Design of pumping station for a tidal fish farm in Niger Delta, Nigeria

The design of pumping station for submersible FLYGT pump 3102 version LL to redress the water supply problem of some ponds in the tidal fish farm of African Regional Aquaculture Centre (ARAC) located in Omuihuechi, Aluu, Rivers State, Nigeria was carried out. Prior to the design baseline study was carried out for the proper sitting of the pumping station. The topographic survey of the area indicated gentle sloping woodland, with the highest and lowest elevations of 11.00 m and 1.00 m respectively. The mean peak heights of water in the supply canal during spring and neap tides ranged from 0.95 to 1.45 m and 0.38 to 0.86 m respectively. The flood tide and ebb tide velocities of supply canal water flow varied from 0.40 to 0.75 m/s and 0.75 to 0.92 m/s respectively. Soil particle size analysis indicated loamy clay and clay soils. The results of pumping station design were 1.80 m (length), 1.30 m (width); 3.60 m (height),0.15 m (thickness), I (cement) : 2 (sand) : 4 (gravel) (concrete mixture ratio) and 12 mm (reinforcement bar). Results of pump characteristic calculation were 0.069 m3/s (discharge) ,4.02 m/s (pumping velocity), 5.73 m (total dynamic head), 0.82 m (minimum submergence depth), 5.04 KW (pump power)and 0.40 and 0.30 m ( clearances from floor and wall respectively). The results obtained were considered adequate for the purpose of construction of the pumping station for the pump and the procedures adopted will assist in similar design tasks in the development of fish farms in the Niger Delta Region of Nigeria and beyond

Survey of physical characteristics of the upper reaches of new Calabar River, Niger Delta, Nigeria

One of the priority research projects of the Nigerian Institute for Oceanography and Marine Research (NIOMR) is broodstock development and mass propagation of silver catfish, Chrysichthys nigrodigitatus of which the broodstock is naturally abundant in New Gala River. Selected physical characteristics and water physico-chemical parameters of the upper reach of the New Calabar River at Aluu were investigated. The highest depth value of 9.20 m was recorded in the middle of the river. The width of the river measured during spring high tide and low tide were 174 m and 110 m respectively. The cross-sectional area and average flow velocity of the river were 797.13 m2 and 0.374 m/s respectively. The discharge of the river was computed as 298.13m3/s. The river water was acidic most of the period (Hydrogen ion concentration, pH: 5.12 to 7.43), with low total alkalinity values (4.00 to 12.00 mgCaCO3/L) and low total hardness values (11.5 to 51.2 mgCaCO3/L) which indicate that the river water is black and soft. There was significant (p~,0.05) seasonal variation in temperature (23.1 to 31.7~'C\}, Secchi transparency (9.30 to 19.00 cm), total hardness (11.5 to 51.2 mgCaCO3/L), dissolved oxygen (5.20 to 7.50 mg/L) and dissolved oxygen deficit (0.02 to 2.95mg/L). These results are useful for several stake holders who use the river as a sink for trade wastes, as source of water for fish farming, as source of broodstocks of Chrysichthys nigrodigitatus, as raw water for water treatment plants, and as means of transportation of industrial materials

Economics of trickling biological periwinkle shell filter for closed recirculating system

Studies on the economics of trickling biological periwinkle shells filter for closed recirculating catfish system was carried out at the University of Science and Technology, Port Harcourt, Nigeria for 12 weeks. The periwinkle shells biofilter and other recirculating aquaculture system (RAS) components were designed and set up for a pilot catfish production using Clarias gariepinus juveniles at the stocking density of 400 fish/m3. Using fish holding tank volume of 0.21m3, biofilter volume of 1m3, sedimentation tank volume and flow rate of 4.20m3 and 0.78m3/hr respectively, lift pump flow rate of 2.10m3/hr, and an annual production of 3 tons of catfish, a record of all financial expenditures was kept. The financial analyses of the system with periwinkle shells filter and that of imported plastic filter block of same size were prepared. The discounted cash flow projections for the two systems were also prepared. From the discounted cash flows, the economic viability indices for the two systems were computed. The economic analysis compared the profitability index of 1.45 and the payback period of 2.50 years for the system with periwinkle shells filter to the profitability index of 0.60 and payback period of 5.90 years for the imported plastic filter block, and concluded that the system with periwinkle shell filter was cheaper and more cost effectiv

The influence of stocking density on the growth performance and production of tilapia (Oreochromis niloticus) in earthen pond

An experiment was carried out to investigate the influence of stocking density on the growth of the initial stocked tilapia (O.niloticus) in earthen ponds, the effect on the reproductive performance of the fish and impact on the economy of production. Six African Regional Aquaculture Centre (ARAC), Aluu, Port Harcourt earthen genetic ponds split into three compartments representing three replicates were stocked with 666 fingerlings of 4.33g average initial weight and 6.06cm average initial length at 37 per replicate. They were fed with a 28%CP blood meal based diet for nine months. The size of the ponds and depth of water was such as to attain average stocking densities of 6.33, 6.45, 5.05, 3.60, 2.88 and 2.05 fish/m3. The result showed distinct increase in growth as the stocking densities decreased. Ponds 5,6 and 4 with lower densities 2.88, 2.05 and 3.60 fish/m3 having higher final weights of 146.10, 120.79 and 108.69g than ponds 3, 2 and 1 with 85.37, 74.36 and 59.68g respectively (P<0.05). Average final length was higher in ponds 5, 6 and 4 at 14.46, 13.86 and 13.79cm than ponds 3, 2 and 1 with 12.09, 10.62 and 11.36cm. Relative weight gain followed suit with 3274.13, 2689.61 and 2410.16% in ponds 5, 6 and 4 as against 1871.59, 1617.32 and 1277.83% in 3, 2 and 1. Percentage survival increased as stocking density decreased at 28.18, 35.45, 37.27, 40.91, 41.82 and 45.45% for the 6.33, 6.45, 5.05 , 3.60, 2.05 and 2.88 fish/m3 treatment respectively, with the 3.60, 2.05 and 2.88fish/m3 treatment significantly higher (P<0.05). The 2.88fish/m3treatment (treatment 5) also provided the cheapest cost of producing 1kg of fish at N178.74 as against N457.14, N351.44, N312.41, N242.81 and N217.25 per kg fish of treatments 1, 2, 3, 4 and 6 respectively. The total number of off-springs produced all in progressive sizes increased as the stocking density decreased at 1530, 1636, 1674, 2053, 3160 and 3234 for ponds 1-6. The experiment showed that tilapia fingerlings stocked in earthen pond at low densities grow and reproduce more and at a lower cost of production than those with higher stocking densities. The ideal appears to be between 2 and 3 fish/m

AQUACUALTURE PROJECT PLANNING AND APPRAISAL

This study reviews the role of aquaculture project planning and appraisal in Nigeria’s fisheries and aquaculture sub-sector as part of the larger effort in the quest for food fish security in Nigeria. The focus was on human capacity building in the subject matter. There is a great need for the development of local capacity on small-scale, medium-scale and large-scale project formulation and appraisal even at undergraduate level to realize and sustain the set target in the fishery sub sector of the Agricultural Transformation Agenda (ATA) of present administration in view of the fast growing aquaculture industry in Nigeria. The important roles of project planning and appraisal techniques as vital stages in the development of aquaculture projects are reviewed under the following sub-headings: the link between projects and national development plans, the nature and characteristics of aquaculture projects, types of aquaculture projects, project sequence and cycle, project appraisal, and so on. The main aim is to ensure that, as its contribution to overall nation