Integrated Monitoring of Escapement of Pacific Salmon Spawners to the Kamchatka River in Real-Time Mode

Аннотация

A method for rapid quantification of escapement of Pacific salmon spawners into the Kamchatka River catchment basin and the mathematical models for assessment of Pacific salmon spawners, escapement through a river cross section have been developed based on data from the integrated monitoring of their escapement dynamics including aerial observations, hydroacoustic surveys, and test drift-net sampling, as well as using data on the biological characteristics of spawners. These data allowed retrospective qualitative and quantitative assessment of levels of escapement of sockeye, chum, and coho salmon spawners to their spawning grounds; the current fishing efficiency in the river was evaluated. The escapement of sockeye salmon has been evaluated as being at the level of its medium reproduction success. To achieve the conditions that would provide the highest level of reproduction of Kamchatka sockeye salmon populations, the regulation of fishing should focus on a reference level of approximately 850 000 spawners. This level is achievable in case of the systematic overcrowding of the existing reproduction centers and the involvement of the populations that previously lost their importance in the process. The level of escapement of chum and coho salmon spawners in the study period can be evaluated as medium and high. A method of test Chinook salmon catches to obtain a general estimate of escapement of this species prior to the beginning of the fishing season has been developed and implemented.