Abstract:
Environmental DNA (eDNA) technology is an essential tool for monitoring living organisms in ecological research. The combination of eDNA methods with traditional
methods of ecological observation can significantly improve the study of the ecology of rare species. Here, we present the development and application of an eDNA
approach to identify rare sturgeons in the lower reaches of the Ural River (Zhaiyk)
(~1084 km). The presence of representatives of the genus Sturgeon was detected at
all sites in spring (nine sites) and autumn (ten sites) while they were absent during
the summer period, consistent with their semi-anadromous ecology. Detection in
spring and autumn indicates the passage of spring and winter forms to the lower and
upper spawning grounds, respectively. This study confirms the difficulties of speciesspecific identification of Eurasian sturgeon and provides the first documented eDNA
detection of specimens of the genus Sturgeon in the Ural River. It also provides a
biogeographic snapshot of their distribution, experimentally confirming their seasonal
migrations in the lower reaches of the river. The successful detection of sturgeon
motivates further eDNA surveys of this and other fish species for accurate species
identification and population assessment, opening up prospects for the management
of these threatened species.
