Telemetry study for reintroducing wild Atlantic salmon (Salmo salar L.) in the Daugava and Ogre River, Latvia
The Daugava River is the largest river in Latvia. It flows through Russia, Belarus, Latvia and empties into the Gulf of Riga, in the Baltic Sea. Three Daugava hydro power plants (HPP) built in 1939 – 1974 are Latvia’s most important renewable resource in generation of electricity. The absence of fish passage structures excludes upstream migration of Atlantic salmon and other fish species. Compensatory stocking activities are realized annually.
Aim
To investigate the possibilities of reintroducing Atlantic salmon (L.Salmo salar) population in the Daugava River ecosystem.
Our solutions
To investigate the behaviour and migration habits of Atlantic salmon, we carried out a telemetry study with trap- and transport- approach. Eighteen Atlantic salmons were caught near the river mouth of the Daugava River and tagged. Two groups were transported past the most downstream obstacle in the Ogre River to two different release sites and a third group was released in Riga reservoir, above Riga HPP, in the Daugava River. Adult salmon transported in the Ogre River did not migrate upstream, but instead they moved downstream to the Daugava River, probable due to flooding. The study also showed that downstream passage of both Ogre HPP and Riga HPP was possible. In addition, using questionnaires we researched the Ogre Municipality locals’ willingness to pay for salmon reintroduction activities. Overall results showed that they are willing to pay certain amount of money per year.
The information obtained may serve as valuable resource for the future activities of reintroducing the wild Atlantic salmon in Daugava.
Publication poster: A telemetry study for reintroducing wild Atlantic salmon (Salmo salar L.) in the Daugava and Ogre Rivers, Latvia
Project duration: 2013. – 2015.
Project Manager: Dr.biol. Matīss Žagars, E-mail: matiss.zagars@videsinstituts.lv, tālr. 29218057
Project financed by: JSC “Latvenergo”
Project partners: Institute of Food Safety, Animal Health and Environment “BIOR”, Karlstad University, Polytechnic University of Turin
