Freshwater crayfish in South Tyrol (Italy): Distribution and protection measures of endangered Austropotamobius pallipes

Abstract

Freshwater crayfish are among the most endangered animals in Europe. Information on freshwater crayfish in the Italian province of South Tyrol was insufficient until the recent studies on their historical and present distribution, which showed the alarming facts that only 15 standing and running waters remained as freshwater crayfish habitats, carrying the native Austropotamobius pallipes and the allochthonous Astacus astacus, Orconectes limosus, and Pacifastacus leniusculus. Still ongoing alterations or degradation of water bodies have contributed to the high degree of population decline and loss. While the exotic crayfish O. limosus and P. leniusculus could develop higher densities, most of the autochthonous A. pallipes populations were weak and consisted only of a few individuals. Three populations of A. pallipes, however, remained in a good condition, representing potential sources for recovery programs. Protection measures currently carried out in South Tyrol involve breeding, restocking and reintroduction of autochthonous A. pallipes individuals in ecological intact water bodies.