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This study explored the potential of three local microalgal isolates as feed for oyster larvae in laboratory‐rearing experiments, towards the optimisation of seed production of Crassostrea tulipa to support its large‐scale farming along the West African coast. Three species of local microalgae—Rhodomonas sp., Nannochloropsis sp. and Pseudanabaena sp.—were isolated from waters off the coast of Ghana, West Africa, following a serial dilution technique. The growth performance of the isolates was assessed in the laboratory through daily estimation of cell density until the stationary phase was observed. Characterisation of the microalgal isolates was carried out by estimation of their biovolume, carbon content and energy content. Biovolumes of the microalgae were calculated from the estimated equivalent spherical diameters using proposed geometric shapes and formulae. Carbon weight and carbon energy content were subsequently calculated using derived conversions. The three microalgal isolates showed potential for large‐scale cultivation in the laboratory with marked differences in daily increases in cell densities. Nannochloropsis sp. and Rhodomonas sp. recorded the highest and the lowest peak densities of 2.4 × 105 and 1.5 × 105 cell mL−1, respectively, from an initial inoculating cell density of 1.05 × 105 cell mL−1. The estimated mean biovolumes of Rhodomonas sp., Nannochloropsis sp. and Pseudanabaena sp. were 238.9, 8.182 and 42.42 µm3, respectively, and the corresponding derived carbon energy contents were 1.7 × 10−6, 7.13 × 10−8 and 1.05 × 10−7 J, respectively. Results from a laboratory rearing experiment indicated that the individual microalgal isolates supported the growth and survival of oyster larvae at different scales, but a mixed diet of the three promoted superior growth and survival of C. tulipa larvae. The three local microalgal isolates‐ Rhodomonas sp., Nannochloropsis sp., and Pseudanabaena sp.‐ were well adapted to laboratory culture conditions, and the observed differences in growth and survival of the oyster larvae fed on these algal diets could be due to the differences in diet properties and biochemical compositions of the different species. A combination of the three algal diets, however, provided complementaery nutrients for the optimal growth and survival of C. tulipa larvae. The outcome of this study shows that local microalgal isolates have the potential to support hatchery rearing of C. tulipa, which is essential for the development of commercial mangrove oyster aquaculture in West Africa. [ABSTRACT FROM AUTHOR]

Bluespotted seabream Pagrus caeruleostictus, a member of the family Sparidae, is one of the high‐priced seabream species in Ghana. Although the fish has been exploited in the Gulf of Guinea for over hundreds of years, there is scanty information on the state of the fish stock. Hence, we sought to investigate the exploitation status and aspects of the reproductive biology of the species by collecting monthly length and weight data for 18 months (February 2016 to July 2017). These data were fitted to growth and mortality models. The sexual maturity, fecundity and spawning seasons were also determined within the same period. The growth model of the fish revealed that the asymptotic length (L∞) and growth coefficient (K) values determined were 52.7 cm (total length) and 0.52 year−1, respectively. The mortality models also showed that the fishing mortality (F) of the fish was 2.20 year−1, whereas its natural mortality (M) was 0.83 year−1, with F/M > 0.5 indicating that the fish is over‐exploited. The lengths at first sexual maturity (Lm) of the males and females were 36.2 and 28.0 cm, respectively. Pagrus caeruleostictus, which was found to be highly fecund, had two spawning periods in a year, occurring in September and March, both with unimodal ova diameter frequency distributions. Based on these findings, we recommend that catch limits and other appropriate management measures (e.g. temporal and spatial closures) should be prescribed for the seabream fishery in the Gulf of Guinea to ensure the sustainability of the fishery. [ABSTRACT FROM AUTHOR]

