West African Journal of Applied Ecology最新文献

{"title":"Water quality characteristics at the estuary of Korle Lagoon in Ghana","authors":"A. Karikari, K. Asante, C. Biney","doi":"10.4314/WAJAE.V10I1.45700","DOIUrl":"https://doi.org/10.4314/WAJAE.V10I1.45700","url":null,"abstract":"The Korle lagoon is a major run-off water receptacle and outlet from the city of Accra into the Gulf of Guinea. Uncontrolled discharges of domestic wastes and industrial effluents as well as raw sewage (which are washed into the lagoon during high tides), have led to its environment being seriously degraded. Physico-chemical and bacteriological studies were conducted to measure the concentration of pollutants at the entrance of the Korle lagoon, from the offshore of the lagoon and from the raw sewage discharged onto the beach at neap and spring tides. Physical characteristics of the lagoon waters, such as pH and temperature, for the two tides did not show any large variations and were fairly comparable. Salinity, suspended solids and conductivity, however, varied significantly with tidal changes. Dissolved oxygen was extremely low at low tide as a result of large quantities of waste materials from domestic and industrial activities which reach the lagoon. This was also evidenced in high biochemical oxygen demand (BOD) as well as high faecal coliforms during neap tide. Changes in the concentrations of nutrients occurred with changes in tide; these being high, especially at high tide when sewage is back-washed into the lagoon. The study indicated that the entrance of the Korle lagoon to the sea and the adjacent sewage outfall area were polluted and not suitable for primary or secondary contact due to the occurrence of large numbers of coliform bacterial. However, the offshore area showed good water quality.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"10 1","pages":"73-85"},"PeriodicalIF":0.0,"publicationDate":"2009-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V10I1.45700","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70684158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Concentration of trace metals in boreholes in the Ankobra Basin, Ghan","authors":"Bk Kortatsi","doi":"10.4314/WAJAE.V10I1.45706","DOIUrl":"https://doi.org/10.4314/WAJAE.V10I1.45706","url":null,"abstract":"Analysis of trace metals in groundwater from the Ankobra basin revealed high levels of iron, manganese and aluminium. Approximately 40% of boreholes had total iron concentration exceeding 1000 mg l-1 (maximum WHO permissible limit). Aluminium concentration varied from 0.1 mg l-1 to 2510 mg l-1 with a median value of 10.0 mg l-1.Approximately 20% of the boreholes had aluminium concentration exceeding the WHO maximum acceptable limit (200 mg l-1) for drinking water. Manganese concentration was in the range 6–2510 mg l-1 with a median of 356 mg l-1. Roughly 25% of the boreholes had manganese concentration higher than 500 mg l-1, which is the WHO maximum acceptable limit for drinking water. The concentration of mercury was higher than 1.0 mg l-1 (WHO maximum acceptable limit) in 60% of the boreholes during the rainy season but below detection limit in the dry season, suggesting anthropogenic origin for mercury in the groundwater. Other trace metals that occurred, but in insignificant concentration in boreholes, include lead, arsenic, nickel and selenium. Most of the boreholes with high trace metal concentrations were located in and around the Bawdie-Bogoso-Prestea area.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"1 1","pages":"101-118"},"PeriodicalIF":0.0,"publicationDate":"2009-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V10I1.45706","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70684599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trace metal Contamination in Water from abandoned mining and non-mining areas in the Northern Parts of the Ashanti Gold Belt, Ghana","authors":"C. Tay, Fátima Momade","doi":"10.4314/WAJAE.V10I1.45714","DOIUrl":"https://doi.org/10.4314/WAJAE.V10I1.45714","url":null,"abstract":"A survey was conducted on the levels of trace metals (Ni, Cu, Hg, Pb, Mn, Fe, Zn, Cr, Cd, Mg and Ca) in ground and surface water sources from the northern parts of the Ashanti gold belt. Water samples were collected from 67 boreholes, 24 wells, and 10 streams during dry and wet seasons for trace metal analyses using Philips PU 9200 atomic absorption spectrophotometer. The main objective was to determine whether trace metal contamination in the study area was as a result of mining or geochemical and biochemical processes within the aquifer. The results showed that ground water (pH range 4.09–7.29 and mean 5.87 pH units) was slightly acidic (low pH) than surface water (pH range 5.81–7.74 and mean 7.12 pH units). The ground waters (with conductivity range 96–1553 mS/cm and mean 407.7 mS/cm) in the study area were also more mineralized than surface waters (with conductivity range 113–540 mS/cm and mean 323.30 mS/cm). Correlations between the trace metals revealed expected process-based relationship between Mg2+ and Ca2+ (r = 0.76), derived mainly