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Browsing CIMO by Sustainable Development Goals (SDG) "14:Proteger a Vida Marinha"
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- Interspecific differences in the physiological condition of native freshwater mussels in response to the invasive Asian clam Corbicula flumineaPublication . Modesto, Vanessa; Ilarri, Martina; Castro, Paulo S.; Carvalho, Francisco; Cavalheri, Thais; Lopes-Lima, Manuel; Teixeira, Amílcar; Ozório, Rodrigo O.A.; Antunes, Carlos; Sousa, RonaldoThe Asian clam Corbicula fluminea has been widely introduced into aquatic ecosystems and may impact the physiological condition and survival of native freshwater mussels. However, very few studies have evaluated this issue quantitatively. To fill this gap, manipulative field experiments were performed to assess two possible mechanisms of impact on native mussels: (i) interspecific interactions, and (ii) C. fluminea die-offs. We assessed these effects by measuring the physiological condition through the analysis of glycogen content in the foot tissue of the native freshwater mussel species Anodonta anatina, Potomida littoralis, and Unio delphinus. Although with interspecific differences, our results suggest that C. fluminea can impact the physiological condition of native freshwater mussels. Anodonta anatina showed positive significant variations on glycogen content when subjected to high densities of live C. fluminea in contrast to the other native species studied, P. littoralis and U. delphinus, where no significances were observed. On the other hand, these native species do not seem be significantly impacted by the decomposition of C. fluminea resulting from a die-off. Overall, and contrary to our expectations, both experiments showed a positive (or no) effect of C. fluminea on the physiological condition of the three freshwater mussel species.
- Invasive dynamics of the signal crayfish Pacifastacus leniusculus in a protected areaPublication . Carvalho, Francisco; Alves, Henrique; Pascoal, Cláudia; Castro, Paulo; Miranda, Fernando Jorge Veloso; Teixeira, Amílcar; Cássio, Fernanda; Sousa, RonaldoInvasive species have been drivers of biodiversity loss and functional changes in aquatic ecosystems, including in protected areas. Therefore, monitoring population invasion dynamics and biological traits is fundamental to better understand their ecological and economic impacts and for management actions development. We followed signal crayfish (Pacifastacus leniusculus) invasion in Rabaçal River upper reach at Montesinho Natural Park, Portugal. We collected information on the spread and biological traits (abundance, size, weight, physical condition, sex ratio, and aggressiveness) to assess differences between invasion core and front areas and among years. Signal crayfish population remained restricted since first reports in 2013 in the invasion core until 2017. After 2019, signal crayfish population has been spreading downstream, decreasing abundance at invasion core but increasing at invasion front. Significant higher number of crayfish with claw loss indicate potential higher signs of aggressiveness in the invasion front. Results also demonstrate a significant dominance of females although sex ratio is closer to 1:1 at the invasion front. Overall, results indicate signal crayfish is spreading and increasing their abundance at Rabaçal River highlighting the need for immediate management actions to hold dispersion and mitigate possible impacts.