Estudo da sustentabilidade do uso de Sisal - Agave sisalana na prática de pesca no rio Licungo

Abstract

The present work is entitled: ʺStudy of the sustainability of the use of sisal (Agave sisalana) in the Licungo river fishing practice ”. A harmful practice, characterized by choking and killing fish within minutes. Therefore, the objective of the work is to investigate the possibility of making this activity sustainable. There was thus a trip to the field where 10 fishermen were heard to better understand the procedures of sisal fishing practice and collect 5kg of the sample of Agavaceae sisal family, Agavoidea sub-family Agave genus and subgenus Euagave. The sample was subjected to the following processes: root separation, drying, weighing and direct application of the following dosages: (1.575g, 1.181g, 0.787g, 0.393g and 0.196g) corresponding to 100%, 75%, 50%, 25 % and 12.5% respectively, in relation to the quantities used by fishermen. These quantities were placed in 6 buckets each containing 15ml of water and were tested in 2 trials with 18 samples of tilapia fish of different sizes. The above calculations were made based on the proportions from the quantities used by fishermen 25kg of sisal for an area of (14x17m), height 1m and 238000ml of water. The results obtained from the tests show that the dosages 1.575g, 1.181g, 0.787g, 0.393g and 0.196g, equivalent to 24.99kg, 18.73kg, 12.48kg, 6.23kg and 3.10kg. They cause the fish to die within a range of 3: 30-5: 21, 6: 02-12: 20, 7: 17-13: 08, 8: 01-18: 58 and 11: 41-18: 26 respectively. It is concluded that fishermen use very high doses of sisal; Even at low doses, fish deaths do not depend on size; Different amounts of sisal cause fish to die at different times and some undesirable fish can be caught and returned to the natural environment during the stress period, making the practice sustainable.