The Role of Environmental Conditions in Various Types of Estuaries for the Productivity of Pacific Salmon Populations of Kamchatka

Koval, Maksim; Горин, С. Л.

doi:10.23849/npafctr15/90.93.

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Этот вывод основан на том, что приливы -это постоянно действующий фактор, к изменчивости которого нерка р. Камчатки давно приспособилась. При этом и наш многолетний опыт работы в устьях рек полуострова (Koval, Gorin, 2019), и опыт местных рыбаков свидетельствуют, что определенная связь между приливами и динамикой заходов лососей в устья рек (в том числе р. Камчатки) существует. Но она проявляется только в суточной неравномерности захода производителей, которым легче преодолевать устьевой участок реки в приливную фазу, когда течение замедляется (или поворачивает в обратную сторону), а глубины в устье реки увеличиваются.…”

Section: распределение и миграции лососей в прибрежных водахunclassified

Factors determining spawning run dynamics and current state of sockeye salmon <i>Oncorhynchus nerka</i> resources in the Kamchatka River

Koval

Тепнин

Горин

et al. 2021

Issledovaniâ vodnyh biologičeskih resursov Kamčatki i Severo-Za

View full text Add to dashboard Cite

Hydrological regime and morphodynamics of the outlet part of the Kamchatka River, dynamics of mixing zone, patterns of juvenile Pacific salmon distribution and migration in the coastal waters of Kamchatsky Gulf in the zone of operating trap nets were analyzed on the results of complex field works prowided in summer period in 2018–2019; fishing and specifics of sockeye salmon spawning run in the river was described. In the course of analyzing the entire complex of available long-term data, an assessment of the likely impact of some key factors on the dynamics of anadromous migration of sockeye salmon in the Kamchatka River was made; biological statistics of spawners and current state of reproduction of this stock was demonstrated. It is found, that natural environmental factors, neither abiotic nor biotic (including fish health as population internal factor), could not cause disturbance of sockeye salmon spawning run dynamics in the Kamchatka River in recent years. Smoller body size and physiological imperfection of the spawners before the anadromous migration due to effects of high number of pink salmon in recent years are suggested to be the most likely cause of spawning run delay in late sockeye salmon morph. Regime of commercial use of the stock and general increasing pressure on the spawning stock by coastal fisheries are demonstrated to be the strongest outer factors to affect modern state of the resources and sockeye salmon population structure in the Kamchatka River, causing permanent escapement deficiency on spawning grounds in the river basin (first of all in the late morph), and also infact lead to disballance between different subpopulation groups in the composition of the stock. Recommendations in order to provide recovery and sustainable level of the Kamchatka River sockeye salmon stock are given in the perspective of more efficient commercial use of the stock next several years; highlights for further researches are outlined.

show abstract

Section: распределение и миграции лососей в прибрежных водахunclassified