Species composition and distribution of fishes at the shallow waters of the low and middle Amur river in summer, 2018 and 2019

Based on the data of seine surveys (June 2018 and 2019, 57 and 38 catches), species composition and structure of fish communities of the middle and low Amur River were studied. The species richness of fish in the low Amur River is higher compared to the middle Amur River, 37 and 22 species, respectively. Upstream of the Amur River, fish biomass falls. At the beginning of summer, its average value in the low Amur was equal 1,354±0,209 g/m2, in the middle Amur – 0,324±0,058 g/m2. In the middle Amur River, the fish biomass was dominated by Hemiculter spp. (29,1%), Opsariichthys bidens (28,0%), Leuciscus waleckii (22,1%), Squalidus spp. (7,5%) and Tachysurus sinensis (3,9%). In the catches on the low Amur River, the fish biomass was dominated by Hemiculter spp. (26,2%), Leuciscus waleckii (21,0%), Hypomesus olidus (18,1%), Rhynchocypris lagowskii (7,6%), Carassius gibelio (7,2%), Rhodeus sericeus (5,0%) and Xenocypris macrolepis (4,6%). Local maxima of fish abundance were determined by the ecological preferences of most common fish species (in particular, their reopreferendum).