Multiyear roach yield dynamics and its biological characteristics have been researched. The main reasons of roach catch decrease in the Selenginsk fishing area of Baikal Lake have been shown. Among them: low fishing intensity, excessive meshing of fishing gear, shallow overgrowing, water level fluctuations. Fishing statistics for 1970–2011 is shown, as well as dynamics of roach average biological rates in yields and dynamics of growth rates. Quantity and biomass of fishing part of the roach stock and yield rates has been indicated. Optimal mesh size of fishing gear for more efficient fishing has been calculated.