Parâmetros populacionais do caranguejo-uçá Ucides cordatus (Linnaeus, 1763) em manguezais de áreas urbanizadas

Abstract

The objective of the present study was to analyze the Ucides cordatus cordatus population dynamics (Linnaeus, 1763) as a component of population structure and contribute information to the management and sustainable management of this resource in mangroves are located along the Vitória Bay (ES). The collections were made between the months of February to May 2017. For the study were established twelve fixed plots perpendicular to the course of tide with an area of 60 m ² (10 x 6 m) in seven separate locations, totaling 720 m² of mangrove forest. The population density was held from the count of galleries based on the observation of those who owned biogenic activity. In addition to the biometric measures density of crabs were converted from smaller and larger diameter of the opening of the galleries. The average population density observed for this study was 1.50 ± 0.90 ind.m². Between the months, the lower population density recorded was for the month of May (1.32 ± 0.72 ind.m²) and highest in February (1.83 ± 1.12 ind.m²) Although the Kruskal-Wallis test showed no significant difference between the months sampled (p = 0.546), by the other hand, there was a significant difference between the plots (p = 0.002). Were expensed 4,316 galleries U. cordatus, of this total, 81% of the galleries were open (n = 3,483) and 19% (n = 833) during the sampling period. The Chi-square test (? ²) showed significant difference between the open and closed galleries, to sampling areas and between the months sampled. To the population size, were measured 1.420 galleries of U. cordatus, in all areas of sampling, the transformation of these measures resulted in an average size of 5.97 ± 0.14cm. For this parameter the Kruskal-Wallis test showed significant difference between the months sampled (p = 0.009) and between the areas of sampling (p = 0.000). 665 galleries were registered which had sizes compatible with commercial-sized individuals (greater than or equal to 6.0 cm) and total commercial density was 0.92 ± 0.46 ind.m². For commercial density the Kruskal-Wallis test showed significant commercial density difference between the areas sampled (p = 0.036) and there was no significant difference between density the months sampled (p = 0.464). This difference in the densities of the land crab can be linked to several factors such as environmental quality, pollution, the use of predatory techniques, increasing the capture effort and the lack of supervision by the competent bodies in each parcel sampled along the Bay of Vitória. The lack of public policies for the management and the management of fisheries resources depicts the need for constant monitoring that may assist in shared management and thus improve the sustainability of activities integrating communities traditional, environmental agencies and research institutions.