Population Dynamics of Four Fin Fish Species from a Tropical Estuary

• Snigdhodeb Dutta ^[1]
  1. [1] Cochin University of Science and Technology

     Cochin University of Science and Technology

     India

     
• Localización: Thalassas: An international journal of marine sciences, ISSN 0212-5919, Vol. 39, Nº. 1, 2023, págs. 333-341
• Idioma: inglés
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• Resumen

  • Data on four fin fish species were collected from the Cochin estuary from January 2018 to December 2019. The present study investigated the growth, mortality and stock characteristics of four fin fish species from the Cochin estuary, on the basis of the length-frequency data. E. thoracata had an asymptotic length (L) of 178.5 mm and a growth constant (K) of 0.55 year−1 , while N. blochii had an asymptotic length (L) of 126 mm and a growth constant (K) of 0.73 year−1 . For all species studied, the age at zero length (t0) was computed and varied from −0.13 to -0.25. P. parsia had longevity (tmax) of 7.14 years and a growth performance index (Ø) of 3.964, while S. argus had 4.05 and 4.32, respectively. The projected total mortality (Z), natural mortality (M), and fishing mortality (F) of N. blochii were 2.65, 0.98, and 1.67 year-1, respectively; on the other hand, the estimated total mortality (Z), natural mortality (M), and fishing mortality (F) of E. thoracata indicating overexploitation were 1.36, 0.74, and 0.62. The significant finding is that the exploitation level is observed for each species surpassed the optimum exploitation rate considered for sustainable fisheries indicating overfishing of those investigated species. Management measures such as mesh size limitations, restricted fishing efforts, and the proclamation of restricted seasons are required to save these species from extinction