7 resultados para Snorkelling


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Coastal ecotourism is one of the fastest growing leisure industries in the world and snorkelling is emerging as an important beach-based activity. Snorkelling has the potential to enhance biodiversity conservation when developed within environmental education framework. The aim of this study was to implement and evaluate snorkelling routes, in the Algarve (South Portugal), as a sustainable ecotourism offer. To achieve these objectives, three snorkelling routes were established at the pristine Marinha beach. After the diving experience, a face-to-face questionnaire survey was conducted to collect information about individuals' opinions regarding the underwater routes, their social demographic characteristics, ecological appreciation, opinions about beach facilities and trip expenditures. The survey was undertaken during the summer months of 2008 and 2009, and 202 people were interviewed. Data was analysed using univariate and multivariate statistic methods. Most respondents perceived the existence of routes to be good for the preservation of the local biodiversity and reported this experience as "good" or "excellent". The only difference in perceptions was observed by visitor snorkelling in groups of more than two people. Interviewers consider that emergency support and sanitary facilities are the most important beach support infrastructures. Overall, these routes seem to be an effective tool for developing ecological awareness in tourists, as they enhance the preservation and the understanding of the marine coastal environment.

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The use of natural areas for underwater coastal marine activities such as snorkelling is growing, but the amount of ecological and socioeconomic data on these activities is scarce and relates mainly to coral reef areas. Three underwater self-guided routes were designed at Marinha Beach (Algarve, Portugal), based on scientific information, with in situ interpretation and guidance, as a way to enhance biodiversity awareness and, hence, reduce the probability of human impacts. The routes were implemented in two consecutive summer seasons and after each season, visual census techniques were used to describe flora composition and cover area (seaweeds and seagrasses) in order to understand patterns and evaluate human impacts. Snorkelers' opinions and perceptions about several issues related to the routes' environmental education role (e.g. role in enhancing biocliversity awareness) were investigated by questionnaire after the snorkelling activity. An inter-annual difference inflora assemblages was found, probably associated to natural variability, rather than snorkelers' impacts. Results indicate that, in fact, in situ education and interpretation can raise environmental awareness if properly addressed, resulting in a satisfactory way of engaging snorkelers in the protection and in the conservation of the visited environments, thereby preventing negative ecological impacts. (C) 2015 Elsevier Ltd. All rights reserved.

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Repeatable and accurate seagrass mapping is required for understanding seagrass ecology and supporting management decisions. For shallow (< 5 m) seagrass habitats, these maps can be created by integrating high spatial resolution imagery with field survey data. Field survey data for seagrass is often collected via snorkelling or diving. However, these methods are limited by environmental and safety considerations. Autonomous Underwater Vehicles (AUVs) are used increasingly to collect field data for habitat mapping, albeit mostly in deeper waters (>20 m). Here we demonstrate and evaluate the use and potential advantages of AUV field data collection for calibration and validation of seagrass habitat mapping of shallow waters (< 5 m), from multispectral satellite imagery. The study was conducted in the seagrass habitats of the Eastern Banks (142 km2), Moreton Bay, Australia. In the field, georeferenced photos of the seagrass were collected along transects via snorkelling or an AUV. Photos from both collection methods were analysed manually for seagrass species composition and then used as calibration and validation data to map seagrass using an established semi-automated object based mapping routine. A comparison of the relative advantages and disadvantages of AUV and snorkeller collected field data sets and their influence on the mapping routine was conducted. AUV data collection was more consistent, repeatable and safer in comparison to snorkeller transects. Inclusion of deeper water AUV data resulted in mapping of a larger extent of seagrass (~7 km2, 5 % of study area) in the deeper waters of the site. Although overall map accuracies did not differ considerably, inclusion of the AUV data from deeper water transects corrected errors in seagrass mapped at depths to 5 m, but where the bottom is visible on satellite imagery. Our results demonstrate that further development of AUV technology is justified for the monitoring of seagrass habitats in ongoing management programs.

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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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We observed individuals of Odontostilbe pequira, a small characid, approaching and biting individuals of larger-bodied fishes of other species. This observation was made in two clear water headwater streams of the Cuiaba basin, Paraguay River system, located in Nobres, Mato Grosso State, Brazil, which led us to investigate the behavioral interactions of these fish. We characterized behavioral interactions between species by direct underwater observations using snorkelling and video recordings. Additionally, we proceeded diet analyses of O. pequira, obtaining intestinal coefficient and the index of alimentary importance. During underwater observations we checked the relative frequency of attacks by O. pequira on larger fish species. Odontostilbe pequira attacked individually or in large groups, and the anostomid Leporinus friderici was the preferred target prey species, while Prochilodus lineatus was apparently avoided. Our study sustains that O. pequira is omnivorous, with a diet that varies seasonally. It feeds mainly on plants, but also on animal prey, including the scales of small fishes, and, possibly, the mucus and epidermis of larger fish species. We suggest the term "mutilating predation" to describe the latter relationship.

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• Human/Wildlife Conflicts in Ethiopia -- Jeff Peter sen, Berryman Institute, Utah State University • NADCA 2004 Election • If the Norway rat (Rattus norvegicus) originated in Asia, why is this rat commonly called a Norway rat? • Book Review: When Raccoons Fall through Your Ceiling: The Handbook for Coexisting with Wildlife by Andrea Dawn Lopez. • Antarctic Scientist Dies in Seal Attack: Research scientist, Kirsty Brown was snorkelling in waters close to the Rothera Research Station as part of her studies when a Leopard seal pulled her under. • Giant Lizards Spreading Through the Gulf Coast: Cape Coral, Florida has become a haven for Nile monitor lizards, and their population, which continues to grow, has possibly reached the thousands in the Gulf Coast city. • Monkeypox Outbreak: An Alert • NADCA 2004 Ballot

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Elysia timida (Risso, 1818) colonizing the shallow waters of the Mar Menor Lagoon (Spain) exhibit a brown and a green morph. It was hypothesised that these morphs were the result of feeding preferentially on brown and green algae, respectively. E. timida and its potential food sources, Acetabularia acetabulum (Chlorophyta) and Halopteris filicina (Heterokontophyta) were collected by snorkelling during April 2010. Photosynthetic pigments were analysed by HPLC, photo-physiological parameters were estimated by PAM fluorometry and body colour was characterized by spectral reflectance. Digital photography was used to count the number and area of red spots (small red dots on the slug’s surface) on the parapodia of the 2 morphs. In the laboratory, green E. timida was fed with A. acetabulum cultured under 2 light treatments (high light, 600 µmol E m−2 s−1 and low light, 40 µmol E m−2 s−1), and digital photography was used to monitor colour alterations in E. timida. Spectral reflectance confirmed the colour differences, but both morphs showed a pigment composition similar to the green alga A. acetabulum and showed none of the pigments present in the brown alga H. filicina, neither immediately after collection of the slugs in situ, nor after the feeding experiment. A. acetabulum grown under high light intensity changed from green to brown colour and E. timida changed to brown colour when fed with high-light acclimated A. acetabulum. Thus, E. timida colour differences could not be attributed to feeding on different algae groups but was likely the result of feeding on A. acetabulum growing under different light intensities.