West African Journal of Applied Ecology

Aspects of the Feeding Ecology of Some Selected Fish Species Assemblages of an Estuarine Mangrove Ecosystem in Ghana

2025-07-07T13:46:51+00:00

Food and feeding habits of commercial fish species from Kakum River Estuary and Benya Lagoon were studied purposely to assess the range of food items available to the species in the brackish ecosystems. The quality of naturally available food resources within a brackish ecosystem influences the feeding habits of fish. Fish samples for the study were obtained with a cast net and were examined employing the frequency of occurrence method. The diet of the species from both the estuary and the lagoon were similar, with minor dissimilarities in the proportions of the recorded food items. While diatom, zooplankton, sand particles, detritus, and polychaetes occurred to be the most essential food items for grey mullets (Mugilidae) from the estuary, blue-green algae, polychaetes, and detritus was the preferred food for the species in the lagoon. The core feeding cycle of grey mullets in the Kakum River Estuary occurred during the diurnal period between the hours of 14:00 GMT and 18:00 GMT for all sampling dates. There was not much or no feeding during the nocturnal period except Mugil curema which feeding activity peaked at 2:00 GMT sampling. The peak feeding activity for Liza dumerilli, Liza falcipinnis, Mugil bananensis, and Mugil curema occurred at 14:00 GMT and 18:00 GMT while the peak feeding activity for Mugil cephalus occurred at 18:00 GMT during the day for all the sampling dates. Liza dumerilli, Mugil cephalus, and Liza falcipinnis occurred to be species with high feeding intensity at low tides.

Participatory rural appraisal to identify farmer-preferred soybean traits in Ghana

2025-07-07T15:00:29+00:00

Soybean pod shattering remains an important constraint in soybean cultivation causing yield loss up to 100%. The objective of this study was to identify the varieties as well as the plant and grain traits of soybean preferred by farmers. A survey was conducted in three northern (Northern, Upper east and west) regions of Ghana. A total of 192 farmers were reached and individual farmers were interviewed using structured questionnaire. The data collected was coded using a statistical software. Descriptive analyses were used to summarize the data into means, percentages and tabulations. Kendall Coefficient of Concordance procedure was implemented to ascertain the level of agreement among farmer preferred soybean traits. The study revealed that, despite the existence of pod shattering resistant varieties, many farmers still grow pod shattering susceptible varieties. They preferred these varieties because they were high yielding (Salintuya-I), early maturing (Sounpungun), and a trap crop for striga (Songda). The majority of farmers (98%) ranked yield (3.79), big seed size (4.03) and non-shattering (4.08) as the most important traits (Kendall’s W=0.379 P=00.00) across all regions. In addition, early maturing (4.45) and medium maturing varieties (4.45) were also ranked as important traits by all respondents. Therefore, breeding programmes should aim to develop varieties, taking into consideration farmer preferred traits to increase varietal adoption.

Can soil amendment with or without fertiliser benefit the soil and upland rice?

2025-07-07T16:21:52+00:00

Crop production is being threatened by poor soil quality and nutrient loss. An avenue to enhance soil quality for sustainable crop production is to explore the appropriate soil amendment with or without chemical fertiliser. A pot experiment was used to investigate the effects of biochar at 5tha^-1(BC5), sawdust at 5tha^-1(SD5), biochar at 5tha^-1with fertiliser (BC5-F), sawdust at 5tha^-1with fertiliser (SD5-F), biochar at 50t ha^-1(BC50), sawdust at 50tha^-1 (SD50), biochar at 50tha^-1with fertiliser (BC50-F), sawdust at 50tha^-1 with fertiliser (SD50-F) and control on soil quality, growth, and yield of upland rice. BC50-F or BC50 increased the soil pH, but SD5-F reduced the soil pH. Also, SD50-F or SD50 enhanced soil organic carbon and total nitrogen. The BC50, BC5-F and SD5-F treatments enhanced available P in Akim Oda soil (Ferric Acrisol). In the Winneba soils (Haplic Lixisol), all treatments enhanced available P except SD5. Furthermore, all treatments with fertiliser enhanced rice tiller numbers and plant height in Akim Oda, except BC50, which decreased height. Compared to the Winneba soil, BC5-F and SD5-F enhanced rice tiller numbers. However, plant height was maintained for all treatments except for BC50-F. Similarly, straw yield in the Akim Oda and Winneba soils was improved by all treatments except BC50-F in Winneba soil. Grain yield in the Akim Oda soil was enhanced in BC50-F, SD50-F and SD5-F, but only in SD50-F for Winneba soil. Biochar or sawdust with inorganic fertiliser could enhance soil properties and crop yield, depending on the soil type.

