Publication Date:
2021-05-19
Description:
Practical phase of the project aimed at studying and determination of the most appropriate time for sturgeon
catch was conducted at 10 catch stations (2 in each region) in Guilan, Mazandaran and Golestan provinces in
2002 and 2003. Number of catch stations was 4 in Guilan and Mazandaran provinces each and 2 in Golestan
province. The project was carried out following the ratifications of the high committee for sustainable utilization
of sturgeons which passed through in 2001. Considering the results on factors like average caviar yield, quantity
and quality of produced caviar, sex composition of caught spawners and catch per unit effort we found that the
average caviar yield of Persian sturgeon in all three Guilan, Mazandaran and Golestan provinces was higher in
spring catch than autumn and winter and in winter catch was higher than autumn while the amount of caviar
obtained was higher in autumn. Considering sex composition percentage of mature female caught was higher in
spring than other seasons. Catch stations located in Guilan and western and central Mazandaran showed almost
similar condition. Spring catch from late march (last 10 days) up to the 10th of May, autumn catch from late
September and early October (23 September- 2 October) to the 1
st December, and winter catch from 1
st to 21st march are suitable period for catch. At the Khazarabad catch station the suitable time of catch differs from other
stations therefore the proper time for catch appears to be 10- 20 may in spring and 21- 30 January in winter catch
seasons. The quality and quantity of catch is suitable in spring from 21- 31 march to 21- 31 may, in autumn catch
from 12- 22 October to 11- 21 December and in winter catch from 9- 19 February to 11- 20 march at catch
stations located in Golestan province. As for stellate sturgeon at catch stations of Guilan and Mazandaran
provinces the spring catch from 21 march specially from 21 April to 20 June was suitable and all other
quantitative and qualitative factors confirmed better quality and quantity of catch in this period (21 April- 20
June) in comparison to other seasons. Gill nets (lower in number as compared to other sturgeons) could be set up
beginning from 20 February to 20 March in winter catch. Our study showed quantitative and qualitative increase
in catch from 9- 19 April to the end of decade from 22-31 May suggesting a suitable time of catch for stellate
sturgeon in Golestan province. Based on our quantitative and qualitative results the summer catch is not suitable
for Persian sturgeon and stellate sturgeon and winter catch for stellate sturgeon.
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Sturgeon fishes
;
Persian sturgeon
;
Stellate sturgeon
;
Time of catch
;
Sex composition
;
Determination
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
112pp.
