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| Author(s): |
Julia Myriam de Almeida Pereira
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) |
| Defense date: | 2005-11-11 |
| Examining board members: |
Miguel Petrere Junior;
Maria do Carmo Calijuri;
Edson Kiyoshi Okada
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| Advisor: | Miguel Petrere Junior |
| Abstract | |
In 2002 the total production of fish in the world was 133,0 million tons. In Brazil, the total volume of fish was of 822,2 thousand tons, with 26,5% coming from freshwater fisheries. The Lobo-Broa reservoir (Itirapina, Brotas, SP; 22°15'S, 47°49'W), can have the sustainability of their fishing resources changed due to the proximity of cities as São Carlos and Itirapina. The general objective of this work was to study the sporting fisheries and their fishing gears, to do experimental fisheries and to study the compositions of the captures of both studies. The work was presented in eight chapters: (1) presentation, (2) socioeconomic characterization of the sporting fishermen, (3) description of the captures of the sporting fisheries, (4) description of the captures of the experimental fisheries, (5) statistical analyses on the both fisheries, (6) preliminary survey of the selectivity of the gillnets used in the experimental fisheries, (7) handling of fishing resources in reservoirs and (8) final considerations and recommendations. Among September and November of 2004 it was applied 38 questionnaires for socioeconomic evaluation of the sporting fishermen and these indicated that the fisheries are practiced mainly by men whose standard of living resembles each other to the population average of the country. Among September of 2002 to September of 2004, 1027 interviews were did on the captures in the three main places of sporting fisheries (praia, píer and horto florestal). The sporting fisheries are practiced with simple fishing rod and with reel, mainly in horto florestal, place that presented larger captures and where was concentrated the largest fishing effort. The capture is composed of Ciclídeos (cará, Geophagus brasiliensis, tilápia do Nilo, Oreochromis niloticus, tilápia do Congo, Tilapia rendalli and tucunaré Cichla monoculus), mainly, although the reservoir has not elevated fishing productivity. The seasonal variation and the bait use were not shown statistically significant. For fish fauna composition evaluation of the reservoir, seven experimental fisheries were accomplished between November of 2002 and September of 2004 in three places (horto/Itaqueri, meio and barragem), using gillnets. The species that had larger relative captures were the cará and the lambari rabo amarelo (Astyanax altiparanae) and the area with larger relative captures was the horto/Itaqueri. The seasonal variation and the daytime-nighttime variation were not statistically significant. It was detected the factors and the covariates statistically significant (P<0,05) on the captures of the studies above, being tested two models of analysis of covariance with three factors (3 way ANCOVA). The selectivity of the gillnets study for each species, for mesh size showed that the nets were selective for the lambari rabo amarelo, lambari rabo vermelho (Astyanax scabripinnis paranae), sagüiru (Cyphocharax modesta) and cará. For species as tuvira (Gymnotus carapo), cascudo (Hypostomus sp) and mandi (Pimelodella cf gracilis) this fishing gear was not selective. It was believed that the sporting fisheries should be motivated aiming the increment of the tourism in the area and increase of the fishing productivity of the reservoir. A larger understanding of the fishermen is urgent so that the bait stop being used, once this practice doesn't increase the captures and contributed to the eutrofication process in the reservoir (AU) | |