Comparison of leaf mineral content and soil nutrient status and their combined effect as predictors of cocoa (Theobroma cacao L.) bean yield

2025-07-07T16:32:10+00:00

There is a dearth of research focusing on predicting cocoa bean yield using soil nutrients and/or leaf mineral content, even though such yield predictions exist for other crops. The study examined the relationship between soil nutrients, cocoa leaf mineral content, and yield. A progeny trial field in Bunso with two cocoa varieties and thirty stands was selected from three plots. Sixty pairs of soil samples were taken from the surface and subsurface within a two-meter rhizosphere diameter. Four fully expanded young leaves were sampled from each selected tree three times during the season. Both the soils and leaves were analyzed for nutrient content. The results indicated low correlation coefficients between the soil and the leaf nutrients. The separate multiple regression of the nutrient content of surface soils against pod number, the subsurface soil nutrients against the pod number, and the leaf nutrient against the pod number all recorded low significance (p < 0.05) R²(0.32, 0.36, and 0.20, respectively). However, when soil nutrients at each depth were combined separately with leaf nutrients and regressed against the pod number, relatively greater R² values were recorded (0.61 and 0.57, respectively). The combined soil and leaf nutrient content at each depth was a better predictor of yield than using them separately. Soil nutrients were found to have a better relationship with yield than their leaf counterparts. It was also found that the ideal time for soil and/or leaf sampling is at the onset of the rainfall.

Assessing gender and geospatial factors impacting cocoa productivity in Ghana’s organic and conventional agroforestry systems

2025-07-07T16:53:00+00:00

Understanding geospatial and gender dynamics of farm productivity is crucial for addressing inequities in the development of cocoa (Theobroma cacao L.) agroforestry support services. Cocoa agroforestry systems (CAS) play a vital role in mitigating deforestation, soil degradation, and the negative impacts of climate change on sustainable agriculture. However, there is a lack of information on the spatial distribution of cocoa farms and the gender dimensions of land productivity in organic and conventional CAS, which hinders equitable access to development support. This study examines the spatial and gender dynamics of organic cocoa (OC) and conventional cocoa (CC) farm productivity to promote fair distribution of resources and development support within CAS in Ghana. A multi-stage sampling method was employed across three soil types—ferralsols, lixisols, and leptosols in selected agroecological zones. Eleven (11) CC and 11 OC farms were randomly selected for each soil type. Data collected included cocoa farm sizes, farm polygons, yields, gender, and socioeconomic attributes of the farmers. The results revealed that OC and CC farms were spatially dispersed. Characterization of the farmers' socioeconomic data showed significant gender disparities, with male dominance in cocoa farm ownership. Despite these disparities, female cocoa farmers who own their lands demonstrated higher soil organic carbon conservation and cocoa productivity than male farmers. These findings suggest that spatial clustering of cocoa farms and gender equity are needed to enhance the delivery of development support, helping to achieve the 2030 Sustainable Development Goals (SDG), particularly women's empowerment (SDG 5) to promote sustainable agriculture (SDG 2). In addition to gender equality, spatial clustering and connectivity of CAS are environmentally sound for conserving life on land (SDG 15), boosting efficient support partnerships (SDG 17) and tackling climate change (SDG 13).

Proximate Composition and Heavy Metal Content of Commercial Tilapia Starter Feeds Sold at Asuogyaman Municipality, Ghana

