Natural history of Italian freshwater fish has been severely affected by social and economic changes started with the industrial revolution at the end of XIX Century. Since then, the distribution of fish species has undergone deep modifications resulting in a wide reduction of species number, besides alterations in population structures and dynamics. In a recent revision of Cyclostomata and Osteichthyes taxa, 52 different species have been listed in Italian freshwaters. Among them, 6 species were classified DD, 13 LC, 3 NT, 10 VU, 7 EN, 11 CR and 2 RE, considering IUCN categories and parameters. River fragmentation and overexploitation have been the main causes of extinction (RE) for the two anadromous sturgeons Huso huso and Acipenser sturio whose particular reproductive biology is based on homing behaviour and prolonged sexual maturation time. Similarly, Acipenser naccari was classified as critically endangered (CR). Additional 10 other species, mainly belonging to endemic salmonids resulted CR as a consequence of water depletion and massive restocking with non-indigenous strains in alpine and apennine rivers and streams. Despite differences among taxonomic groups and risk categories, population trends are constantly decreasing in all species and several environmental and biological factors threaten species survival over a short-medium time range. Main pressures and threats are referred to extended urban development, habitat alterations of water courses, and consistent water depletion. Additional threats referred to pollution, global warming, birds predation, and alien species introductions are consequences themselves of anthropogenic modifications of land and water exploitation. Among different threats, it must be remarked the unsolved question of invasive species, whose number is constantly increasing. 47 different allochthnous fish have been listed in the recent IUCN revision but results have probably been underestimated due to continuous new arrivals. Future hopes, solutions and improvements are connected to the application of European regulations and directives, such as the Water Framework Directive 2000/60/CE, as a necessary starting point to preserve these important bioindicators of water quality and get rid of the ancient consideration of fish as negligible, unimportant “minor fauna”.
Freshwater fish fauna of italy: emerging problems and conservation perspectives
LORENZONI, Massimo;
2014
Abstract
Natural history of Italian freshwater fish has been severely affected by social and economic changes started with the industrial revolution at the end of XIX Century. Since then, the distribution of fish species has undergone deep modifications resulting in a wide reduction of species number, besides alterations in population structures and dynamics. In a recent revision of Cyclostomata and Osteichthyes taxa, 52 different species have been listed in Italian freshwaters. Among them, 6 species were classified DD, 13 LC, 3 NT, 10 VU, 7 EN, 11 CR and 2 RE, considering IUCN categories and parameters. River fragmentation and overexploitation have been the main causes of extinction (RE) for the two anadromous sturgeons Huso huso and Acipenser sturio whose particular reproductive biology is based on homing behaviour and prolonged sexual maturation time. Similarly, Acipenser naccari was classified as critically endangered (CR). Additional 10 other species, mainly belonging to endemic salmonids resulted CR as a consequence of water depletion and massive restocking with non-indigenous strains in alpine and apennine rivers and streams. Despite differences among taxonomic groups and risk categories, population trends are constantly decreasing in all species and several environmental and biological factors threaten species survival over a short-medium time range. Main pressures and threats are referred to extended urban development, habitat alterations of water courses, and consistent water depletion. Additional threats referred to pollution, global warming, birds predation, and alien species introductions are consequences themselves of anthropogenic modifications of land and water exploitation. Among different threats, it must be remarked the unsolved question of invasive species, whose number is constantly increasing. 47 different allochthnous fish have been listed in the recent IUCN revision but results have probably been underestimated due to continuous new arrivals. Future hopes, solutions and improvements are connected to the application of European regulations and directives, such as the Water Framework Directive 2000/60/CE, as a necessary starting point to preserve these important bioindicators of water quality and get rid of the ancient consideration of fish as negligible, unimportant “minor fauna”.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
