Migração e conservação do dourado (Salminus franciscanus, Lima & Britski 2007) em um trecho do Rio São Francisco

Abstract

Dourado (Salminus franciscanus) is one of the most important fish for commercial and 2 recreational fisheries of the São Francisco river basin. From late 2005 to early 2007, dourados (n=107) were captured near the Abaeté river mouth (Pontal), tagged (n=41) and tracked 4 (n=33) in the São Francisco river between the cities of Três Marias and São Romão. The objectives were to determine dourado linear home range, to detect seasonal differences in 6 movements and identify homing behavior for dourado. An experimental fishery was also carried out in order to determine periods and locals of higher capture of dourado. 8 Dourado home range varied from 4,6 to 243,6 km and they performed movements near to 35 km between November and January. These movements were related to pre-10 spawning, spawning and post-spawning events. During non-reproductive period, movements were reduced to less than 3 km. Homing was detected during the same reproductive period, 12 same non-reproductive period and between reproductive periods. Higher captures of dourados occurred at Pontal and October. Fishery is prohibiting by 14 law on the tributaries mouth, but October is not included in the period of prohibition of fishing. The relation between captures and water level of São Francisco and Abaeté rivers showed 16 that most captures occurred when São Francisco was stable and Abaeté flooding. The construction of dams on Abaeté river will determine flood control, interruption of dourado flux 18 between São Francisco and Abaeté rivers, reduction of lotic stretches to less than the required for keeping dourado populations between reservoirs. 20 In order to dourado conservation, it is recommended: maintenance of Abaeté river, as an important lotic stretch for dourado; inclusion of October on the period of prohibition of 22 fishing; maintainance of abaeté river mouth as a prohibite area for fishery and inclusion of the São Francisco river upstream of Pontal as a priority area for dourado conservation.