and requires legal normative to sustainable use based on stock assessment and management. This study evaluated some population parameters (structure, density, abundance, fishery potential and stock) of this crab species in Brazil Southeast (São Paulo, State), discussing the use of the results to delineate fishery management strategies. Density was monthly evaluated (September 1998 to August 1999), using five sample quadrats of 2x2 m. Density (ind.m-2) was indirectly estimated by counting the opened (with biogenic activity) and closed galleries, and contrasted with flooding level by tides using the vertical distribution of macroalgae in the base of trees. Density of U. cordatus ranges from 2 to 11 ind.m-2 (6±2 ind.m-2) and statistical difference occurred among monthly means (F=11.58; p=0.000). The relationship density vs. tidal flooding indicated a decrease of U. cordatus density in mangroves with higher levels of tidal flooding (r=-0.94; p=0.001). The total abundance of U. cordatus was estimated in 63.7 millions of crabs in 10.61 km2, with a reduction of 34.9% due to total mortality discount. Estimates like that are uncommon in literature, and could be used for fishery forecasts, allowing improvement by the introduction of new variables to be known in the future.

Are Crab-collectors in Mangroves of Northern Brazil (PA) Optimal Foragers?

“…A similar density of 1.2 U. cordatus per m 2 was described for the estuary of the São Francisco River (NE Brazil) by Santos et al (2018). Much higher densities of 6 m − 2 were found at the Coroa do Sapo Island of São Paulo state (Pinheiro et al 2018). Santos et al (2018) distinguished between crabs of commercially valuable size (based on burrow openings > 51 mm, representing a carapace width of > 60 mm; ≥65 mm carapace width, according to Diele et al 2005), reaching a density of 0.8 m − 2 , and those of smaller size, reaching only 0.4 ind.…”

Development of Biological Sciences at the AABC

“…Since only articles appear in the 2019-JCR, I have restricted the present analysis to those. As expected, the scope of the published articles vary tremendously, from extractive potentials regarding the biota of mangroves (e.g., Pinheiro et al 2018) and studies on the influence of rainfall on vegetation dynamics (e.g., Salimon & Anderson 2018), to new information of extinct reptiles (e.g., Chavarría-Arellano et al 2018). A total of 27 articles were cited at least once during 2019, resulting in an Article Citation Factor for Biological Sciences (ACF, see Kellner 2020) of 0.4154.…”

Meio Ambiente, Sustentabilidade e Tecnologia - Volume 13

“…A densidade e abundância dessa espécie em áreas de mangue são influenciadas por fatores abióticos, bióticos e antropogênicos. Entre eles, destacam-se o nível de maré de enchente, a pressão da pesca, o estado de conservação do mangue e a composição da vegetação (Pinheiro et al, 2018), fatores que podem variar entre os setores, e que evidencia que diferentes estratégias de manejo da pesca de U. cordatus devem ser utilizadas em setores distintos (Tabela 2).…”

“…Ucides cordatus desempenha importante função socioeconômica à pesca artesanal costeira no Brasil, sendo sua captura uma das atividades extrativistas mais antigas em áreas de manguezais (Pinheiro & Fiscarelli, 2001), além de ser uma espéciechave desses ecossistemas, onde desempenha um valioso papel ecológico, consumindo e degradando mais da metade da serapilheira disponível sobre o sedimento local (Krizek, 2021). Apesar dessa importância, vários estudos indicam uma redução expressiva dos estoques naturais dessa espécie (Pinheiro et al, 2018), fazendo dela uma espécie ameaçada de extinção. Neste contexto, em 2011 o IBAMA publicou uma proposta de Plano Nacional de Gestão para o Uso Sustentável do Caranguejo-Uçá, o qual sugere que sejam implantadas para este recurso nos sistemas estuarino-lagunares brasileiros Áreas Extrativistas (AEs) e de Exclusão de Pesca (AEPs), por meio de técnicas de geoprocessamento, sensoriamento remoto e de informações já disponíveis para esta espécie (IBAMA, 2011).…”