Тhe second Аmur complex ichthyological expedition – prerequisites and first results

In 2018–2019 the second Amur ichthyological expedition has been prepared and is being conducted since 2020. The impetus for its organization was a sharp drop in the catches of Pacific salmons in the basin of the Amur River in 2017 and 2018, when after the maximum catch in 2016 (65,2 thousand tons), their catch decreased to 26,9 and 21,6 thousand tons, respectively. This required the adoption of urgent management decisions to preserve their reserves, as well as the expansion of the study of the Amur aquatic biological resources. The expedition has a complex character; the research covers the channel and accessory system of the middle and lower Amur, as well as Khanka Lake. Totally completed: about 5 thousand stations, more than 1,1 thousand hydrobiological samples were taken, about 40 thousand fish were subjected to bioanalysis. New data on the biology of Pacific salmon, smelts, freshwater and sturgeon fish species have been obtained and partially published (70 papers). A number of modern innovative research methods have also been introduced (the use of UAVs and GIS systems to account for Pacific salmon spawners, microchemical analysis of otoliths to assess the effectiveness of their artificial reproduction). The results obtained are of wide practical importance: they are used in the development of measures to regulate the fishing of various aquatic biological resources, including when amending the Fishing Rules.