RESUMO
In this study, hypotheses concerning the use of beach ashtrays were experimentally tested. Results indicated that the mean rate of abandonment of this equipment was low (1.5 percent). The mean amount of cigarette stubs (3.4 items/ashtray) was greater than mean amounts of other types of litter. People with different socioeconomic profiles had different perceptions regarding the issues associated with beach debris. These results indicated that beach ashtrays could be useful to prevent the contamination of these environments and that differences in socioeconomic characteristics of beachgoers could partially explain the differences in perceptions regarding the presence of waste on the beaches. This information could now be used by coastal managers to plan strategies to reduce the marine contamination.
A presença de resíduos sólidos no ambiente marinho é extensa. Praias são tipicamente contaminadas com esses materiais, que podem causar impactos ecológicos. Resíduos sólidos nas praias podem causar ferimentos nas pessoas e podem prejudicar a atividade turística. Neste estudo, hipóteses relativas ao uso de cinzeiros de praia foram testadas. Os resultados indicam que a taxa de abandono desse equipamento é pequena (1,5 por cento) e que a quantidade média de pontas de cigarro (3,4 itens/cinzeiro) é maior do que as quantidades médias de outros tipos de lixo. Também se observou que pessoas com diferentes perfis socioeconômicos apresentaram percepções diferentes relativas à presença de resíduos sólidos nas praias. Estes resultados sugerem que cinzeiros portáteis podem ser um equipamento importante na redução da contaminação das praias e que diferenças socioeconômicas dos freqüentadores das praias podem explicar parcialmente as diferentes percepções relativas à presença de resíduos no ambiente praial. Sugere-se que os gerentes costeiros usem esse tipo de informação para planejar estratégias de redução desse problema.
RESUMO
Fatty acid components, in both the free and combined form of the intact tropical lichen Teloschistes flavicans, and its isolated photobiont and mycobiont, were analyzed by GC-MS of derived methyl esters. Its rDNA analysis confirmed that the isolated cultured symbionts belong to the genera Trebouxia and Teloschistes, respectively. The fatty acid composition of the lichen did not correspond to those found in the isolated symbionts, suggesting that the fatty acid metabolism is markedly influenced by the symbiosis. Differences in the fatty acid composition in the lichen were observed during the summer (27 degrees C), when the main fatty acids were saturated and in the winter (22 degrees C) when an increase of unsaturated fatty acids occurred. Similar differences of composition were also observed for the cultured mycobiont at different temperatures. The increase in the unsaturation level at low temperatures would maintain the membrane fluidity. Our results are the first on the fatty acids of a tropical lichen and suggest that it is sensitive to small temperature variations, which influences its saturated and unsaturated fatty acid composition.