Background and Objectives: Stock Assessment of marine aquatic is essential for modern management and sustainable conservation of fishery species, which has been rapidly developed by improving the ability of computer simulation with stock assessment methods, and for sustainable management and exploitation of fish stocks, knowledge of parameters such as age, growth and reproductive biology fishes are essential, and the output information can be used to plan and develop fisheries programs in the future. Fishing management has a wide range of goals, which include identification of aquatic population, assessment of stocks, use and development of fishing tools in order to efficiently exploit the stock and ensure the benefits of fishing users by providing a sustainable harvest deal. Stock assessment models are one of the strategies used to preserve fishery species.
Methods: In this study, some biological characteristics of greenback mullet fish were investigated during six months of 2023 in the coastal waters of Bandar Abbas. For this purpose, after sampling, 120 of the fishes caught were transferred to the laboratory for biometry of length and weight parameters and were subjected to biometrics. After morphometric analysis of greenback mullet samples, fish growth parameters such as Growth performance index, condition index, von Bertalaneffy growth function (VBGF), mortality coefficients and exploitation ratio were calculated using FiSAT software processing.
Findings: The results of the study showed that the average total length and weight of greenback mullet fish were 11.06 cm and 21.90 gr, respectively. In this fish, the relationship between total length and total weight was obtained as W=0.1886TL1.9226. The parameter of condition index in the entire sampling period had strong fluctuations in the first half of the sampling period and did not change significantly in the second half and was almost the same. Among the parameters calculated, we can mention the growth function of von Bertalaneffy growth function and factors such as forked length, growth coefficient and t0 were calculated as 20 cm, 1.1 and -0.1 per year, respectively. Total and natural mortality rates were estimated as 2.56 and 2.07 per year for the samples, respectively.
Conclusion: Stock assessment is the process of collecting, analyzing and reporting fish population information to determine changes in the abundance of fishery stocks in response to fishing and to predict the future trends of stock abundance as much as possible. In this study, the results showed that greenback mullet fish in the coastal waters of Bandar Abbas are young fish. For both males and females, the growth index is the highest, and overfishing, especially during the spawning seasons, has messed up the regeneration of the young population, Therefore, not having proper management in fishing can damage this valuable stock in the coastal waters of Bandar Abbas. Therefore, it is suggested that this study be re-evaluated in a longer period of time and with a larger number of samples so that the results can be proven with more certainty. |