Stock assessments of the Black Sea anchovy during the period 1979-1993

The stock assessments of the Black Sea anchovy during the period 1979-1993 were made by Age- and Length-structured VPA. According to the obtained results, the initial anchovy exploited biomass varied from 1421.3 (1979) to 243.3 thousand tons (1990). In 1979 the mean exploited biomass was 1036.5 thou...

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Main Authors: K.B. PRODANOV, M.D. STOYANOVA
Format: Article
Language:English
Published: Hellenic Centre for Marine Research 2001-12-01
Series:Mediterranean Marine Science
Online Access:https://ejournals.epublishing.ekt.gr/index.php/hcmr-med-mar-sc/article/view/12235
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spelling doaj-4a79b8b556e849ed94a425c97c14dded2020-11-24T22:26:35ZengHellenic Centre for Marine ResearchMediterranean Marine Science1108-393X1791-67632001-12-012271510.12681/mms.26310687Stock assessments of the Black Sea anchovy during the period 1979-1993K.B. PRODANOV0M.D. STOYANOVA1Institute of Oceanology, P.O.Box 152, 9000 VarnaInstitute of Oceanology, P.O.Box 152, 9000 VarnaThe stock assessments of the Black Sea anchovy during the period 1979-1993 were made by Age- and Length-structured VPA. According to the obtained results, the initial anchovy exploited biomass varied from 1421.3 (1979) to 243.3 thousand tons (1990). In 1979 the mean exploited biomass was 1036.5 thousand tons. Both assessments are very close because the mean biomass at F=0.5 has to be 73.71% from the initial one. The comparatively low level of fishing activity from 1968-1977 (mean value of F was 0.2407) and the increase in Black Sea productivity predetermined the increase in anchovy biomass during the period 1979-1983. This rise in productivity of the Black Sea implies higher values of the anchovy exploited biomass, but this did not occur due to the increased fishing mortality upon the anchovy, which kept its abundance and biomass at considerably lower levels. The mean value of F was 0.7348 during the period 1983-1986 and reached 1.2487 in 1987-1988. The mean anchovy biomass in 1991 and 1992 was 179.1 and 314.0 thousand tons. In the same years the initial anchovy biomass was 430.5 and 592.1 thousand tons. The mean value of the fishing mortality coefficient in 1991 and 1992 was 0.3889 and 0.6353, respectively. Consequently, the decrease of fishing mortality during the specified years was ohttps://ejournals.epublishing.ekt.gr/index.php/hcmr-med-mar-sc/article/view/12235
collection DOAJ
language English
format Article
sources DOAJ
author K.B. PRODANOV
M.D. STOYANOVA
spellingShingle K.B. PRODANOV
M.D. STOYANOVA
Stock assessments of the Black Sea anchovy during the period 1979-1993
Mediterranean Marine Science
author_facet K.B. PRODANOV
M.D. STOYANOVA
author_sort K.B. PRODANOV
title Stock assessments of the Black Sea anchovy during the period 1979-1993
title_short Stock assessments of the Black Sea anchovy during the period 1979-1993
title_full Stock assessments of the Black Sea anchovy during the period 1979-1993
title_fullStr Stock assessments of the Black Sea anchovy during the period 1979-1993
title_full_unstemmed Stock assessments of the Black Sea anchovy during the period 1979-1993
title_sort stock assessments of the black sea anchovy during the period 1979-1993
publisher Hellenic Centre for Marine Research
series Mediterranean Marine Science
issn 1108-393X
1791-6763
publishDate 2001-12-01
description The stock assessments of the Black Sea anchovy during the period 1979-1993 were made by Age- and Length-structured VPA. According to the obtained results, the initial anchovy exploited biomass varied from 1421.3 (1979) to 243.3 thousand tons (1990). In 1979 the mean exploited biomass was 1036.5 thousand tons. Both assessments are very close because the mean biomass at F=0.5 has to be 73.71% from the initial one. The comparatively low level of fishing activity from 1968-1977 (mean value of F was 0.2407) and the increase in Black Sea productivity predetermined the increase in anchovy biomass during the period 1979-1983. This rise in productivity of the Black Sea implies higher values of the anchovy exploited biomass, but this did not occur due to the increased fishing mortality upon the anchovy, which kept its abundance and biomass at considerably lower levels. The mean value of F was 0.7348 during the period 1983-1986 and reached 1.2487 in 1987-1988. The mean anchovy biomass in 1991 and 1992 was 179.1 and 314.0 thousand tons. In the same years the initial anchovy biomass was 430.5 and 592.1 thousand tons. The mean value of the fishing mortality coefficient in 1991 and 1992 was 0.3889 and 0.6353, respectively. Consequently, the decrease of fishing mortality during the specified years was o
url https://ejournals.epublishing.ekt.gr/index.php/hcmr-med-mar-sc/article/view/12235
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