9 resultados para embayed beach
em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"
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The reproductive cycle and recruitment period of a ghost crab population from Ubatuba, São Paulo, Brazil were investigated by means of examining the developmental stages of gonads of breeding crabs and the ingress of young recruits to the studied population. Monthly collections over a one-year period were carried out during nocturnal low-tide periods at Vermelha beach. The morphology of the abdomen and pleopods was used for sex determination. All captured crabs were measured for carapace width and dissected for the determination of the development stage of the gonads. A total of 582 specimens was captured: 271 males, 241 females, and 70 juveniles. Size ranged from 8.5 to 37.5 mm for males, from 9.5 to 39.2 mm for females, and from 5.8 to 12 mm for early juveniles. Median size of males and females did not differ statistically. The frequency of ovigerous females was markedly low. The onset of sexual maturity in females is achieved at around 23 mm of carapace width. Mature females with advanced gonad stages were not recorded from May to September. Recruitment of young was highest during summer, but the presence of early and late juvenile specimens throughout the year indicates that continuous recruitment is taking place in the studied population.
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This study provides information on the community structure of brachyuran crabs associated with the green sponge, Amphimedon viridis Duchassaing & Michelotti, 1864, from a beach on the south-eastern coast of Brazil. Monthly collections from May 2002 through August 2003 were carried out on the rocky bottoms off Itagua Beach (23 degrees 27'07 '' S 45 degrees 02'49 '' W). Crabs on the green sponge banks were hand-caught during snorkelling sessions, and 638 crabs belonging to 31 species, 19 genera, and 10 families were obtained. Biological parameters, including sponge volume, number of individuals, density, richness, diversity, evenness, and dominance changed considerably over time. Species recruitment and foraging habit are some of the factors that drive the richness, dominance, and diversity patterns of this community. The green sponge banks are important sites for recruitment, refuge, and feeding of many species of brachyurans. Therefore, they are also important for the conservation of this group on the south-eastern coast of Brazil.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Physical and chemical characteristics of intertidal sediments and their relationships with bacteria and cyanobacteria, were analyzed at four stations at Pereque Beach. Granulometric analysis showed that Pereque beach has sediment that is classified as sand. The lowest value of the sediment C/N rates (6.08), mainly due to a higher concentration of organic nitrogen, was found at the northern part of Pereque Beach, where organic matter of marine source was more prominent. In this area, density (9.6 x 106 cells cm(-3)), biomass (1992.04 ngC cm(-3)) and activity of bacteria were higher than at the southern end. In contrast, cyanobacteria density varied from 2.0 to 4.0 x 10(5) cells cm(-3), with biomass and total chlorophyll a of the sediment being higher at the southern part, where there are water input from Pereque River and higher organic matter of continental origin. The variability in the microbial population is discussed in the light of the sediment granulometry, organic matter quality, fresh water inflow and pollution. (c) 2007 Elsevier Ltd. All rights reserved.
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Modification showed by intertidal macrofaunal communities between two nearby sites that change from a wave to a tide dominated beach environment, was analyzed on the present study. At each site, eleven intertidal sampling stations were distributed along a transect, from the drift line to the spring low tide water level. Four macrofaunal samples one meter long-shore spaced were collected at, each station with an iron core of 0.05 m(2) surface area, taken to a depth of 20 cm. Major,differences on sediments between sites were the offshore decrease of mean particle size diameter and increase of kurtosis and water content at the tide dominated site. KIDS ordination showed major similarities between the lowest stations of this site, that represents the dissipative low tide-terrace portion of the beach. Two lower station of the wave dominated site presented similarities with this group. The other stations of the tide-dominated site, that represents the reflective high tide beach portion, grouped distant from the former. (canonical Correspondence Analysis (CCA) showed a similar spatial distribution of stations, suggesting the importance of environmental factors on the explanation of species distribution patterns. Sediment water content and water table depth, with the highest inertia value, seems to be the principal physical factor. Increase on water content affects the macrofaunal distribution by the expansion of typical infralitoral species, as was the case of Bathyporeiapus ruffoi, on the dissipative low tide terrace beach portion. A disrupted distribution with the lost of a gradate zonation along a physical gradient is one of the major modification presented by macrobenthic communities on the transition from a wave to a tide dominated beach environment.
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A floristic survey for the family Orchidaceae was undertaken in a coastal forest area of ca. 8 km2 in the Picinguaba Development Center of the Serra do Mar State Park, in the municipality of Ubatuba, Brazil. The sampling used all tracks and roads of the area, up to the altitude of 50 m.s.m. and resulted in 77 species distributed in 45 genera. The spacial distribution of the species was plotted in maps of the nine physiognomical units identified for the area, based on 1:8.000 and 1:25.000 aerial photographs, and field observations. The results are shown in 1:10.000 topographic charts. Ninety percent of the species occur in at least 3 physiognomical units while 60% only occurred in a single unit, what indicates that the orchids can be used to characterize the vegetation even in large scales.
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Bacterial resistance is a rising problem all over the world. Many studies have showed that beach sands can contain higher concentration of microorganisms and represent a risk to public health. This paper aims to evaluate the densities and resistance to antimicrobials of Escherichia coli strains, isolated from seawater and samples. The hypothesis is that microorganisms show higher densities in contaminated beach sands and more antimicrobial resistance than the water column. Density, distribution, and antimicrobial resistance of bacteria E. coli were evaluate in seawater and sands from two recreational beaches with different levels of pollution. At the beach with higher degree of pollution (Gonzaguinha), water samples presented the highest densities of E. coli; however, higher frequency of resistant strains was observe in wet sand (71.9 %). Resistance to a larger number of antimicrobial groups was observe in water (betalactamics, aminoglycosides, macrolides, rifampicins, and tetracyclines) and sand (betagalactamics and aminoglycosids). In water samples, highest frequencies of resistance were obtain against ampicilin (22.5 %), streptomycin (15.0 %), and rifampicin (15.0 %), while in sand, the highest frequencies were observe in relation to ampicilin (36.25 %) and streptomycin (23.52 %). At the less polluted beach, Ilha Porchat, highest densities of E. coli and higher frequency of resistance were obtain in wet and dry sand (53.7 and 53.8 %, respectively) compared to water (50 %). Antimicrobial resistance in strains isolated from water and sand only occurred against betalactamics (ampicilin and amoxicilin plus clavulanic acid). The frequency and variability of bacterial resistance to antimicrobials in marine recreational waters and sands were related to the degree of fecal contamination in this environment. These results show that water and sands from beaches with a high index of fecal contamination of human origin may be potential sources of contamination by pathogens and contribute to the dissemination of bacterial resistance.