New report confirms the endangered status of the endemic Prespa trout

In June 2020, PONT and CEPF awarded a grant to the Balkan Foundation for Sustainable Development in North Macedonia concerning the conservation of the endemic Prespa trout (Salmo peristericus) which is listed as Endangered on the global IUCN Red List. Brajchinska and Kranska rivers support the largest populations of this species in North Macedonia, while a small population is found in Leva River, all within the Lake Prespa watershed. This species also inhabits the Agios Germanos river in the Greek part of Prespa.

The initial grant activities focused on re-assessing the conservation status of the Prespa trout, taking into account the previous studies conducted before the construction of three hydropower plants on Brajchinska and Kranska rivers in 2013 and 2014.

Using the standard fish sampling method (CEN 2003), a total of 413 fish of the Prespa trout were collected at 27 sampling points along Brajchinska, Kranska and Leva rivers to determine the spatial distribution, density, sex and length structure of the populations, as well as the time and length of first sexual maturation, length-weight ratio and coefficient of condition.

The established coefficient of condition and length-weight relationship indicate that the Prespa trout fish in the surveyed rivers have long slender bodies and low body weight. Sexually mature males were registered already in the length class of 8.1 – 9 cm and all fish over 14 cm in length were sexually mature and capable of reproduction; the largest fish caught were 27.7 cm in length.

The survey established that water intakes of the small hydropower plants at Brajchinska and Kranska rivers present additional barriers for migration of the Prespa trout. In combination with the lack of longitudinal connectivity of the watercourses (downstream and upstream), these barriers aggravate the fragmentation and isolation of the Prespa trout populations.

Due to the current threats, spatial distribution, population size and decreasing tendency, the Prespa trout continues to meet the criteria for listing in the Endangered category, according to the IUCN Red List Categories and Criteria.

The results of this latest assessment are presented in a report available in English and Macedonian. This report will inform the development of a conservation action plan for the Prespa trout in North Macedonia, in consultation with key stakeholders, including the Ministry of Environment and Physical Planning, the Ministry of Agriculture, Forestry and Water Economy, Municipality of Resen, Public Institution Pelister National Park, National Forest Service, hydro power plant operators, local communities and local civil society organisations.