Тип публикации: статья из журнала
Год издания: 2021
Идентификатор DOI: 10.1007/s10641-021-01155-y
Ключевые слова: No-growth time, number of circuli, seasonal migration, Thymallus arcticus, Thymallus baicalensis
Аннотация: The seasonal formation of annual rings on the scales of Baikal grayling from the middle reaches of the Yenisei River has been studied to find out the reasons for the high growth rate of the grayling under altered temperature regime downstream of the dam of the Krasnoyarsk Hydroelectric Plant. The number of circuli outside the last Показать полностьюidentified annuli and in the second, third, and fourth completed annuli was estimated on 569 fish caught during the annual cycle. The von Bertalanffy growth function was used to describe the increment in the number of circuli over a year. The calculation showed that a new annual ring was produced in July. In November, there was no statistically significant difference between the circulus number in scale increment and the circulus number in the corresponding completed annuli of older fish. Thus, despite the increased duration of the period with optimal water temperatures downstream of the dam of the Krasnoyarsk Hydroelectric Plant, fish growth was observed in a limited period of the year, from July to November. The probable reason for the high growth rate of grayling in the study area is that the fish do not have to waste energy on seasonal migration to the tributaries. Taking into account that grayling biomass production in the middle Yenisei occurs from July to November, we can recommend shifting the dates of commercial fishing for grayling to the end of this period—November–December.
Журнал: Environmental Biology of Fishes
Выпуск журнала: Т. 104
Номера страниц: 1293-1302
ISSN журнала: 03781909
Издатель: Springer Science+Business Media B.V., Formerly Kluwer Academic Publishers B.V.