The study of Lake Burtnieks ecosystem and management strategy development


Lake Burtnieks is the 4th biggest lake in Latvia. Around 70% of all freshwater contained by the River Salaca – the “backbone” of the North Vidzeme Biosphere Reserve (UNESCO The Man and the Biosphere Programme site) and one of a few natural salmon rivers in Europe – comes from Lake Burtnieks. The lake is known for its abundant fish resources and large role in local economy. However, the ecological condition of the lake is unfavorable. As a result of human activities such as dredging of the River Salaca, building of a land reclamation dam, pollution from agricultural and forestry activities, waste waters from municipalities, selective commercial and recreational fishing, the lake’s shores have overgrown with reeds and bushes, the food web has been disbalanced, and there are regular cyanobacterial blooms during the summer months. The attractiveness and accessibility of Lake Burtnieks is rapidly decreasing.

The Aim

To develop a strategy for the integrated and sustainable management of Lake Burtnieks in order to foster the recovery of lake’s ecosystem and the socio-economic development of its adjacent territories.

Our Role

IES is the principal contractor.


The study of Lake Burtniek’s ecosystem is based on classical hydrobiological research methods – sampling and analysis of nutrients, phytoplankton, zooplankton, and zoobenthos as well as hydro botanical surveys using airborne RGB and hyperspectral remote sensing and ground-truthing. Fish surveys were performed according to the EU standard EN 14757:2005 using Nordic type multimesh gillnets, electrical fishing and a pelagic fishing trawler.  The latter was carried out in cooperation with the Biology Centre of the Academy of Sciences of the Czech Republic.

The 2013 season results indicated the presence of large amounts of nutrients in the water of Lake Burtnieks which is one of the factors contributing to the continuous deterioration of the water quality. The research of the 2014 resulted with the quantitative data of fish communities survey using innovative field research methods; detailed vegetation measurements by using high resolution airborne remote sensing system ARSENAL; a mathematical model for the prediction of possible effects of different management measures on the quality of Lake Burtnieks ecosystem. The three-year study will end in 2015, and the researchers’ findings will serve as the basis for the development of Lake Burtnieks management strategy.

Project duration: 01.05.2013 – 20.12.2014

Project coordinator: Leading Researcher Dr.biol. Matīss Žagars, e-mail:, telephone : +37164127951

Project funded by: Burtnieki local municipality

Co-funded by: Institute for Environmental Solutions

Project collaboration partners: the Biology Centre of the Academy of Sciences of the Czech Republic, Finnish Environment Institute (SYKE)