Author(s): Teixeira, Amilcar ; Froufe, Elsa ; Varandas, Simone ; Sousa, Ronaldo ; Miranda, Fernando Jorge Veloso ; Inssi, Hanane ; Lopes-Lima, Manuel
Date: 2017
Persistent ID: http://hdl.handle.net/10198/21901
Origin: Biblioteca Digital do IPB
Subject(s): Bivalves; Fishes; Conservation; Threats; Impacts
Freshwater ecosystems are threatened by human activities and their biodiversity declines far greater than those on marine and terrestrial ecosystems. Severa! impacts such as habitat loss and fragmentation, pollution, river regulation, overexploitation, introduction ofinvasive species and envoronmental changes are responsible for increasing the extinction risk ofnative species and for the dismption of important ecosystem functions and services. Freshwater mussels (Bivalvia: Unionoida) are among the most threatened faunistic groups in these freshwater ecosystems. These mussels depend on fish to complete their life cycle, where mussel larvae use a specific range of fish hosts to metamorphose. Therefore, the persistence of freshwater mussel species will ultimately depend on the conservation oftheir físh hosts. The Iberian Península holds a high levei ofspatially restricted species and endemisms. Many native físh and mussel species oflberia are listed as vulnerable, endangered or critically endangered and their populations are declining. In this study, we will use data collected in the last 5 years in the main tributaries ofRiver Douro in Portugal to assess the conservation status of native freshwater mussel and fish species and, in particular, the impact of environmental changes. Despite the low human density in three basins (Sabor, Tâmega and Tua), some river stretches are suffering of habitat loss and degradation. Furthermore, the increase in intensity and magnitude of extreme climatic events are inducing higher mortality rates in fish and mussel populations. There are reports of massive die-offs of mussel populations due to a succession of irregular drought and fíood events. For ali these reasons, several in-situ and ex-situ conservation measures have been developed to protect endangered native species ofNE Portugal. In addition, other actions were oriented to the training and public awareness for the conservation ofthreatened species and habitais.