from the geochemical and biochemical processes within the aquifer. However, there were also other strong linear relationships between trace metals, such as Fe2+ and Ca2+ (r = 0.61); Mg2+ and Mn2+ (r = 0.72), Hg2+ and Mn2+ (r = 0.61), that are not normally expected to be linked in terms of processes. All the well and stream water sources had one or more trace metal level outside acceptable limits set by the World Health Organization for drinking water, and only three borehole water samples at Konongo (Abronikrom), Ntronang (Ahenbronoso) and Bomfa (Nkubem) were safe for human consumption","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"10 1","pages":"127-142"},"PeriodicalIF":0.0,"publicationDate":"2009-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V10I1.45714","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70684324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Food and feeding habit of Sarotherodon melanotheron , Rüppell, 1852 (Pisces: Cichlidae) in Sakumo Lagoon, Ghana","authors":"P. Ofori-Danson, G. Kumi","doi":"10.4314/WAJAE.V10I1.45692","DOIUrl":"https://doi.org/10.4314/WAJAE.V10I1.45692","url":null,"abstract":"An investigation was conducted into the food and feeding habits of the blackchin tilapia Sarotherodon melanotheron (Ruppell, 1852) in the Sakumo lagoon in the Greater-Accra Region of Ghana. The food items covered a wide range of plankton and other accessory prey items suggesting that the fish is largely planktivorous. There were no clear differences among food items eaten by the juveniles and adults, with the Shannon-Wiener diversity index (H’) being 1.1 and 1.2, respectively. This suggests that the diversity of food items exploited by the adults are similar to that of the juveniles, or that they exploited the same microhabitats. However, the juvenile fish had preference for the Cyanophyceae, Chlorophyceae and Rotifera, whilst the adults generally preferred Cladocera, Bacillariophyceae and Cyanophyceae, suggesting age-specific dietary preference. The majority (45.2%) S. melanotheron had 3/4 fullness of guts around 1200 GMT and between 1500–1800 GMT (40.5%), suggesting that the fish probably feeds mostly at this time during the day, even though the fish is known to feed largely in the night to avoid predatory birds. The greatest number of empty guts (90%) was observed between 0600–0900 GMT, suggesting that they probably reduce feeding during this period of the day. The ability of S. melanotheron to feed at different trophic levels, coupled with the potential for fast growth, makes this species a promising candidate for incorporation into locally-operated polyculture systems with minimal inputs of expensive animal protein in the feed.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"10 1","pages":"21-33"},"PeriodicalIF":0.0,"publicationDate":"2009-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V10I1.45692","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70683944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of sediment yield in runoff from agricultural land in the Southern Guinea Savanna Zone of Nigeria","authors":"N. Egharevba, H. Ibrahim","doi":"10.4314/WAJAE.V10I1.45709","DOIUrl":"https://doi.org/10.4314/WAJAE.V10I1.45709","url":null,"abstract":"Records on 111 natural rainfall events covering 2 years (2001 and 2003) were used to estimate the sediment yield in runoff from a bare surface Alfisol, and a similar soil under straw mulch and natural grass in the southern Guinea savanna zone of Nigeria. Measurements of runoff amount and sediment load were made for the months of May–September of each year. The mean monthly runoff amount for the straw mulch, grass and the bare plots were 21.5 mm,50.3 mm and 64.1 mm, respectively. The mean sediment load from the straw mulch and grass plots were 0.23 t/ha and 0.5 t/ha, respectively. The corresponding monthly mean sediment yield of 1.64 t/ha from the bare plot was 2.8 and 7.5 times greater than the grass and straw mulch plot, respectively, indicating the effectiveness of the latter in reducing splash erosion. The sediment yield was regressed on the runoff depth and the rainfall amount to obtain linear relationthat can be used to predict sediment yield on Alfisols under bare farm land environment.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"10 1","pages":"131-138"},"PeriodicalIF":0.0,"publicationDate":"2009-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V10I1.45709","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70684160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution characteristics of mineral elements in tree Species from two contrasting secondary forests in Ghana","authors":"E. Owusu-Sekyere, J. Cobbina, T. Wakatsuki","doi":"10.4314/WAJAE.V10I1.45710","DOIUrl":"https://doi.org/10.4314/WAJAE.V10I1.45710","url":null,"abstract":"Tree species in two contrasting forests were evaluated on three plots of 0-19 ha (0.57 ha) in each secondary forest. Tree species populations were 44 in Akyaakrom (AS), 29 in Dopiri (DS), and families were 18 in AS and 16 in DS. Tree densities were 121 and 99 in AS and DS, respectively, in 0.57 