On the Diversity of Fish Population in the Mezen River

Model River Mezen Working Group is appealing to the public to report any cases of new unrepresentative fish species found in the catchment.

Rational management of any resource implies continuous collection of data on its condition, or monitoring. Unfortunately, monitoring of the fish population in the Mezen river is far from being sufficient due to a number of reasons, including shortage of funds, lack of people, and others. Theoretically, you need to assess quality and quantity indicators, such as species composition of the fish community in each water body, population size of each species, migration patterns, age-sex pattern of each species, infestation intensity and extensity. It is absolutely necessary to monitor the condition and accessibility of spawning grounds for various species with various needs, since some of them want drowned plants and slow water flow, others need shingle and strong flow, and so on.  The food potential and negative environmental impact on aquatic ecosystems are also relevant to be estimated. All in all, it is evident that such a short list of actions required implies high costs, which can only get paid back at frequently visited fishery plots.

The river’s species composition is not constant – from time to time some species disappear for reasons attributable to human activity or natural causes, while other species settle in the river. The Mezen river accounts for 31 species from 14 fish and fish-like vertebrate families, with 15 species out of them being registered to inhabit the upper reach (upstream the village of Ust-Kym). 7 other species were recorded based on the evidence from fishermen or other sources.

The complete list of the Mezen river fish species is given in the table below.

‘+’ – the species is recorded in the upper reach of the Mezen river

‘–’ – the species is not recorded in the upper reach of the Mezen river

‘?’ – the species are mentioned to be noticed in the upper reach of the Mezen river

Occasionally, we find information about new species caught in the Mezen. For instance, we have been told this year that bull-trout was found in the middle reaches of the Mezen. Some species like humpback salmon got into the river from the sea, others may have been let out there by aquarians, which is considered illegal introduction; in addition there are other ways to get into the river.

We invite you to inform us, if you happen to learn about any cases of catching untypical species in the Mezen. It will be especially useful for us to get the following data: date and time of the catchment, exact location (GPS coordinates are welcome), fishing gear, fish size and weight, hard or soft roe present, pictures attached. It is extremely desirable for you to state your contact details in case we want to check up on the information.