Ir a canal FaceBook de CONAMA
Ir a canal Twitter de CONAMA
Ir a canal LinkedIn de CONAMA
Ir a canal YouTube de CONAMA

Fish Passes Established in the Segura River Basin: Fish-based assessment and preliminary data

Autor: Ana Sánchez Pérez
Universidad de Murcia
Otros autores: Francisco José Oliva-Paterna, José Manuel Zamora-Marín, Antonio Zamora-López, Fátima Amat-Trigo, José María Franco & Mar Torralva (Universidad de Murcia)
Tipo: Comunicación técnica escrita
Temática: Biodiversidad; Ecodiseño y análisis de ciclo de vida
Documentos asociados: Doc. Escrito
Resumen:
The LIFE+ Segura-Riverlink is a project which aims to validate management measures for the development of a Green Infrastructure (GI) approach into the context of Mediterranean river basins characterized by high impacts. The project will recover the longitudinal connectivity in a sector of 54 km long in the Segura River implementing fish passes over several artificial barriers to improve and restore fish movements and will also support other best practices of riverine restoration. Since September 2015, five fish passes, natural-like fishways and technical fishways have been implemented.

A monitoring programme evaluates the performance of these actions with the hope of validating the GI approach to river basin management. Two main fish-based assessments have been developed to reach the aims of the monitoring: one focused on the fish population use of fish passes (1), and a specified mark-recapture program of sentinel species (2). In the present study, we briefly describe the monitoring methods and the preliminary results.

Since January to July 2016, a total of 2973 individuals of 8 fish species were collected inside fishways. Target species which are characterized by reproductive seasonal movements accounted for 98% of the total abundance, Alburnus alburnus (47,2%), Gobio lozanoi (31,3%), Luciobarbus sclateri (11,1%) and Pseudochondrotoma polylepis (8,5%). Most captures were detected in two fish passes, 56% in a vertical-slot fishway, and 18% in the natural-like fishway.

In the specified mark-recapture program, a total of 695 individuals of L. sclateri were marked by ANCHOR-Tags. Moreover, a total of 735 specimens have been marked (4 target species) by VIE-tags, 53,3% inside the fish passes and 46,7% outside in their next down-stream stretches. The rate of recaptures inside the passes was 17,6%, and 5,9% for 2nd recaptures, both greater in nature-like fishways. G. lozanoi was the dominant species in recaptures (50,9%), and L. sclateri the second one (19,9%). Only 6,3% of recaptures inside the passes was originating from specimens marked down-stream.

The evaluation by mark-recapture programme shows that the fishways are being occupied by different species, most of the species detected in the studied fluvial sector use the different types of fishways aimed in this survey.