Increasing the Productivity of Ghanian Aquaculture

Project summary

Aquaculture continues to be an important sector in the Ghanaian economic development agenda. Increased aquaculture production is the government’s strategy to bridge the 500,000 tonne fish deficit currently met through imports (over US$ 200 million annually). Recent production estimates show that only half of the 2018 production target was achieved (MFAD, 2017) and growth in the industry has largely come from the culture of tilapia on the Volta Lake. Aquaculture productivity in semi-intensive ponds remains low at 2.0t/ha annually compared to 5.0t/ha in similar systems in Asia. In spite of the growth seen over the last decade, development of the sector is hampered by three main factors: 1. High feed costs due to reliance on imported fishmeal and fish oil in aquaculture feed; 2. Poor water quality and low quality of fingerlings; 3. Lack of aquaculture species diversification (tilapia production accounts for >80%).

Outputs

Midterm report:
A new trial is underway with 3 carbohydrate sources (rice, maize, and wheat brans) at 20% inclusion level to ascertain their effect on floatability. The source with the best floatability will be tried at different inclusions for optimum performance in tilapia.
Two experiments on water quality dynamics in ponds with and without fish (control) in the rainy season and dry seasons were completed (July 2019 to June 2020). At the end of the study, 7 parameters; DO, pH, temperature, conductivity, total dissolved solids, NH4, and turbidity were noted to be critical to tilapia culture in ponds.
Initial results showed that the mass mortalities of Heterotis larvae after 8 days post-hatch were due to starvation as larvae deplete their yolk-sac within 8 days. Trials with artemia and rotifers showed that larval growth and survival were better with artemia. Weaning onto particulate diets at 5 weeks was unsuccessful as all treatments had mass mortalities within 4 days except the artemia control.