Browsing by Author "Inssi, Hanane"
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- Bioecology and conservation of Duck Mussel Species (Anodonta anatina L., 1758) in Northeastern PortugalPublication . Inssi, Hanane; Teixeira, Amílcar; Berday, NadiaFreshwater mussel (Mollusca, Bivalvia, Unionoida) populations are one of the most endangered faunistic groups. Mussels play an important role in the functioning of aquatic ecosystems, because they are responsible for the filtration and purification of water. They have a complex life cycle, with a parasitic larvae and usually limited host fish species. The real status of these populations is still poorly understood worldwide. The objectives of the present work were the study of bioecology of duck mussel (Anodonta anatina L.) populations of Tua Basin (NE Portugal). It was made the characterization of the ecological status of Rabaçal, Tuela and Tua Rivers, selecting 15 sampling sites, equally distributed by the three rivers. Samplings were made in the winter of 2016, and several physico-chemical water parameters measured and two habitat quality indexes calculated (GQC and QBR indexes). Benthic macroinvertebrate communities were sampled based on the protocols established by the Water Framework Directive. Host fish populations for duck mussel were determined in laboratorial conditions, testing several native and exotic fish species. The results showed that several water quality variables (e.g. dissolved oxygen, conductivity, pH, total dissolved solids, and nutrients) can be used for the classification of river typology. Other responsive metrics were also determined to identify environmental degradation. For instances, hydromorphological conditions (GQC and QBR indexes) and biota related metrics (e.g. composition, distribution, abundance, diversity of invertebrate communities) contributed to the evaluation of the ecological integrity. The upper zones of Rabaçal and Tuela rivers were classified with excellent and good ecological integrity, while less quality was found in downstream zones. The host fish tests showed that only native species are effective hosts, essential for the conservation purposes of this mussel species. Threats, like pollution, sedimentation and river regularization (3 big dams are in construction or in filling phase), are the main cause of habitat loss for native mussel and fish populations in the future. Rehabilitation and mitigation measures are essential for these lotic ecosystems in order to preserve the prioritary habitats and the native species heavily threatened.
- Threatened fish and mussel populations in Douro basin (Northern Portugal): in-situ and ex-situ conservation measuresPublication . Teixeira, Amilcar; Froufe, Elsa; Varandas, Simone; Sousa, Ronaldo; Miranda, Fernando Jorge Veloso; Inssi, Hanane; Lopes-Lima, ManuelFreshwater 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.