BIOLOGY AND FISHERY VALUE OF ROACH (RUTILUS RUTILUS LINNAEUS, 1758) IN THE LAKES OF THE KENOZERSKY NATIONAL PARK
A roach is an Eurasian species with a very wide range. In our waters it is represented by the subspecies R. rutilus rutilus (L., 1758), a common roach. Lake-river schooling fish is widely distributed in the water bodies of the Arkhangelsk region. On the territory of the Kenozersky National Park (KNP), it is found in almost all studied reservoirs, with the exception of bog lakes. Roach is one of the most numerous fish. Along with perch, it is part of the so-called core of almost all lake ichthyocenoses national park. Being an environmentally flexible species roach adapts to different environments. In unfavourable conditions the roach sharply slows down the growth rate, but does not reduce its numbers. In the KNP it is of great fishery value. Its share in the total catch of commercial fish species in Park waters is 9-9,5 %. During the spawning season this species is one of the main objects of recreational fishing in the national park. The study of the biology and ecology of roach is nowadays of particular interest due to the changes occurring in the ichthyofauna of the Kenozersky National Park. The increase in the number of carp fish species (including roach) in the reservoirs of the Park is probably due to global climate change.