O uso de réplica no estudo da ictiofauna de uma planície de maré

Em uma planície de maré, a análise comparativa das capturas mensais de peixes, obtidas em dois arrastos consecutivos com uma rede do tipo picaré, não revelou ao longo do ano, diferenças significativas entre amostragens. Este foi considerado um forte indício de que a assembléia de peixes capturada foi a mesma em ambos os arrastos. ABSTRACT Comparative analysis of monthly samples obtained with two drags of a seine net in a tidal flat, did not indicate significantly differences between drags, indicating that the same fish assemblage was sampled. RÉSUMÉ Dans un bassin inondé par la marée, lanalyse comparée des captures mensuelles de poissons, obtenues par deux coups consécutifs avec une seine de plage, na pas montré des différences significatives au cours de lannée, montrant ainsi que cest le même assemblage de poissons qui a été échantillonné

Fishes collected with an artisanal fish trap in Barra de Camaratuba estuary, northeastern Brazil

A list of the species of fishes collected in the Barra de Camaratuba estuary, Paraiba, Brazil, is presented.Specimens were collected on a monthly basis between January and December 2012, using a fishing technique known locally as “Tomada”, an artisanal fish trap like a barrier. Forty species were collected, belonging to 27 genera and 20 families of the Teleostei. The Gerreidae was the most representative family, with 6 species, followed by the Lutjanidae and Tetraodontidae, with four species each

Fishes collected with an artisanal fish trap in Barra de Camaratuba estuary, northeastern Brazil

A list of the species of fishes collected in the Barra de Camaratuba estuary, Paraiba, Brazil, is presented.Specimens were collected on a monthly basis between January and December 2012, using a fishing technique known locally as “Tomada”, an artisanal fish trap like a barrier. Forty species were collected, belonging to 27 genera and 20 families of the Teleostei. The Gerreidae was the most representative family, with 6 species, followed by the Lutjanidae and Tetraodontidae, with four species each

Environmental and subtidal fish assemblage relationships in two different brazilian coastal estuaries

The general structure and organization of the shallow water (<1.5 m) fish assemblages were studied in two southern Brazilian ecosystems, a bay and a lagoon, under different marine or continental influences. The abiotic factors were measured to define the hydrology of the sites and the biotic descriptors were evaluated to characterize the assemblage structures. Transparency, salinity and organic matter were the abiotic factors which best distinguished the sites. A total richness of 69 species was observed. Ecological guilds, density, diversity and evenness indices values were different at each site. The hydrodynamism and geomorphology determined the structure and the organization of the fish assemblages in these shallow waters. It was observed that the variations in the hydrological attributes generated by the marine or continental water movements were able to alter the conditions in the lagoon more quickly and at more regular frequencies than those in the bay

Structure and Dynamics of Fish Assemblages in a Tidal Creek Environment

Studies were carried out on structure and dynamics of fish assemblages in the Baguaçu tidal creek, Paranaguá Bay, Brazil. A total of 30,104 fish were captured, comprising 21 families and 47 species. Both in weight and in number, the species Anchoa parva prevailed. Monthly captures in number and weight were largest in the autumn and part of the winter. No seasonal tendency was observed in the indexes of community structure. The dendrogram produced by the classification of the samples separated the 12 months of collection into three groups, reflecting differences in the qualitative and quantitative occurrences of the most important taxa. Some ecological likeness, not only seasonal patterns of abundance, seemed evident in the seasonality of the groupings of species revealed through the cluster analysis. The principal component analysis reflected mainly the periods of rain and drough

Fish assemblages in a tidal flat

Studies were carried out on fish assemblages in a tidal flat. Samples were obtained monthly at low tide of the half moon in the tidal flat of Paranaguá Bay, Brazil, with two seine nets, one with a 1 mm mesh, 30 m in length and 3 m in height and another with a 10 mm mesh, 65 m in length and 2 m in height. A total of 8,890 fish were captured, comprising 24 families and 53 species. The most abundant species were Harengula clupeola and Atherinella brasiliensis, which represented 63.4% of the total, capture. A seasonal tendency was observed in the abundance of fishes, with less fishes being captured during winter and part of spring. The number of species showed a seasonal pattern, with the gradual decrease through winter and a marked increase in summer. The community structure index indicated seasonal changes in the assemblage. The faunistic similarities between months separated the 12 months into four major groups. The seasonal pattern was apparent in the numerically dominant species and the Cluster Analysis revealed five main groups

Introducing fuzzy set theory to evaluate risk of misclassification of land cover maps to land mapping applications: Testing on coastal watersheds

In land cover maps, categories represent a continuum of variation and for this reason, fuzzy set theory, which accepts degrees of membership, has been suggested for land classification. Nevertheless, classical set theory, which only assumes single map categories, is still widely used. The purpose of this study is to develop a methodology to reduce the weakness of land cover maps in which classical theory has been applied. To do so, we propose adding an error relevance step after accuracy assessment, which evaluates how relevant are the classification errors to selected land applications. First, a membership matrix is built based on a linguistic scale associated to land cover rates obtained from literature. Then, two fuzzy measures are calculated and the frequency of categories, that do not pose a problem to the user in light of the land application, is determined. The methodology is demonstrated using two Brazilian tropical coastal regions and two land applications relevant for coastal watershed management. The study presents land cover maps of the Mamanguape and the Paraíba estuarine regions, their full accuracy assessment, and the relevance of the classification errors to the land applications. The accuracy assessment step has demonstrated that the land cover maps are reliable. The error relevance step has shown that the map weakness can be reduced. Both steps show that the land cover maps produced are suitable for further land mapping applications. The results on land cover composition point to the importance of future work focused on the environmental sustainability of the studied regions. The new procedure has proven useful to decrease the degree of distrust with which land cover maps are regarded. The framework provided is suitable for virtually any land mapping application.AD1D-1E23-B6C4 | Zara Fani Gonçalves TeixeiraN/