2025-07-07T17:05:13+00:00

One of the main requirements for sustained aquaculture is high-quality fish feed. The quality of fish flesh, including shelf life, appearance, flavour, colour, and nutritional value, is determined by the feed quality. Consumers today are highly concerned about several issues related to fish farming practices and the different materials used in producing fish feed. The primary objective of the present investigation was to evaluate the proximate composition (protein, lipid, moisture, ash, carbohydrate, and crude fibre) and levels of heavy metals (Cr, Pb, Cd, Zn, and Cu) in selected commercial tilapia starter feeds available in Ghana. There were no significant variations between the nutritional content offered by feed firms and the values identified in this analysis. However, the derived proximate values for the study were lower compared to the feed manufacturers. The findings revealed the presence of different heavy metals in the feeds at varying levels. Chromium (Cr), lead (Pb), cadmium (Cd), zinc (Zn), and copper (Cu) were the heavy metals with the highest levels (mg/kg), with values of 0.544, 0.141, 0.020, 1.821, and 7.758, respectively. The concentration of chromium (Cr) in the current study exceeds the maximum allowable limits of 0.05 mg/kg set by international organisations, which may be detrimental to the fish's health. The study suggests that commercial fish feed producers take the necessary precautions to guarantee the nutritional integrity of their products and prevent heavy metal contamination. Otherwise, the final consumers—humans and fish—might be more susceptible to accumulating and assimilating the heavy metals, which could have health implications.

Can feeding dried browse leaves to sheep reduce methane emissions and improve weight gain?

2025-07-07T17:41:41+00:00

It is important to evaluate whether a specific browse leaf will be able to reduce methane emissions as well as improve weight gain before recommending it to farmers. Therefore, the objective of this study was to determine performance, methane emission and amplification of methanogens and protozoa of sheep fed four different dried browse leaves. Sixteen forest-type ram lambs of 14.38±0.51 kg average weight were used. The animals were fed four dried browse leaves [Albizzia lebbek (AL), Gliricidia sepium (GS), Moringa oleifera (MO) and Millettia thonningii (MT)] for six weeks. Genomic DNAs were extracted from methanogen and protozoa strains obtained from rumen fluid and sheep faeces using Quick-DNA™ Fecal/Soil Microbe Miniprep Kit. Sheep fed AL, MO and MT responded by gaining weight but those fed GS lost weight with time. All four browse leaves fed produced low methane and the trend of methane emission was relatively stable. Detecting methanogens and protozoa in the rumen fluid and faeces of sheep is an indication that the browse leaves were able to inhibit the activities of methanogens and protozoa in the rumen and eliminated them through faeces. Therefore, AL, MO and MT can improve weight gain and reduce methane emission while GS can minimise methane emission but cannot improve weight gain. This study highlights the contribution of natural resources to climate-smart approaches in sheep production and reduction of enteric methane production hence minimising the effects of climate change.

Enteric Bacteria and Helminths in Rattus rattus in Tema Community One Market: Potential for Zoonotic Disease Transmission

2025-07-07T17:47:56+00:00

Rattus rattus is a significant pest in urban settings and also acts as reservoir host for zoonotic diseases, posing public health challenges. The abundance of R. rattus in the urban environment, due to ample food and availability of shelter, makes them significant potential reservoir hosts and vectors of diseases. This study aimed to investigate the prevalence of enteric helminth and bacteria in R. rattus in Tema Community One market, Ghana, and to assess the potential for transmission of zoonotic diseases. Zinc Sulphate flotation method was used for the parasitological examination. Conventional technique of bacterial culture and standard biochemical tests were used for the identification and characterization of bacterial isolates. Out of the 30 rats examined, 93.3% (28/30) were infected with at least one helminth. Helminth genera identified were Hymenolepis, Strongyloides, Taenia, Moniezia, Toxocara, Enterobius, Ascaris, Capillaria, Fasciola, and Trichostrongyle-type. The most common helminth was Hymenolepis spp. (80%), including H. nana (33.3%) and H. diminuta (50.0%). Additionally, 76.7% (23/30) of the rats harboured three or more parasite genera, and 50.0% (15/30) were infected with at least four different parasite species. Generally, infections were of low to moderate intensity, except for Hymenolepis spp., which showed high (501-2000 EPG) to very high (> 2000 EPG) intensity in a significant proportion of the rats. The most common enteric bacterium identified in the rats was Escherichia coli (86.7%), followed by Serratia marcescens (83.3%), Proteus mirabilis (76.7%), and Salmonella spp. (66.6%). Variations in the frequency of helminth and bacterial infections were observed among the rats. The study highlights the significant prevalence of pathogenic enteric bacteria and helminths in R. rattus populations in the Tema Community One market and indicates a potential for zoonotic disease transmission.