Results of the researches in 2014

In 2014 the research focus of KarRC specialists (project experts in biology) was Syskyanjoki River that is inhabited by 2 Red Book species – landlocked salmon and freshwater pearl mussel. It was known earlier that the part of a river mouth located upstream the abandoned dam is a spawning and nursery site for salmon where spawning of salmon migrating from Ladoga takes place. Alevins inhabit this area during 2-3 years. Colonies and individuals of freshwater pearl mussel were also found in this area. The updated data show that freshwater pearl mussel is widely spread along the river like bull trout. These 2 species are found on main long length rapids.

Several habitat areas of freshwater pearl mussel were found and researched in Syskyanjoki River during the study of the river. The data on the size structure and abundance of the mollusc were also received. Infection and survival rates of glochidia on the gills of juvenile Atlantic salmon were studied.

For the first time the report presented below gives the assessment of the locations and areas of spawning and nursery sites, defines the distribution and its density of alevins and bull trout, identifies salmon stock in Syskyanjoki River.

«Scientific substantination of the establishment of the faunal area “Syskyanjoki” for the preservation of Atlantic salmon, bull trout  and freshwater pearl mussel»  (IN RUSSIAN)

Freshwater salmon of Ladoga Lake is listed in the Red Book what was caused by the decrease of the size and quality of the areas for its reproduction due to anthropogenic influence. Some of the spawning and nursery areas disappeared at all. Rivers, rapids and habitats of the salmons has been changing for a long time. The construction of factories and power plants has changed flow regimes and water levels in the rivers of Priladozhje. Today the construction of several new power plants is planned or is already being conducted. Land utilization in catchment areas, excess fishing and change of the water quality in rivers the salmon stock in the lake decreased. Salmon has almost extinct in some rivers running into the Ladoga Lake.

Finnish experts Esa Laajala and Stepan Lappo (ELY-Keskus, Oulu) has conducted the researches and topographic mapping of 2 rivers in Pitkjaranta district during summer 2014. They studied 2 parts of the Syskyanjoki and Tulemajoki rivers with further creation of 3D models and plans on restoration of the given areas. These rehabilitation measures are aimed at making these areas more attractive for the salmons migrating from the Ladoga Lake for spawning. It is planned to be implemented through making the river bottom more natural like it used to be before the human interference (changes caused by timber floating, construction of power plants, etc.).