Estimation of Optimum Mesh Size and Age at First Capture of Caspian Kutum (Rutilus kutum Kamensky, 1901) Using Yield per Recruit Model in Beach Seine Fisheries of Mazandaran Province, Southern Caspian Sea

rezaei, arsalan; raeisi, hadi; Haghparast, Sarah; Patimar, Rahman; Jafaryan, Hojjatollah

Volume 17, Issue 3 (Autumn 2025) 3 2025, 17(3): 68-80 | Back to browse issues page

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rezaei A, raeisi H, Haghparast S, Patimar R, Jafaryan H. Estimation of Optimum Mesh Size and Age at First Capture of Caspian Kutum (Rutilus kutum Kamensky, 1901) Using Yield per Recruit Model in Beach Seine Fisheries of Mazandaran Province, Southern Caspian Sea. 3 2025; 17 (3) :68-80
URL: http://jmb.ahvaz.iau.ir/article-1-1026-en.html

Estimation of Optimum Mesh Size and Age at First Capture of Caspian Kutum (Rutilus kutum Kamensky, 1901) Using Yield per Recruit Model in Beach Seine Fisheries of Mazandaran Province, Southern Caspian Sea

Arsalan Rezaei

, Hadi Raeisi

, Sarah Haghparast

, Rahman Patimar

, Hojjatollah Jafaryan

Department of Fisheries, Faculty of Agriculture and Natural Resources, Gonbad Kavous University, Gonbad Kavous, Iran.

Abstract: (379 Views)

study aimed to estimate the growth parameters and optimal fishing strategies for the Caspian kutum (Rutilus kutum) using the Yield per Recruit (YPR) model in beach seine fisheries along the southern Caspian Sea (Mazandaran Province) from October 2023 to March 2024. A total of 286 fish were sampled, of which 149 (65 males, 84 females) were selected for biological and age-gender analysis. The estimated asymptotic weight (W∞) for the population, males, and females was 3619 g, 2011 g, and 3807 g, respectively. Estimated natural mortality (M) was 0.16 yr⁻¹ for the whole population and 0.15 and 0.35 yr⁻¹ for females and males, respectively. Corresponding fishing mortality (F) values were 0.33 yr⁻¹ (population), 0.26 yr⁻¹ (females), and 0.55 yr⁻¹ (males). Based on the YPR model, the optimum fishing mortality (F_MAX) was 0.30 yr⁻¹, and the optimum age at first capture (T_C) was 4 years, equivalent to 38 cm in fork length. The F_0.1 values were 0.21, 0.27, and 0.25 yr⁻¹ for the whole population, females, and males, respectively. Maximum sustainable yield estimates were fitted using maximum likelihood between model and observed biomass data, indicating a total biomass of 6,243 tons in 2023. The results highlight fluctuations in cohort biomass and emphasize the need for optimizing mesh size and fishing effort to support sustainable exploitation of R. kutum stocks in the region.

Keywords: Rutilus kutum, Yield per Recruit, FMAX, Caspian Sea, Mesh Size, Stock Assessment.

Full-Text [PDF 1122 kb] (188 Downloads)

Type of Study: Applicable | Subject: Fisheries
Received: 2025/08/7 | Accepted: 2025/11/12 | Published: 2025/11/12