Growth and exploitation rate of Common cuttlefish, Sepia officinalis in Ghanaian Coastal Waters

This study presents a preliminary assessment of growth and mortality parameters for Sepia officinalis along the coasts of Tema, Sakumono, and Ningo-Prampram, Ghana. A total of 264 specimens were randomly purchased from fishermen between  January and December 2020. Samples obtained were measured for mantle length and analyzed for growth and exploitation  rates using TropFishR software. Mantle length ranged from 3 cm to 26.7 cm, with a mean of 12.4 ± 0.4 cm. Mantle length frequency data fitted to the von Bertalanffy Growth Function yielded an asymptotic length (Linf) of 30.23 cm, a growth coefficient (K) of 0.57 year^-1, and a longevity of 5.0 years. Mortality estimates showed a total mortality rate (Z) of 1.14 year^-1, a natural mortality rate (M) of 0.89 year^-1, and a fishing mortality rate (F) of 0.25 year^-1, with an exploitation rate (E) of 0.22. The lower fishing mortality rate reflects low commercial demand for S. officinalis among artisanal fisherfolk in Ghana. The exploitation rate shows that the species along Ghana’s coast is underexploited, though at a sustainable level. Nevertheless, as a precautionary management measure, fishing effort should be monitored to ensure that biological reference points for sustaining this species are not exceeded.