SEH grant 2018

Conservation of Pyrenean newts: interlake dispersal & colonisation dynamic (Calotriton asper)

High mountain lakes are naturally fishless, as their glacial origin has kept them isolated from lower streams, preventing natural colonisation by fishes. Globally, however, over time many of these lakes have been stocked with fish in an attempt to create recreational fishing. Invasive fish are known to be one of the main drivers of reduction or extinction of autochthonous amphibians in high mountain lakes. Calotriton asper is an amphibian endemic to the Pyrenees, listed as Near Threatened by the IUCN. We aim to investigate C. asper patterns of colonisation of new ecosystems following fish removal and the process of migration from nearby lakes and streams, by means of genetic and field-based approaches. The study site is located in an area of recent colonisation in the National Park of Aigüestortes i Estany de Sant Maurici, in the central-eastern Pyrenees. Assessment of genetic diversity and population structure will be conducted through the analysis of 20 nuclear microsatellite markers. C. asper individual photo-identification will be performed, based on its variegate ventral pattern. The two methodologies will be combined to describe patterns of migration between lakes and evaluate the effect of habitat fragmentation induced by invasive fish.