Browsing by Author "Oliveira, F."
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- Developing self-guided scuba dive routes in the Algarve (Portugal) and analysing visitors' perceptionsPublication . Rangel, Mafalda; Pita, C. B.; Gonçalves, J. M. S.; Oliveira, F.; Costa, C.; Erzini, KarimScuba diving allows for underwater visitation of cultural and natural resources. Underwater routes can be used as a tool for guided and supervised underwater visits. Two scuba diving routes were implemented in the Algarve (South of Portugal), the "B24" and "Poco" diving sites. The perceptions of scuba divers regarding several aspects of the routes and the existing support infrastructures were studied following a survey carried out through face-to-face interviews from 2008 to 2012. Divers profile and their perceptions were analysed using 246 valid questionnaires. Divers were mainly Portuguese, over 30 years old and with more than 12 years of formal education. Some of the support infrastructures did not achieve a "good" or "acceptable" grade. This should be carefully considered by diving operators and managers, because perceptions tend to circulate throughout the diving tourists. All features of interpretative slates were graded as highly satisfactory. Overall, diver satisfaction increased slightly after route implementation, with an average ranking of "good". These findings support the implementation of underwater routes as a way to promote diving activity, and to increase divers' environmental education and awareness. (C) 2013 Elsevier Ltd. All rights reserved.
- Eco-touristic snorkelling routes at Marinha beach (Algarve): Environmental education and human impactsPublication . Rangel, Mafalda; Pita, C. B.; Gonçalves, J. M. S.; Oliveira, F.; Costa, C.; Erzini, KarimThe 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.
- Feeding habits of the deep-snouted pipefish Syngnathus typhle in a temperate coastal lagoonPublication . Oliveira, F.; Erzini, Karim; Gonçalves, J. M. S.Feeding habits of Syngnathus typhle were determined based on monthly sampling during experimental fishing in a coastal lagoon (Ria Formosa, South Portugal) from April 2004 to May 2002. The gut contents of 856 individuals were analysed and quantified with numerical and gravimetric methods, as well as with some complementary indices and measures (vacuity, fullness and relative importance). In this study, this species fed mainly on Copepoda, Mysidacea, small caridean grass shrimps (Hippolytidae and Palaemonidae) and small fishes (Gobiidae) and to a lesser degree on other small invertebrates. No significant differences were found between the diets of males and females. However, significant differences in the fullness indexes of both sexes were observed during the reproductive period. Significant differences in the diet among seasons were also verified but no seasonal trends were discovered. Snout length showed a linear increase with growth while mouth area and total length displayed an allometric relation. Mouth shape varied between an ellipse and an almost perfect circle. The increase in mouth area and snout length as S. typhle grows contributed to the observed ontogenic diet shift with specimens smaller than 10 cm feeding almost exclusively on Copepoda, medium sized specimens feeding mainly on Hippolytidae and Mysidacea, while larger specimens preyed on Hippolytidae, Palaemonidae and Gobiidae. Prey size generally increased with size of S. typhle. (c) 2007 Elsevier Ltd. All rights reserved.
- Length-weight relationships of six syngnathid species from Ria Formosa, SW Iberian coastPublication . Vieira, RP; Monteiro, P.; Ribeiro, J.; Bentes, L.; Oliveira, F.; Erzini, Karim; Gonçalves, J. M. S.In this study, the length-weight (LWR) parameters were estimated for six syngnathid species, including 2 seahorses and 4 pipefishes, from Ria Formosa, a temperate lagoon from the south coast of Portugal. A total of 5070 fishes were used to determine the LWR. The estimated b value ranged from 2.95 (Nerophis ophidion) to 3.36 (Syngnathus abaster). To the authors' best knowledge, LWR parameters were estimated for the first time for Nerophis ophidion and Syngnathus typhle for the Atlantic waters. Data here present are essential for management and conservation of these flagship species.
- Planning forest recreation: environmental economic instruments and the public participationPublication . Oliveira, F.; Pintassilgo, P.; Mendes, I.; Silva, joão; Brebbia, C. A.; Pineda, F. D.In Portugal there is a growing demand for natural areas that provide a wide range of outdoor recreation. This paper focuses on the particular case of the Mata Nacional de Leiria (Leiria National Forest). This is a pine tree forest with 11,000 hectares and eight centuries of history. It has always been a public forest with open access to everyone, a fact that contributes to different kinds of use and benefits (walking, cycling, picnics, collecting firewood, fruits and berries, and other recreation activities). The proximity to a major urban and industrial centre, on one hand, and to a very popular beach coast, on the other, makes this a resource that is widely used by both residents and visitors. In the future there is the possibility of implementing a set of actions to improve forest amenities and recreation, and later the emergence of environmental tourism activities and equipment. In this context, we want to know the economic valuation that actual users attach to these recreation improvements, but also realize their preferences and opinions regarding this project. For this purpose we designed, tested and applied a double bounded dichotomous choice contingent valuation questionnaire. The results presented in this paper focus on responses to attitudinal and follow-up questions. More than 70% of respondents have positively assessed the proposed improvements to the study area and about 40% enhanced their personal opinion on the type of interventions that they consider most appropriate. Answers focus the priority areas of intervention in the Mata Nacional de Leiria, the main concerns in its development, the type of actions that should (and should not) be implemented, respondents willingness to actively take part and, also, what the public authorities' role should be. At this stage, where Mata Nacional de Leiria is being considered in terms of future recreation and tourism offers, the results obtained provide important contributions and enhance the contingent valuation survey as a tool to support recreation planning, promoting public participation and the political decision-making process.
- Weight-length relationships for 54 species of the Arade estuary, southern PortugalPublication . Veiga, Pedro; Machado, D.; Almeida, C.; Bentes, L.; Monteiro, P.; Oliveira, F.; Ruano, M. Graça; Erzini, Karim; Gonçalves, Jorge Manuel SantosP>Weight-length relationships (WLRs) are presented for 54 species sampled by several types of fishing gear between February 2004 and May 2007, in the Arade estuary (southern Portugal). WLRs for six species are presented for the first time.