Fish and fishing in Lake Peipsi (Estonia/Russia) since 1851: Similarities and differences between historical and modern times

Abstract

The first survey data on the fisheries in Lake Peipsi were collected by natural scientist Karl Ernst von Baer as a result of the world's first special fishery expedition in 1851–1852. In the current study, all available numerical datasets on fishing in Lake Peipsi from 1851 to 2018 have been drawn together in order to analyse the long-term changes in the lake’s fish assemblages. As the study indicates, the overexploitation, catching of juvenile fish and predator–prey imbalance have been common problems associated with fisheries in Lake Peipsi for the last two centuries. Similar to many inland waterbodies worldwide, total catch of fish from Lake Peipsi has decreased about four times since the mid-19th century, and the catch of lake (dwarf) smelt, a previously dominant species, has periodically fluctuated with long-term gradual reduction. The decline of cool-water fish, such as vendace, burbot and Peipsi whitefish during the last two centuries, and the domination of Eurasian perch, common bream and pike-perch in the catches of the last 20 years mark considerable structural shifts in fish assemblages. Of the multiple stressors (e.g., nutrient enrichment, increased water temperature, overfishing) triggering shifts in fish assemblages, the impact of climate warming, especially extreme weather events such as heatwaves, seems to be the strongest during the last three decades. However, none of the fish species have completely disappeared from the lake during the last century although the share of cool-water fish in the total catch has declined about tenfold since the 1930s.