The Vez river - Planning and sustainable management of the fish specie (Salmo trutta)

The study took place at the Vez River that belongs to the Lima River basin and Minho and Lima region basin located in the municipality of Arcos de Valdevez. Due to its diversity of habitat and species that shelter the Vez River area were classified as Site of Community Importance (SCI) for the Conservation. The aim of this work were conducting inventory and characterization of the fish population, the ecological characterization of the sampling sites and the implementation of a set of actions that will help improve the protection, management and planning of activities, with particular reference to sport fishing. Fieldwork was conducted in two phases (March / April and June) and it was studied a total of 16 sampling sections of the river from the source to the mouth. We proceeded to sampling of the fish species populations with electrofishing. In this context was carried out to analyze the data regarding the age, growth, physical condition and fitness or coefficient ("K" factor) of the captured specimens. The results confirmed that we are facing a river course with a wide variety of habitats, which seems to have low rates of artificialization. The Salmo trutta, Anguilla anguilla and Chondrostoma polylepis fish species represents the most euribiontes at this river. In this sense, it appears that that Vez River has Salmo trutta almost from source to its confluence with the Lima River. The Squalius carolitertii is dominant in the middle course of the river followed by Achondrostoma arcasii and Barbus bocagei. In the last two sections (15 and 16) further downstream close to the mouth of the river, it was relevant the capture of some specimens of juvenile Petromyzon marinus and Salmo trutta trutta. No exotic species were found. For the entire sample of 16 sections Salmo trutta presents an isometric growth and shows a slight lack of robustness.