Population Dynamics of Gudusia chapra (Hamilton, 1822) from Lake Kaptai, Bangladesh

Aims: This study aimed to assess the population dynamics of Gudusia chapra in Lake Kaptai, Bangladesh, utilizing FiSAT II software for comprehensive analysis. The key objective was to determine growth parameters, mortality rates, exploitation status, and length-weight relationships to inform policy.

Study Design: The study employed a quantitative approach, utilizing length frequency data collected from Lake Kaptai. FiSAT II software facilitated the estimation of population dynamics parameters, employing the Von Bertalanffy growth equation and other relevant analyses.

Place and Duration of Study: The research was conducted in Lake Kaptai, Bangladesh, focusing on the intricate aquatic ecosystem from November 2003 to October 2004. Data collection and analysis spanned an extensive duration, providing a robust understanding of the population dynamics of G. chapra.

Methodology: FiSAT II software was utilized for population dynamics estimation, with a particular focus on growth parameters, mortality rates, and exploitation status using Von Bertalanffy growth equation. Length-weight relationships were also determined. Recruitment patterns were observed, and key indices, including the growth performance index calculated.

Results: The estimated asymptotic length (L∞) and growth coefficient (K) of G. chapra were found to be 19.95 cm and 0.89 year-1 respectively. Natural mortality (M), fishing mortality (F) and total mortality (Z) rates were 1.85, 2.21 and 4.06 year-1 respectively. The exploitation rate (E) indicated overfishing, with a value of 0.54, which exceeded the optimum E (E=0.5). The growth performance index (φ´) of 2.54 was recorded, and the recruitment pattern occurred between April and July.

Conclusion: The study concludes that G. chapra in Lake Kaptai is experiencing overfishing, as indicated by the elevated exploitation rate. Understanding the growth parameters and mortality rates is vital for sustainable fisheries management in the region.

Implication: The findings have significant implications for fisheries management, highlighting the urgent need for measures to mitigate overfishing of G. chapra in Lake Kaptai. Implementing conservation strategies and monitoring recruitment patterns are crucial for ensuring the long-term sustainability of this important fish species.