Оценка состояния эксплуатации запасов речной камбалы в восточной и северо-восточной Балтике и необходимые меры по регулированию ее промысла

The flounder catch has not increased substantially during the last 15 years. Nevertheless, the catch is at a relatively high level, to judge from the biological characteristics of the catches. In order to estimate the level of exploitation of the populations, mortality and growth parameters for the flounder in the eastern part of the Baltic and in the Finland Bay have been determined for the period from 1969 to 1974 by tagging data and biological characteristics using formula from Beverton and Holt, Ricker, Bertalanffy and the Walford-table. The different methods of calculation yielded congruent results. The mortality of mature fish from the East Gotland population was characterized as follows: Z = 0,75, F = 0,45, M = 0,30, the mortality of mature fish from the Finland Bay population was characterized as Z = 0,75, E = 0,40, M = 0,35. The following values have been established for the growth of the East Gotland population: L = 36,5 . . . 38,7 cm, K = 0,19 ... 0,20, W = 629 g, K = 0,17, for the Finland Bay population: L = 29 cm, K = 0,34. The curves according to Beverton and Holt drawn up on the basis of these parameters show that the fishing intensity on flounder stocks in the eastern part of the Baltic (subarea 28) is at the optimal level and that F has to be stabilized in this area by limiting the catch volume. In the north-eastern part of the Baltic (subarea 32) fishing mortality is at a near-optimum level and a certain increase in the catch is possible. The parameters and biological characteristics of the flounder population show good reasons for the following measures for regulating catches in the subareas 28, 29 and 32 (for each area separately): Prohibition of fishing from 1 February to 31 May, dito, from 1 February to 30 June; minimum length (total length) — 21 cm, 18 cm, 18 cm; minimum mesh size — 80 mm, 70 mm, 70 mm. By-catch of young fish has to be returned.

Bibliographic Details

Main Authors:	Vitinsh, M.Ya., Hoziosky, S.A., Lishev, M.N.
Format:	Journal Contribution biblioteca
Language:	Russian
Published:	1975
Subjects:	Flounder, Exploitation of flounder stock, Mortality, Growth rate, ASFA_2015::F::Fish stocks, ASFA_2015::P::Population parameters, ASFA_2015::F::Fishery regulations,
Online Access:	http://hdl.handle.net/1834/15880
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