Growth, Mortality and Exploitation Rates of <i>Sarotherodon melanotheron</i> in the Dominli Lagoon of Ghana

Abstract

Sarotherodon melanotheron population of Dominli Lagoon in the Western Region of Ghana was studied for its growth and mortality parameters as well as exploitation rate. The study generally aimed at providing basic information necessary for the assessment and management of the fish stock in the lagoon. Using FiSAT programme, estimates of the prominent growth and mortality parameters of S. melanotheron were: L ∞ = 20.48 cm, SL and K = 0.97yr -1 . Total, natural and fishing mortalities of the population were determined as 3.86 y -1 , 2.02 y -1 and 1.84 y -1 , respectively. The growth estimates and the maturity-length ratio (≈ 0.7) suggested that the S. melanotheron population was not stunted. The fast growth rate and continuous recruitment exhibited by S. melanotheron were indicative of its suitability for culture. The present exploitation rate (0.48) indicates that the black-chinned population is not overexploited. The Y′/R and B′/R curves as well as all-year-round recruitment show that the current exploitation rate could be maintained for sustainable and rational exploitation of the black-chinned tilapia stock.

Bio‐ecological studies on two cichlids in the Brimsu reservoir of Ghana

“…Arizi et al. (2014) reported a sex ratio of 1:1.5 which is similar to the finding of the current study. Deviation from the normal 1:1 sex ratio periodically or permanently can occur during spawning, temperature variation, distribution of organisms in time and space and the availability of food (Famoofo & Abdul, 2020).…”

“…This implies that fishes from the Brimsu reservoir will reach their asymptotic length faster than fishes from Nyanza Gulf (Kenya), Siyambalangamuwa, Balaluwewa and Ibbankatuwa reservoirs in Sri Lanka. The L ∞ value for S. melanotheron was high, even though the K and M values were smaller than those reported in the Dominli and Etsir Lagoons (Arizi et al, 2015;Tibu et al, 2019). Maximum length reached by a fish is a crucial factor highly correlated with metabolism and other life-history traits (Binohlan & Froese, 2009).…”

“…Arizi et al. (2014) reported a value of 3.42–4.53 for the Dominli Lagoon, and Mireku et al. (2016) reported of 3.95–4.94 for males and 4.08–4.99 for females from the Brimsu reservoir.…”

“…There was no significant difference between the condition factor for males and females (p > 0.05). Arizi et al (2014) reported a value of 3.42-4.53 for the Dominli Lagoon, and Mireku et al (2016) reported of 3.95-4.94 for males and 4.08-4.99 for females from the Brimsu reservoir.…”

Morphological relationships, growth patterns and some aspects of reproductive biology of Sind Danio Devario devario (Hamilton 1822)

“…Divakar et al (2017) found that the maximum recruitment percentage was observed in August (31.00%) for Katsuwonus pelamis, where the period remained between July and October. The annual recruitment pattern of Sarotherodon melanotheron found in the rainy season (April -July) and dry season (October -January) had maximum and minimum recruitment in June and February (Arizi et al 2015), which is close to the present findings.…”