Introduction of fish, especially salmonids such as trout, and potentially crayfish is a significant threat that can eradicate populations from a breeding site. In the Montenegrin karst region, populations have declined as ponds created for cattle and human use were abandoned over the last decades. Lack of adequate, undisturbed land habitat (see section Habitats above) and dispersal corridors around and between breeding sites, is another problem.[15]:216[13]:130–144