Population dynamics of Sardinella aurita (Val., 1847) within Ghana’s coastal waters

Authors

  • Samuel KK Amponsah CSIR - Food Research Institute, Box M 20
  • Patrick K Ofori Danson Department of Marine and Fisheries Sciences, University of Ghana, Box LG 25, Legon
  • Francis KE Nunoo Department of Marine and Fisheries Sciences, University of Ghana, Box LG 25, Legon
  • Godfred A Ameyaw Australian National Centre for Ocean Resources and Security, University of Wollongong, NSW 2522

DOI:

https://doi.org/10.3329/ralf.v4i3.35103

Keywords:

Round sardine, Exploitation, Growth, Mortality, Recruitment, Overfishing

Abstract

Following the declining stocks of Sardinella aurita within the coastal waters of Ghana, this study aimed at examining some population parameters of Sardinella aurita as a guide for managing this important stock sustainably. Length-frequency data of 717 samples were obtained from June, 2014 to January 2015 and measured for total length with the resultant data analyzed using FiSAT II. The asymptotic length (L∞) and growth rate (K) were 21.53 cm SL and 0.25yr-1 respectively. The theoretical age at birth (t0), longevity (tmax) and growth performance index (ϕ) were -0.74yr-1, 12 years and 1.849 respectively. Total mortality rate (Z), natural mortality rate (M) and fishing mortality rate (F) were 3.17, 0.76 and 2.41yr-1 respectively. The ages at first recruitment and first capture signaled future collapse of the stock, in the absence of proper management interventions. VPA outcome showed that mid- lengths of 11 cm and 12 cm SL experienced the highest harvesting rate with MSY estimated at 7733 tons. The recruitment pattern was continuous with two major recruitment pulses. Exploitation rate (Ecurr=0.76) was higher than the maximum exploitation rate (Emax=0.56), indicating unsustainable exploitation. Further, the fishing regime fell within the overfished stage based on the Quadrant Rule. For sustainable exploitation of this commercial fish species, implementation of relevant biological reference points through reduction in fishing efforts, creation of marine protected areas and mesh size regulation are urgently advocated.

Res. Agric. Livest. Fish.4(3): 237-248, December 2017

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Published

2017-12-29

How to Cite

Amponsah, S. K., Danson, P. K. O., Nunoo, F. K., & Ameyaw, G. A. (2017). Population dynamics of Sardinella aurita (Val., 1847) within Ghana’s coastal waters. Research in Agriculture Livestock and Fisheries, 4(3), 237–248. https://doi.org/10.3329/ralf.v4i3.35103

Issue

Section

Fisheries