The study describes growth pattern, growth parameter, mortality, recruitment pattern, exploitation rate (E) and maximum sustainable yield (MSY) to Panna heterolepis from the Bay of Bengal (Bangladesh). About 1223 specimens were collected from commercial fishermen for 12 consecutive months from January to December, 2019. Length-frequency data were analyzed with FAO-ICLARM Stock Assessment Tool. Moreover, our study recorded different water quality and environmental parameters including pH, rainfall, temperature and DO (dissolved oxygen) from the Bay of Bengal. The findings of the study revealed that the allometric co-efficient (b) value indicated negative allometric growth (<3.00) for P. heterolepis population. Whereas, the population dynamic parameters showed growth coefficient (K) 0.13 year-1, life-span (t max ) 3.85 year and growth performance index (Ø') 2.30. Along with this, P. heterolepis was found to grow rapidly with an asymptotic length (L ∞) of 39.08 cm. We found that the natural mortality (M =0.44 year-1) rate was almost similar with fishing mortality (F = 0.42 year-1). Consequently, the standing stock was not quite sustainable with the existing fishing strategy. Furthermore, the maximum allowable exploitation rate (E max = 0.471) was lower than the recorded exploitation rate (E = 0.490). Subsequently, overfishing is the most focal threat to the wild stock. The recruitment pattern was almost continuous throughout sampling period. Finally, the MSY was assessed at 10234.47 metric tons. Additionally, the environmental parameters denoted that the ecosystem was in a balanced condition for the wild population. The findings would be very useful to introduce appropriate fishing regulations in the Bay of Bengal and nearby ecosystem.
Keywords: Bangladesh; Bay of bengal; Panna heterolepis; Stock assessment.
© 2021 The Author(s).