Сurrent state of artificial reproduction of chum salmon in Primorye Region

Results of 4 salmon hatcheries operation in Primorye Region are overviewed. Dynamics of chum salmon producers return to the rivers is presented for 4 last years. Recent tendency of shifting the peak of return from middle October to late September — early October is noted both for the rivers flowing into Peter the Great Bay (Barabashevka) and for the rivers of central Primorye (Verbnaya and Milogradovka). High percentage of producers aged 2+ was observed in the hatchery rivers in some years (32.9 % in the Barabashevka in 2019, 31.0 % in the Verbnaya in 2020, 37.8 % in the Bezymyanny in 2020). Interannual fluctuations in the number of producers return are possibly caused by malfunctions of hatcheries. A problem of water supply to the hatcheries is considered. Expediency of temperature control at hatcheries is shown. Data on release of chum salmon juveniles in the last decade are presented for each hatchery: the number of juveniles released, the average weight of juveniles, and the timing of release. Total release to the Barabashevka River was 119.29 . 10 6 juveniles, to the Ryazanovka — 114.24 . 10 6 juveniles, to the Poyma — 49.43 . 10 6 juveniles, to the Narva — 6.02 . 10 6 juveniles, to the Brusya — 3.11 . 10 6 juveniles, to the Verbnaya — 69.66 . 10 6 juveniles, to the Milogradovka — 1.00 . 10 6 juveniles, to the Lidovka — 1.71 . 10 6 juveniles, to the Bezymyanny — 69.45 . 10 6  juveniles, and 2.00 . 10 6 juveniles each to the Kievka and Margaritovka Rivers.