Another research expedition within the frameworks of the “Model river Mezen” project with participation of the Silver Taiga Foundation employees, specialists of the Federal State Institution “Komirybvod” and the Udora district Committee for Environmental Conservation, as well as the representatives of the local community “Udorachi” was carried out.
The main task of the expedition was to monitor the reproduction of the Atlantic salmon (salmon) population, as the most vulnerable fish species, on the spawning grounds. The second task was to analyze the poaching situation, which was determined by the fact that overfishing had been the main reason of the drastic reduction of fish resources in the past decade.
At the beginning of October the weather on the Mezen is cool, with night frosts. The water temperature in the rivers is gradually decreasing from 6 to 2 ° С. Precisely this regime is required for salmon spawning, that’s why exactly during this season the expedition participants went to three different directions. The first group went to explore the upper reaches of the Mezen (from the mouth of the river Uv-Yu to the village Verkhnemezensk) and its tributaries the Upper and the Lower Puzla, the second group went to the river Pyssa, the third one – to the river Yolva. The groups had the task to boat up to the upper reaches of the river – to the place with numerous riffles, because on such areas – with a fast water flow and a pebbled bottom – the salmon is spawning.
For monitoring of the salmon spawning it’s required to evaluate a number of the so called pits and hills. A pit is a hole made by the salmon in order to lay eggs there. Having performed one or several egg layings to the pit, the salmon covers them with a pile of pebbles. It’s called a hill. Sometimes, due to some reasons it leaves a prepared pit and changes the place. Such “trial pits” are also interesting for monitoring.
According to the results of the research the spawning of the salmon has been successful this year. During the expedition more than 150 pits and hills were detected, which is much more than last year. According to the opinion of the specialists, it is related to the high water level, which helped the salmon to get to the upper reaches and to escape the nets and fences of the poachers.
The same as last year, traces of poaching could be seen everywhere. In spite of the fact that due to the high water level in the rivers there was not much direct evidence of fishing – nets, fences, poachers themselves, there were plenty of indirect traces – fire beds, fish traps left on the bank, and net poles.
Currently, the employees of the Foundation are processing the information collected during the expedition. The monitoring will be continued next year. Such researches are necessary for determination of the main reasons of the salmon stock degradation and development of a salmon restoration program on the Mezen jointly with the Arkhangelsk region.