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Mountain environment protects endangered fish

08.11.2017

An endangered species of trout is returning from the brink of extinction in the mountains of the Monti Sibillini National Park. The Salmo macrostigma, or Mediterranean brown trout, is an autochthonous trout found in central and southern Italy. The reasons for this trout becoming endangered were two-fold: water management in terms of water removed for human purposes (water abstraction) and competition with other non-native trout species such as the Atlantic brown trout, which for years has been used for restocking, usually for sport fishing, and with time this trout altered the genetic makeup of the others. LifeTrout, a European Commission project to save the Mediterranean brown trout from extinction, began in 2013 and will end in January 2018.

In order to find the last few indigenous Mediterranean brown trout, researchers went to remote and difficult-to-access places. Most of these sites were located in mountains. The aim of the LifeTrout project was the recovery and conservation of existing macrostigma trout populations in four main watercourses in Central Italy, two of which were located in the Monti Sibillini National Park: the rivers Ambro-Tenna and Nera. Management strategies were developed in these locations, and the last, small populations of autochthonous trout were identified and studied.

Scientists spawned Mediterranean brown trout in captivity. The fish bred during the 2016-2017 season were then moved from laboratory incubators to outdoor vats. Fifty trout were fitted with microchips for research. Meanwhile, a key action for the survival of the Mediterranean brown trout was the removal of the Atlantic trout from the four rivers identified in the LifeTrout project. Monitoring between March and July 2017 revealed there were 60-80 percent less Atlantic trout in the project’s rivers. Likewise, during 2016 and 2017, some 13 500 native trout took to the water for the first time in the project sites.

Once the population of alien Atlantic trout was reduced, the endangered trout seemed able to make a rapid recovery. The project also succeeded in creating new laws that ensure genetic checks on all trout introduced into regional bodies of water and in stabilizing special protection areas to be ‘genetic shelters’ to ensure the indigenous trout population continues.

Alessandro Rossetti, a leading conservation officer at the Monti Sibillini National Park, commented, “LifeTrout has had a strong positive impact on a species of European community interest. Approximately 25 people were involved in the project, along with collaboration with the Carabinieri Forestali.”

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News by Tamara Griffiths

Photo by Alessandro Rossetti