ha. In terms of tree species population, diversity and density, AS was superior to DS. The distribution of major mineral elements in the leaves showed mean concentrations in decreasing order of K > Ca > Mg > P > N in AS and Ca > K > Mg > P > N for DS. The bark samples showed concentrations in decreasing order of Ca > K > Mg > N > P in both forests. Generally, concentrations of Ca in the tree species bark samples of both forests were about three times higher than they were in the leaves. Soil nutrients showed that Ca, Mg and N concentrations were higher in the DS than in AS within 0-60 cm soil depths. However, at 30-45 cm depth, Ca, Mg, K and N concentrations were higher in AS than in DS. The nutrient element concentrations were high at 0-15 cm than further down the soil depths for the two forests. The land quality indexes of the principal nutrients N, P, K, Ca and Mg were higher in AS than in DS. Thus, eight tree families in AS and five in DS, and tree species numbers 23 and 12 were peculiar to each site. This may suggest the higher tree population and diversity recorded for AS than for DS.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"10 1","pages":"139-152"},"PeriodicalIF":0.0,"publicationDate":"2009-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V10I1.45710","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70684173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phosphate rock dissolution and availability in some soils of semi-deciduous Rainforest Zone of Ghana","authors":"S. Asomaning, M. Abekoe, E. Owusu-bennoah","doi":"10.4314/WAJAE.V10I1.45715","DOIUrl":"https://doi.org/10.4314/WAJAE.V10I1.45715","url":null,"abstract":"Alfisols and Ultisols of the semi-deciduous forest zone of Ghana are known to be moderately acid and very low in plant available phosphorus (P). These soils need to be fertilized to increase crop production but due to economic reasons local farmers are unable to afford water-soluble P fertilizers. Instead of expensive superphosphates, the use of less expensive phosphate rocks such as Togo rock phosphate (TRP), Gafsa rock phosphate (GRP) and 50% partially acidulated rock phosphate (PAPR) are possible alternative P sources for these soils. The rate of dissolution of TRP, GRP, PAPR and TSP in three benchmark soils of Ghana was assessed, and the effectiveness of these P sources determined in a greenhouse using maize (Zea mays var. Toxpino) as a test crop. The dissolution of the P sources in three soils Bekwai, Nzima (Ultisols) and Kokofu (Alfisol) along a toposequence was investigated in an incubation study and also in a greenhouse experiment. The rate of dissolution of the P fertilizers was determined in the laboratory by extracting with anion exchange resin membrane (AEM), 0.1M NaOH and 1M HCl at 21 days interval for 105 days. In the greenhouse study, each P source was added at the rate of 60 mg P kg-1 soil, and sown to maize (Zea mays. var.Toxpino) for 28 days. The results of the incubation study showed that the amount of P extracted by the AEM and HCl, following the addition of the P sources, decreased with incubation time in all three soils. However, there was an increase in NaOH-P in all the three soils as incubation progressed. The increase in the NaOH-P suggested that the dissolved P was adsorbed by Fe and Al oxides. The greenhouse results showed that dry matter yield was in the order TSP = PAPR > GRP > TRP. Relative to TRP, the PAPR and GRP were reactive enough to provide plant available P to satisfy the early P requirement for maize growth. Togo PR has little potential for direct application in the three soils.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"10 1","pages":"209-220"},"PeriodicalIF":0.0,"publicationDate":"2009-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V10I1.45715","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70684364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The dilemmas of plastic wastes in a developing economy: Proposals for a sustainable management approach for Ghana","authors":"J. Fobil, J. Hogarh","doi":"10.4314/WAJAE.V10I1.45716","DOIUrl":"https://doi.org/10.4314/WAJAE.V10I1.45716","url":null,"abstract":"Plastics have been used extensively in both food and water packaging because of their inherent properties such as low bulk densities and inertness that make them convenient carrier materials and low risk contaminants. Plastic bottles and sachets used to package iced water that is sold to people in transit points and in moving vehicles have become widespread in the sub-region. However, the packaging revolution has not been correspondingly backed by appropriate plastic waste management policy, which has left many cities in sub-Sahara Africa littered with plastic wastes; thus, creating disgusting visual nuisances and other public health problems. The paper discusses the experiences, challenges and prospects of plastic waste management schemes in Ghana and proposes a new model of fractional levy and polluter tax system to address this environmental eye sore. It is concluded that the current rate of environmental deterioration is likely to persist unless a long term remedial such as the polluter taxation system is carefully worked into plastic wastes management schemes in the region.