Aquaculture developmental plans represent a nation's determination for self‐reliance on domestic fish production through resilient aquaculture. This study reviewed the 2012 Ghana National Aquaculture Development Plan (GNADP) and sought inputs from industry stakeholders to inform GNADP 2023 using the ecosystem approach to aquaculture (EAA). In furtherance of this, we also investigated the justifications for antibiotic treatments including the assessment of the sector that is supposed to regulate aquaculture growth. The findings suggest that GNADP 2023 must be strategized to address industry sustainability bottlenecks identified as input availability and quality, permitting, regulation and enforcement, financing schemes and technical expertise. In terms of technical expertise, the inclusion of women in aquaculture can diversify the skill sets for the improvement of capacity and competence in good aquaculture practices and fish health management. Sector partnerships can aid in leveraging the expertise and resources among sectors to address persistent industry issues. The justifications for antibiotic treatments are disease management, prophylactics, antibiotic availability, application, and effectiveness, capacity and competence, including regulation and enforcement. This also comprised the sense of ownership and responsibility as farmers feel they must safeguard their investment. It is therefore important for farmers to pursue preventative aquaculture biosecurity measures. The government sector was selected predominantly to regulate aquaculture growth. We however recommended a participatory approach as this could facilitate peer regulation to enhance the regulation and enforcement of aquaculture regulations. The findings in this study are worth considering as it pioneers the adoption of the EAA framework for aquaculture developmental planning in Ghana. [ABSTRACT FROM AUTHOR]

This study examined factors affecting fishers' interest in participating in human immunodeficiency virus (HIV) testing at Elmina fishing community in the Central Region of Ghana. The study additionally inquired of respondents if they would be willing to submit to an HIV test and, if so, if they knew where to go for the test. The study also looked at the barriers that prevented fishers from getting tested for HIV. A cross‐sectional convergent parallel mixed‐method design was used to examine 385 fishers who were at least 18 years old and engaged in any form of fishing activity. Only about 9% of respondents reported having ever tested for HIV. Although the overall testing rate was low, the results indicate a higher testing rate in females than among males. Multivariate analysis shows that sex, age and type of fishing occupation are significant predictors of willingness to test for HIV among the study participants. Even though many people in the study location may know where to get tested for HIV, they are unwilling to do so. Many residents of the research area may be aware of where to get tested for HIV, but they are unwilling to go. This suggests a lack of enthusiasm due to misunderstandings and misconceptions about what HIV testing uptake entails. Additionally, stigmatization is a significant barrier to the acceptance of HIV testing in the study area and needs to be reduced by increased education. [ABSTRACT FROM AUTHOR]

Although small‐scale fisheries and aquaculture provide opportunities to increase fish yield to supplement rural food and income, they remain undeveloped in Ghana. To contribute towards the development of the sectors, this study sought to assess the biology and ecology of Oreochromis niloticus and Sarotherodon melanotheron in the Brimsu reservoir to provide the requisite information for their management. From the results, mean temperature, dissolved oxygen, pH and transparency of the reservoir were 30.03 ± 0.27°C, 3.78 ± 0.38 mg/L, 8.30 ± 0.21 and 69.79 ± 1.76 cm, respectively. S. melanotheron had a sex ratio of 1:1.36; with mean condition factors of 2.177 ± 0.089 and 2.06 ± 0.029 (p = 0.08) for males and females, respectively. The sex ratio of O. niloticus was 1.45: 1; with mean condition factors of 2.208 ± 0.012 and 2.257 ± 0.014 (p = 0.07) for males and females, respectively. Both species exhibited positive allometric growth with no significant differences between the condition factors for males and females. In addition, there was no significant difference between the sex ratios for S. melanotheron but the number of males of O. niloticus was significantly higher than the females (p ˂ 0.05). Size at sexual maturity (Lm), form factor (a3.0), growth coefficient (K), asymptotic length (L∞) and natural mortality (M) of S. melanotheron were 18.00 cm, 0.020, 0.42 year−1, 30.32 cm and 0.64 year−1, respectively. For O. niloticus Lm, a3.0, K, L∞ and M were 18.57 cm, 0.0223, 0.26 year−1, 38.42 cm and 0.41 year−1, respectively. However, the catch per unit effort for O. niloticus was higher than that of S. melanotheron throughout the study period. The conditions of the reservoir were favourable for the growth of these cichlids. It is recommended that measures should be put in place for the sustainable management and exploitation of fish stocks. [ABSTRACT FROM AUTHOR]