A tale of shells and claws: The signal crayfish as a threat to the pearl mussel Margaritifera margaritifera in Europe

Abstract

We assessed the predation of crayfishes on freshwater pearl mussels. • In the laboratory, predation of freshwater pearl mussels was size dependent. • In the field, predation of freshwater pearl mussels was density dependent. • Invasive crayfishes may impair the conservation of freshwater pearl mussels.

Combining geostatistical and biotic interaction model to predict amphibian refuges under crayfish invasion across dendritic stream networks

“…stream orders 1 and 2; Finn, Bonada, Múrria, & Hughes, ) represent key refuges from crayfish invasion for many amphibian species, as these streams dry out for more or less extended periods during the dry season (Ferreira et al, ) and are thus expected to remain largely free from crayfish impacts (Cruz & Rebelo, ; Filipe et al, ). Overall, our study reinforces the conservation importance of stream headwaters in the Mediterranean region, which are increasingly perceived to play key roles as refuges from biological invasions and other human‐mediated disturbances, both for amphibians (de Vries & Marco, ) and other vulnerable species (Quaglietta et al, ; Sousa et al, ). Our approach may be applied to other aquatic species, with major implications for conservation and management by permitting a better identification of areas acting as ecological refuges under biological invasion.…”

From the lab to the river: Determination of ecological hosts of Anodonta anatina

“…The landscape includes plateaux, mountains, and embedded valleys, with different land uses such as industry, urban development, agriculture, and forestry. The Corgo, Tua, and Tâmega rivers are subjected to higher levels of human disturbance, mainly by pollution from the surrounding industries and urban areas, compared with the Sabor and Paiva rivers(Meira et al, 2019;Sousa et al, 2013Sousa et al, , 2019;…”

Effects of an extreme drought on the endangered pearl mussel Margaritifera margaritifera: a before/after assessment

“…Given the complex life cycle, low dispersal capacity, the restricted ecological niche and the existence of other environmental stressors (invasive species; Sousa et al, 2019), this species, in addition to the apparent low resistance to climatic extremes, also seems to have very low resilience. This means that both populations could take years to recover or not recover at all.…”

“…The three sampled rivers have a very low human pressure and are highly forested (mainly Quercus spp.) being considered an important habitat for threatened aquatic species such as pearl mussels M. margaritifera (Endangered), water desman Galemys pyrenaicus (Vulnerable) and Iberian loach Cobitis calderoni (Endangered) (Sousa et al, 2015(Sousa et al, , 2019. Despite the lower human disturbance, the three rivers have been threatened in the last decade by flow modification (dams and weirs), the introduction of non-native species (Sousa et al, 2019) and increasing occurrence of extreme climatic events such as floods and droughts (Sousa et al, 2012(Sousa et al, , 2018.…”

“…The pearl mussel Margaritifera margaritifera (Linnaeus, 1758) is one of the freshwater mussel species with highest conservation importance, and the number of ecological studies and applied conservation programmes increased substantially in the last two decades (Geist, 2010;Lopes-Lima et al, 2017;Sousa et al, 2019). This species is one of the most threatened bivalves in Europe being classified as Endangered (Critically Endangered in Europe) by the IUCN, and protected by the European Union under annexes II and V of the European Commission Habitats Directive [92/43/EEC].…”