Publication Date:
2021-05-19
Description:
The present study was carried out on the basis of data collected from the catch of beach seine operating in the
southern coast of the Caspian Sea for two species carp (Cyprinus carpio) and roach (Rutilus caspicus) in 2015 –
2016. Besides, the changes in patterns of recruitments were evaluated on the basis of the historical catch
statistics and the released number of the two species which taken from the G.D office of Golestan province. The
age structure and length-frequency distribution of the two species were determined. The largest catches of carp
and roach belongs to the age groups (5, 6 and 1, 2) year olds, respectively. In order to estimate the growth pattern
of the two species, the length-weight relationships were determined. The von Bertalanffy growth
parameters (L∞, K and t0) and mortality were calculated by the ELFFAN I method using FiSAT program for two
species. The von Bertalanffy growth equation obtained was Lt=75. 72 (1-e
(-0. 12 (t+0. 5)) in 2015 and Lt=72. 75 (1-e
(-0. 13 (t+0. 26)) in 2016 for carp and Lt=30. 82 (1-e (-0. 27 (t+1)) in 2015 Lt=24. 92 (1-e (-0. 5 (t+0. 35)) in 2016 for Roach.
The estimates of von Bertalanffy growth parameters were compared with the carp populations in other areas.
The total coefficient of mortality (Z) using the linear curve method of fishing was estiamted 1. 3 years for carp
and 0.86 for roach in both years. The natural mortality (M) using the Pauli experimental formula was calculated
0.23 years in 2015 and 0.24 years in 2016 for carp and 0.5 years in 2015 and 0.46 years in 2016 for roach. The
biomass of two species carp and roach was estimated 96.7 and 68.4 tone in 2015 and 4.8 and 21.8 tone in 2016,
respectively.
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Cyprinus carpio
;
Rutllus caspicus
;
Stock assessment
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
33pp.
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