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The study of feeding ecology and reproductive biology ensures that the right management measures are applied for best output of fish stocks. Selection of good fish species for culture is also made possible through feeding and reproductive studies. Ghana over-relies on the culture of Nile tilapia and African catfish because there is no reliable scientific information on potential fish species that can be included for fish farming. The current study sought to investigate food habits and reproductive characteristics of economically important fish species in the Tono Reservoir of Northern Ghana. Monthly sampling was carried out from January, 2015 to December, 2016 (24 months). Specimens were obtained using cast net and gillnets of varying mesh sizes. Specimens were immediately transported to the laboratory in a chilled iced chest of temperature 4 ◦ C for morphometric measurements and microscopic analysis of gut content and gonads. Thirty-three (33) individual food items were identified from all the fish species. Phytoplankton was the most important diet (Index of Relative Importance, IRI = 1923) whereas zooplankton was the least important diet (IRI = 35) out of the five major categories of food items identified from all the fish species. The major peaks of gonadosomatic index (GSI) of females were noted in February – March and June – July. Over 80 % variation of fecundity was explained by the predictors (standard length, fish weight and gonad weight) for Clarias gariepinus and Auchenoglanis occidentalis. All the fish species were classified as omnivores and they spawned more than once in a year making all of them good candidates for aquaculture. Management measures should focus on regulating agricultural activities close to the reservoir and fishing activities in the reservoir for sustainable fish production and exploitation.
Palynofacies analyses from Bonyere Well No. 1 in the Tano basin, western Ghana has revealed five palynofacies associations (I – V) based on the percentage relative abundances of the sedimentary organic matter (SOM). The palynofacies associations reflect deposition in a fluvio-deltaic (oxic) environment, a distal dysoxic-anoxic shelf environment, a proximal dysoxic-suboxic environment, nearshore (oxic) and a fluvio-deltaic/nearshore environment with high oxygen levels and low preservation rates respectively. Based on marker palynomorphs, Campanian – Maastrichtian age has been assigned to sediments within the interval (1800-10 ft) – (90-100 ft), Turonian – Lower Senonian (Santonian) age between (3160-70 ft) – (1980-90 ft) and Aptian age between the interval (8140-50 ft) – (3340-50 ft). The absence of the elater-bearing pollen which are typical Africa-South America (ASA) elements for the Albian – Cenomanian age is indicative of an unconformity between the Aptian and Turonian sediments.
Integrated soil nutrient management is required to increase and sustain agricultural productivity. Assessment of soil, organic matter and nutrient losses was carried out in a 3-year integrated maize cropping system in Ghana. The treatments: no-till (NT), minimum tillage (MT), conventional tillage (CT) and soil amendments (Control, NPK, poultry manure and their combination), were arranged in a factorial design. The results showed soil loss to range from 0.140- 4.907 Mg·haˉ¹ in the order of NT < MT < CT < Bare. Soil loss reduction over the Bare was 88% by ½ Rates of NPK+PM, 87% by PM and 85% by NPK. Soil depth reductions in NT and MT were 92% lower than in CT. The loss of organic matter ranged from 47.6 kg·haˉ¹ to 120.70 kg/ha and was in the order of Bare > CT > MT > NT. Nutrient losses followed the same trend. Losses in soil organic matter, N, P, K, Ca, Mg and Na under tillage x soil amendments interactions were higher in the CT and bare plots. NT and MT, which were recognised as conservation tillage systems, amended with combination of organic and mineral fertilisers were found as better options in minimising soil quality degradation.
This study explores the determinants of food expenditures in northern Ghana’s rural households, using a survey data collected in 2010 in the vicinity of Tamale, the capital of the Northern Region. Three estimation methods (OLS, OLS with robust error, and WLS) are used in empirical models to address the possible heteroscedasticity. Models indicate that socio-demographic factors such as income, owning a tractor, age, and household composition are important factors in determining food expenditure. Similarly, farm features such as cultivation of staple or cash crops, the field size of groundnuts, as well as buying dry goods in bulk are also found to be major determinants. Results provide useful information for both private and public sector decision makers, while supplying ample evidence of the importance of estimation method selection to generate most accurate quantified effects of individual explanatory variables on food expenditure.
A new Mesocyclops species, M. bosumtwii, is described from Lake Bosumtwi, Ghana. It is proposed that M. bosumtwii belongs to the Madagascar-African “major-pilosus-insulensis species group”. A key for African species of the genus Mesocyclops is proposed.
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