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Impacts of climate change and land-use scenarios on Margaritifera margaritifera, an environmental indicator and endangered species

Publication . Santos, R.M.B.; Fernandes, L.F. Sanches; Varandas, Simone; Pereira, Mário Gonzalez; Sousa, R.; Teixeira, Amílcar; Lopes-Lima, Manuel; Cortes, Rui M.V.; Pacheco, F.A.L.

In this study, we assess the impacts of future climate and land-use in the Beça River (northern Portugal) under different scenarios and how this will translate into the conservation status of the endangered pearl mussel Margaritifera margaritifera (Linnaeus, 1758). This species is currently present in several stretches of the Beça River that still hold adequate ecological conditions. However, the species is threatened by projected declines in precipitation for the 21st century, with implication on the river flows and water depths that might decrease below the species requisites. This situation could be especially critical during summer conditions since the ecological flows may not be assured and several river stretches may be converted into stagnant isolated pools. The habitat connectivity will also be affected with reverberating effects on the mobility of Salmo trutta, the host of M. margaritifera, with consequences in the reproduction and recruitment of pearl mussels. In addition, human-related threats mostly associated with the presence of dams and an predicted increases in wildfires in the future. While the presence of dams may decrease even further the connectivity and river flow, with wildfires the major threat will be related to the wash out of burned areas during storms, eventually causing the disappearance of the mussels, especially the juveniles. In view of future climate and land-use change scenarios, conservation strategies are proposed, including the negotiation of ecological flows with the dam promoters, the replanting of riparian vegetation along the water course and the reintroduction of native tree species throughout the catchment.

2015Journal article

Open access

Tartrate stabilisation of Rosé wine using ion exchange resins

Publication . Borges, Rita; Fernandes, Conceição; Marques, Celeste; Matos, Carlos; Vilela, Alice; Nunes, Fernando M.; Cosme, Fernanda

Tartaric stabilisation is essential to satisfy the quality criteria of wines. To prevent wine tartaric precipitates, potassium hydrogen tartrate (KHT) and calcium tartrate (CaT), several techniques can be used. The addition of oenological products, such as metatartaric acid and carboxymetilcelulose (CMC’s) as well as the use of ion exchange resins are acceptable techniques for tartaric stabilization by the OIV, according to Resolution 43/2000. The aim of this study was to evaluate the ion exchange resins effect on wine tartaric stabilization efficiency and wine quality, compared to effect of the addition of different oenological additives. A Rosé wine from 2015 vintage, Douro region, was used for the experiments. Ion exchange resin versus CMC’s, with different structural features (Guise et al. 2014), and metatartaric acid were tested concerning wine tartaric stabilization, physicochemical and sensory characteristics. As expected, all treatments stabilized the Rosé wine. After treatment with ion exchange resins, Rosé wine pH was lower and consequently wine acidity increased. Also, mineral composition (magnesium, calcium, potassium and sodium) decreased after treatment with ion exchange resins. In general, in wines treated with ion exchange resins, there are a decrease in polymeric pigments and colour intensity. Sensory analyses of this wine also showed, for the visual descriptor, colour intensity and limpidity attributes, that they were lesser and higher scored, respectively. Results from this preliminary study suggest that ion exchange resins could be an effective alternative for wine tartaric stabilization.

2018Conference object

Open access