įrancis R (1990) Backcalculation of fish length: a critical review. įisher JP, Pearcy WG (2005) Seasonal changes in growth of coho salmon ( Oncorhynchus kisutch) off Oregon and Washington and concurrent changes in the spacing of scale circuli. ĭynesius M, Nilsson C (1994) Fragmentation and flow regulation of river systems in the northern third of the world. ĭickson NE, Carrivick JL, Brown LE (2012) Flow regulation alters alpine river thermal regimes. Ĭunjak RA, Power G (1987) The feeding and energetics of stream-resident trout in winter. Ĭrisp DT (1996) Environmental requirements of common riverine European salmonid fish species in fresh water with particular reference to physical and chemical aspects. īilton HT, Robins GL (1971) Effects of starvation, feeding, and light period on circulus formation on scales of young sockeye salmon ( Oncorhynchus nerka).

īentley KT, Schindler DE (2013) Body condition correlates with instantaneous growth in stream-dwelling rainbow trout and Arctic grayling. īacon PJ, Gurney WSC, Jones W, McLaren IS, Youngson AF (2005) Seasonal growth patterns of wild juvenile fish: partitioning variation among explanatory variables, based on individual growth trajectories of Atlantic salmon ( Salmo salar) parr. Īndrianova AV (2013) Dynamics of development of Yenisei zoobenthos in the lower tail of the Krasnoyarsk HPP. 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.Īmundsen PA, Knudsen R (2009) Winter ecology of Arctic charr ( Salvelinus alpinus) and brown trout ( Salmo trutta) in a subarctic lake. 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. 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. 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. The calculation showed that a new annual ring was produced in July.

The von Bertalanffy growth function was used to describe the increment in the number of circuli over a year. The number of circuli outside the last identified annuli and in the second, third, and fourth completed annuli was estimated on 569 fish caught during the annual cycle. 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.

Circuli spacing and annulus formation