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"462 1","pages":"221-229"},"PeriodicalIF":0.0,"publicationDate":"2009-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V10I1.45716","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70684374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bio-recovery of N and P from an anaerobic digester effluent: The potential of duckweed ( Lemna minor )","authors":"E. Abuaku, K. Frimpong, B. Osei, W. Verstraete","doi":"10.4314/WAJAE.V10I1.45711","DOIUrl":"https://doi.org/10.4314/WAJAE.V10I1.45711","url":null,"abstract":"The possibility of growing duckweed (Lemna minor) on anaerobic digester effluent and its nitrogen and phosphorus acquisition potential was studied. Duckweed was cultured for 21 days on an anaerobic digester effluent using two methods: static aeration (SAT) and normal batch reactor (NBR) techniques, respectively. The treatments involved pure effluent and 1/10, 1/25 and 1/50 effluent dilutions, respectively. Fifty duckweed fronds were grown in the anaerobic digester effluent for 21 days. At the end of the growth period, phosphate levels, total ammonium nitrogen (TAN) and total oxidized nitrogen (TON) contents of the growth media were determined. Total nitrogen concentration and orthophosphate P content in the duckweed were also determined. The results obtained indicated that duckweed was capable of growing on the anaerobic digester effluent provided its TAN content did not exceed 42 mg N l-1. Nitrogen uptake by the duckweed from the effluent ranged between 53 and 115.7 mg l-1 whereas P uptake varied from 1.40 to 8.4 mg P l-1. The relative growth rate of duckweed in the anaerobic digester effluent was observed to be comparable to literature value of 0.22 mg day -1. The results have demonstrated that duckweed has the potential to recover N and P from anaerobic digester effluent.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"10 1","pages":"153-162"},"PeriodicalIF":0.0,"publicationDate":"2009-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V10I1.45711","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70684186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of pretreatments on seed viability during fruit development of two varieties of Irvingia gabonensis","authors":"Pj Nya, D. Omokaro, A. Nkang","doi":"10.4314/WAJAE.V10I1.45712","DOIUrl":"https://doi.org/10.4314/WAJAE.V10I1.45712","url":null,"abstract":"Studies to identify the stage at which developing fruits of Irvingia gabonensis (var. excelsa and var. gabonensis), picked from standing trees and/or forest floors, attain maximum viability and germinability were conducted in two harvesting seasons in 2000 and 2001. Some pretreatment methods were used as a means of stimulating expression of maximum germinability as source of seeds for seedling production. The moisture contents of whole seeds decreased steadily and significantly (P = 0.05) throughout the developmental stages of both varieties and in both harvests. Seeds harvested from standing trees and forest floors, pretreated by steeping in water for 24 h at 26 oC and sown in sawdust and petri dishes on moist filter paper, gave 80% germination in variety gabonensis, 20 weeks after fruiting. Germination potentials of seeds in both harvests were enhanced significantly (P = 0.05) with seeds pretreated by steeping in water for 24 h at 26 oC, and sown in sawdust and petri dishes on moist filter paper by as much as 60% and 80% for var. excelsa and var. gabonensis, respectively, in the developmental stages, 14–20 weeks after fruiting with significant (P = 0.05) decrease in germination time to 21 and 15 days, respectively. There was also significant (P = 0.05) relationship between viability and germination in both harvests and in the two varieties throughout the developmental stages. Potassium nitrate (KNO3) significantly (P = 0.05) enhanced germination potentials of the seeds over the control when soaked in 1.5 g/l concentration in both varieties and in the two harvests (18–20 WAF) by 80%. Mannitol significantly (P = 0.05) reduced germination potential (40%) of the seeds with increased germination time in both harvests and in the two varieties throughout the developmental stages. There was a high significant (P = 0.05) increase in germination potential (60%) of seeds treated with polyethylene glycol (PEG) when soaked in concentration of 10 g/l for 48 and 72 h in both varieties and in the two harvests (18–20 WAF). The study shows that the fruits of I. gabonensis assume ripening characteristics (yellowing) and that the viable seeds can be obtained from standing trees and/or picked from forest floors from the 12th to 20th week after fruiting.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"10 1","pages":"163-176"},"PeriodicalIF":0.0,"publicationDate":"2009-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V10I1.45712","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70684264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}