636 resultados para Bathing Beaches


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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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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The arrival of migratory shorebirds on beaches in urban communities in developing countries is a current challenge for the protection of these migrant birds. Nearctic-Neotropical migrants rely on roosting and feeding sites during their stopover on wintering sites in the Southern Hemisphere to acquire sufficient energy to complete their migratory cycles. On the other hand, cities in the Southern Hemisphere are growing rapidly, which results in increasing competition for space between humans and birds, such as for use in beach habitats. In the present study, I analyze the probability for occurrence for Nearctic-Neotropical migratory birds relative to the number of people in southeastern Brazil, the most populated region of South America. The frequency of occurrence of migrants, their distance of tolerance to people and the number of people were recorded in sample areas (circle plots with 20 m radius) on a 9 km stretch of urban beaches from November to February from 2009 to 2013. The probability of occurrence of Nearctic birds decreased as the number of people increased. When the number of people exceeded 20, the probability of occurrence of birds was almost zero. Furthermore, more than 95 % of birds moved off when people were within 16 m of reach. These results are discussed in the context of conservation actions since no management plan has been developed for migrant shorebirds that use urban beaches as stopover or wintering sites in developing countries.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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There are few environmental studies using biomarkers for the species Atherinella brasiliensis in Brazil. In the present work, the presence of hepatic histopathological lesions and nuclear abnormalities in erythrocytes were investigated in A. brasiliensis from Lamberto, a beach under influence of domestic wastes and marine activities. For comparison, fish were also sampled in Puruba, a non-polluted beach, located in the northeastern of Sao Paulo State. The frequency of lesions found in liver was in higher numbers in individuals from Lamberto than Puruba beach. The most critical injuries observed in A. brasiliensis were the presence of necrotic areas, leucocytes infiltration and piknotic nucleus. A high occurrence of cells with vacuolization was also observed. The hepatic lesion index of the fish from Lamberto beach showed significant high values (I(org)=13) when compared with fish from Puruba beach (I(org)=7) suggesting the influence of the several human activities in the studied site. Notched and blebed nucleous were observed in this study, and significant differences were found between the studied sites. However, these differences did not reflect the total nuclear alterations.

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This paper presents a comprehensive review on the interaction between hydrodynamic processes, beach morphology and sedimentology at large scale coastal behaviour along the coastline of Santa Catarina, between Laguna and Sao Francisco Island, a microtidal east coast swell environment with headland and bay geomorphologies. The parabolic bay shape equation has proven to be a convenient and practical tool for studying the stability of the headland-bay beaches, tombolos, and salients in Santa Catarina. The beaches exhibit different patterns of sediment removal as a function of the degree of beach curvature. In highly curved beaches, there is a well-developed shadow zone and a range of morphodynamic conditions, from a sheltered low-energy beach adjacent to the downdrift headland to a high-energy exposed beach on the straight end of the headland-bay beach. The less curved beaches instead, tend to show more uniform behaviour since they are directly exposed to incident waves. There is no obvious relationship between average wave height and mean grain size, showing the importance of sediment source to characterize the sedimentary distribution patterns in the study area. The analysis of beaches showed that beach morphodynamics and sequence profiles for a bay-headland coast in a microtidal east coast environment is a function of geological inheritance (e.g., distance between headlands and orientation, nearshore and inner shelf morphology, coastal plain morphology, and sediment source), and hydrodynamic factors (wave conditions, oceanic wave exposure and relative tidal range). (C) 2009 Elsevier B.V. All rights reserved.

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This study aimed to assess the sanitary quality of water, and wet and dry sand from three beaches located in the South Coast region of Sao Paulo State, Brazil, selected taking into account the frequency of tourists and the water quality (good, fair and poor). Thirty-six water samples each of wet and dry sand and seawater were collected monthly over a period of one year and analyzed for fecal indicator bacteria (FIB: thermotolerant coliforms, Escherichia coli, and enterococci), presumptive Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and dermatophytes. The results revealed FIB concentrations more elevated in dry sand followed by wet sand and water. P. aeruginosa and presumptive S. aureus were detected with a similar frequency in water and sand samples, but maximum concentrations and geometric means were higher in dry sand. C. albicans was detected only in water samples whereas the dermatophyte Microsporum sp. was isolated exclusively from dry and wet sand samples. This evaluation showed also that the environment had a significant influence on P. aeruginosa but not on presumptive S. aureus concentrations. According to threshold values proposed in the literature for E. coli and enterococci dry sand densities, none of the beaches would be considered of sufficient quality for recreational activities.

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[EN] Playa Barca is a 370 m long beach located within the system of the Leeward beaches on the Jandía peninsula, Fuerteventura. This system of beaches represents one of the major sources of economic income to the island, both because of its natural landscape that attract a specific type of tourism, and because of its particular climate conditions that make these beaches ideal for practicing wind-water sports. Nevertheless, in the past decades, this area has suffered from a significant and worrying coastline retreat. In order to look for an explanation to this retreat, five topographic surveys were carried out in October 1999, February 2001, February 2002, February 2003 and February 2013 to track the beach behavior in the last 15 years. A total station Topcon GTS-303D was used for this purpose. Surveys were carried out during low spring tides, so that the outer limit was the furthest possible depending on wave conditions. The inner limit covered part of the dunes in the backshore. From these topographic data both coastline changes and the sedimentary balance have been obtained.

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Raised beach ridges on Livingston Island of the South Shetland Islands display variations in both quantity and source of ice rafted detritus (IRD) received over time. Whereas the modem beach exhibits little IRD, all of which is of local origin, the next highest beach (similar to250 C-14 yr BP) has large amounts, some of which comes from as far away as the Antarctic Peninsula. Significant quantities of IRD also were deposited similar to 1750 C-14 yr BP. Both time periods coincide with generally cooler regional conditions and, at least in the case of the similar to250 yr old beach, local glacial advance. We suggest that the increases in ice rafting may reflect periods of greater glacial activity, altered ocean circulation, and/or greater iceberg preservation during the late Holocene. Limited IRD and lack of far-travelled erratics on the modem beach are both consistent with the ongoing warming trend in the Antarctic Peninsula region.