Under Action A3 of the LIFE Saramugo project, an update was made on the population status of saramugo in the Guadiana river basin. To this end, in the spring of 2015, the project teams sampled the ichthyofauna at 45 sampling stations, in accordance with the sampling protocol established by the National Water Authority, within the Water Framework Directive (WFD).
The application of this sampling methodology made it possible to calculate the normative index, the F-IBIP (Índice Piscícola de Integridade Biótica para Rios Vadeáveis de Portugal Continental). This index is based on a fish typology for Portugal, with different fish groupings, and the sampling stations carried out in this study were classified into two groups: i) 4 - Small-sized Ciprinícola of the Northern and Southern Regions; Ii.) And 5 - Medium-sized Ciprinícola of the Southern Region.
Like other indexes of biotic integrity, the F-IBIP is constituted by several metrics that try to reflect basic structural and functional characteristics of the different fish groups. As a result, the F-IBIP varies from 0, corresponding to poor quality, and 1, corresponding to excellent quality (see table 1). There is also a division into five ecological quality classes according to the WFD assumptions.
From the work developed, it was verified that the southernmost streams (Foupana, Odeleite and Vascão) presented, generally, a Good or Excellent quality, resulting from the absence or residual presence of exotic specimens, associated with the expressive percentage of specimens that feed of invertebrates. Similar situation is verified in the Murtega and Álamo streams, as well as in the upper sector of the Caia rivers (including the Arronches stream) and Chança.
The terminal sector of the Chança river, the Ardila basin (streams of Safarejo and Murtigão) and the stations downstream of the Foupana and Vascão streams were classified in the Reasonable class. This classification results from the fish communities presenting intrusion of exotic species and / or decrease of invertivorous specimens, in addition to the absence of some intolerant cyprinid species.
Regarding the Xévora basin and the Pardiela, Lucefécit and Carreiras streams, the strong presence of exotic species and the concomitant absence / residual presence of native cyprinids justified the classification in Mediocre or Bad state.
Generally there was a coincidence between fluvial sectors in Good or Excellent state and the presence of saramugo, particularly in the Chança rivers (upper sector), Foupana, Odeleite and Vascão. Saramugo was also identified in the rivers of Murtigão and Safareja (basin of the Ardila) as well as in the lower section of the Chança river, these stations being classified in the class Reasonable.
In the last year of the LIFE Saramugo project, the monitoring and calculation of the F-IBIP will be repeated in the sub-basins where actions to improve and / or recover the saramugo habitat have been carried out. In this way it will be possible to gauge the evolution of the fish communities and indirectly to evaluate the effectiveness of the beneficiation actions carried out within the scope of the project.
