Hydroacoustic complexes on the rivers of Kamchatka
09 August 2022

Hydroacoustic complexes on the rivers of Kamchatka

Scientists of the Kamchatka branch of VNIRO continue long-term monitoring hydroacoustic studies on the salmon rivers of Kamchatka.

Kamchatka is one of the few fisheries regions where an innovative research method is used to monitor the number of fish – with the use of hydroacoustic complexes. The main objectives of these studies are to assess the number of spawning stocks and operational regulation of sockeye salmon fishing in the Ozernaya and Kamchatka rivers.
 
Pacific salmon producers, when entering rivers, make massive anadromous migrations to spawning grounds located in the upper reaches of river basins. At the same time, their stocks are exposed to fishing effects at all stages of the spawning course in marine and river fishing areas. In this regard, it is extremely important to determine the exact number of fish that have reached the spawning site directly, since the number of spawned producers is the basic criterion for obtaining estimates of the values
future spawning returns of Pacific salmon. The information obtained at these water bodies is an essential part of monitoring sockeye salmon stocks.
 
Also in recent years, another direction of using hydroacoustic equipment has been developed - accounting for the number of Pacific salmon in the coastal waters of Kamchatka. Of the most significant works, it is possible to note the hydroacoustic accounting of the number of salmon producers during pre-spawning migrations in the Kamchatka Gulf, as well as during the migration of juveniles to the open waters of the Bering Sea from the northeastern coast of the peninsula (the bays of Karaginsky and Corfu). The results of the research are used: firstly, in the operational regulation of the Pacific salmon fishery R. Kamchatka, secondly, to obtain information on the survival of juvenile salmon in the coastal waters of the Karaginsky subzone in order to further predict their returns.
 
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The first attempts to account for the assessment of spawning numbers and regulation of salmon fishing using modern hydroacoustic systems were made in the first half of the 2010s in the basins of the Ozernaya and Kamchatka rivers. The research was focused on the exploitation of the stocks of the two largest herds of sockeye salmon, which currently provide about 80-90% (25-35 thousand tons) of the catch of the species in the Russian Far East. Starting from the second half of the 2010s, these accounting works in these water bodies are carried out at the monitoring level. For example, hydroacoustic studies have been conducted in the Kamchatka Gulf since 2018, and in the bays of the northeast of Kamchatka for the second year.
 
VNIRO Press Service