4 / 2025-05-07 17:48:28

Restoration of Wild Sturgeon Populations of the Lena and Amur rivers

Siberian sturgeon Acipenser baerii Brandt, 1869, Amur sturgeon Acipenser schrenckii Brandt, 1869, Kaluga Huso dauricus Georgi, 1775, the Lena River, the Amur River, fisheries, current state, restoration

Over a quarter of a billion years of their existence, the Acipenseriformes have survived many climatic cataclysms and have come to this day, practically unchanged. But human intervention in their habitat and unbridled fishing pressure has led their populations to the brink of extinction over a century and a half. Artificial reproduction of sturgeon, which has become widespread since the 1950s with the start of large-scale construction of dams, and the ban on commercial fishing partially compensate for the numerical damage inflicted on the populations. But at the same time, the diversity of genes and the ability to self-reproduce are reduced in artificially maintained populations. The sturgeon populations of the once richest basins of the Caspian and Azov Seas are currently maintained mainly by artificially bred individuals, and therefore it is not entirely correct to regard them as wild and predict their independent reproduction. However in Russia there are huge waterways, where sturgeon populations have, to some extent, retained their original state. From the Ural Mountains to the Anadyr Lowland and from 48° to 74° N, the Siberian sturgeon, Acipenser baerii Brandt, 1869, inhabits all large rivers and their tributaries. The relatively small Amur River basin is the habitat of the Amur sturgeon, Acipenser schrenckii Brandt, 1869, and the Kaluga, Huso dauricus Georgi, 1775. The Kaluga can be found in the sea area from the northern shores of the Sea of Okhotsk to Southern Primorye and Hokkaido Island. These species have historically been the objects of commercial fishing, which on the Amur reached its peak in the late 1800s, and on the main Siberian rivers in the early to mid-1900s. Excessive catch volumes on the background sparse distribution of the resource, as well as neglect of the permitted catch size and fishing periods, led to a sharp decline in the sturgeon stock. Strict regulation of fishing partially contributed to their recovery. However, the construction of hydroelectric power stations on the Ob’, Yenisei, Zeya and Bureya rivers led to the final stoppage of fishing and the inclusion of sturgeon populations of these and other Siberian rivers in the Red Book of the Russian Federation. The sturgeon populations of the Lena and Amur rivers are luckier. There are no dams on these rivers, natural spawning grounds and floods have been preserved here. The Lena River is currently the only body of water where commercial sturgeon fishing is permitted. Artificial reproduction of sturgeon in the Amur and Lena rivers began in the 2000s. The volumes of releases of artificially bred juveniles are insignificant and far from the volumes of theoretically possible natural spawning. Therefore, the sturgeon populations of these two rivers are maintained due to natural spawning and retain natural genetic polymorphism, which is of the greatest interest in terms of their ability to self-recovery in modern conditions of existence. Our study provides a retrospective review of fishery dynamics, assessment of the current state and self-restoration of Siberian sturgeon of the Lena River and Amur sturgeon and Kaluga of the Amur River.