Results of quantitative counting for downstream juveniles of pink salmon Oncorhynchus gorbuscha in the Malaya Khuzi River (north-east of Sakhalin Island) in 2023

Abstract

Downstream juveniles of pink salmon Oncorhynсhus gorbuscha were counted in the Malaya Khuzi River (Smirnykh district, Sakhalin Region) from May 17 to July 8, 2023. In this period, the water temperature had in- creased from 3.8 to 13.7 оC, floods were absent, except insignificant water rising after rains on May 27–29, June 12–14, and June 18–20. The majority of juvenile pink salmon (98.9 %) migrated within 23 days from May 23 to June 14, with the peak of migration on June 8 when the water temperature was 8.1 оC. The number of pink salmon juveniles migrated from the Malaya Khuzi River in 2023 was estimated as 8.77.106 ind.