Strategies for Mitigating the Impact of Hydropower Plants on the Stocks of Diadromous Species in the Daugava River

The Daugava River is the largest river in Latvia. Daugava Hydro Power Plants 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 diadromous species. Compensatory stocking activities are introduced annually. The need for studying alternative or additional impact mitigation measures is based on biodiversity conservation aspects and possible changes in EU legislation. The case study of solutions for improving the Daugava River connectivity is introduced and further strategies for mitigating the impact of HPP are proposed in the paper.