Vendace and other fresh water fish species

Monitoring the most important vendace lakes

The project is monitoring the development of fresh water fish stocks. The focus is on the monitoring of vendace stocks in 90 Finnish lakes and in the Bothnian Sea.

The goals of the project are to:

- provide information for the planning of fishing;

- enhance the conditions for a successful fish market;

- develop methods for managing of fish waters;

- increase knowledge of the reasons for variation in vendace stocks.

Abundance of vendace a little below average

There have been no significant changes in Finnish vendace stocks in recent years. According to a survey in 2007, the stocks in southern Finland are a little below average, but the stocks in northern Finland are above average. Furthermore, year class in 2006 was at least average for northern Finland. In other parts of the country, spawning stocks in autumn 2006 were smaller than average, and the situation was similar to hatchings in spring 2006. The good state of stocks and catches is still based on three-year-old vendace born in 2004.

Estimating the abundance of year class 2007 stocks more challenging than usual

Time-series analyses for the abundance of vendace in western Finland in 2007 indicates a weaker or equally strong year class as 2001 and 2002. In eastern Finland the year class is probably of average strength. In the lakes of Lapland, the year class has been average for the past three years, so that the next year class will probably be weaker than average.

Fishermen as sources of information

Information about the relative abundance of vendace stocks is collected from over a hundred fishermen and scientists with the help of surveys in the autumn and winter. The abundance of spawning stocks has been mapped since 1988, and young vendace stocks (less than one year old) since 1996. In the most recent survey, the abundance of both the spawning group and year class 2006 was assessed on a scale of 1 to 5, where 1 meant very weak and 5 very abundant stock. The size of young vendace, the composition of catches and the market situation were also assessed in the survey.

More information

The project is proceeding in close cooperation with the Finnish Coregonid Stock Research and Fisheries Network (CORNET) of the University of Jyväskylä.

Scientist in charge of project

Pentti Valkeajärvi
Finnish Game and Fisheries Research Institute
Jyväskylä Game and Fisheries Reserch
Survontie 9
FI-40500 Jyväskylä
Tel. + 358 205 75 514, gsm 040 755 6651
e-mail: firstname.lastname@rktl.fi

Other research staff: Heikki Auvinen, Raimo Riikonen

Duration: continuous

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