Fosu Lagoon Research Articles

Sediments Composition and Morphology of the Fosu Lagoon Barrier Beach, Bakaano, Cape Coast, Ghana

This research examined the Fosu Lagoon Barrier Beach sediment composition at Bakaano in the Cape Coast Metropolis. The researchers focused on the physical attributes of the Fosu Lagoon Barrier Beach at Bakaano in Cape Coast and analysed its sediment composition. The paper analysed twelve (12) samples or specimens of soils/sediments at the laboratory to determine the sediment composition of the barrier beach. The physical dimensions of the barrier beach were measured in the field with a tape measure and a Global Positioning System (GPS). The study established that the Fosu Lagoon Barrier Beach is approximately 130m long and 58m wide. It is shallow in height, about 10m above sea level and composed mainly of coarse sand particles. The granulated sand composition has made this barrier beach fragile. Aside from wave action, human-induced factors were prominent in the catchment area, such as sand mining and artificial breaching of the barrier, accounting for the temporal changes in its physical characteristics. The paper recommends that the Cape Coast Metropolitan Assembly should play a critical role in protecting and maintaining the feature by regulating threatening human activities carried out on it.

Wetlands or Wastelands: A Water Resource in Crises. Assessing the Levels of Pollution and Degradation in the Fosu Lagoon in Ghana

Coastal lagoons and water resources provide numerous services to communities which are situated within their catchment area. These services ranges from food production to cultural heritage. This has made demand for them to increase thereby putting pressure on the resources. However, within the last few decades most lagoons have been turn into wastelands instead of servicing as a wetlands. Most of these lagoons have degradation by for settlement and polluted by industrial and domestic waste. One of such lagoon in Ghana which is under threat from human activities is the Fosu lagoon. This study therefore investigate the levels of degradation and pollution of the Fosu lagoon and how such incident could affect the livelihood of people who depend on the lagoon. The study employed questionnaire in the data collection process in four communities using a sample size of 40. Some respondents were also selected for the in-depth interview. The interview comprises fishermen, EPA etc. The data was analyzed using SPSS for the quantitative data and content analysis for the qualitative data. Result were generated in a form of frequency tables and charts. From the result obtained, it was observed that the lagoon has witnessed a decline in size and vegetative cover. This is attributed to mostly anthropogenic activities. As a result, it has affected the services provided by the lagoon which has led to loss of biodiversity as well as loss of livelihood. It is recommended that measures should be put in place to stop all forms of activities within the lagoon catchment area in order to restore the ecological integrity of the lagoon.

Mapping Seasonal Variation in the Distribution and Concentration of Heavy Metals Using Water Quality Index and Geographic Information System Based Applications

Incessant monitoring of water is essential in terms of heavy metals and toxic substances as it provides detailed information on aquatic resources. Majority of lagoons receive freshwater from their catchment areas containing industrial and domestic waste. The paper analysed seasonal variations in the distribution and concentrations of Lead (Pb), Copper (Cu), Cadmium (Cd),and Manganese (Mn) in the Fosu lagoon in Ghana to ascertain the quality of the lagoon. Water was sampled from eighteen (18) different points on the lagoon and was analysed at the Water Research Institute (WRI) of the Center for Scientific and Industrial Research (CSIR) using Atomic Absorption Spectrometry (AAS) and the results were interpolated using kriging.The results obtained were compared with the World Health Organisation water quality index. Statistical analysis of heavy metal concentrations using Pearson’s two-tailed significance correlation showed positive correlations for both seasons; between Pb and Cu (0.297; sig. = 0.232, and 0.196; sig.= 0.436), and Cd and Mn (0.119; sig. = 0.643 and 0.191; sig. = 0.447) for the wet and dry seasons respectively. A paired sample t-test on concentrations also showed statistical differences between wet and dry seasons’concentrations for Pb (t = 1.324; sig. = 0.203), Cu (t = 2.759; sig. = 0.013),and Cd (t = 3.056; sig. = 0.007), and Mn (t = -4.014; sig. = 0.001). Pb and Cd showed higher concentrations above the World Health Organisation's permissible limits. Heavy metal concentrations of water samples analysed varied widely in terms of seasons and sampling points.

The Tale of a Disappearing Lagoon: A Habitat Mapping and Ecological Assessment of Fosu Lagoon, Ghana

Coastal regions of Ghana are primarily engaged in sea and lagoon fishing. Like many lagoons in Ghana, Fosu lagoon is a major source of livelihood for its surrounding communities. However, the lagoon and its associated marsh vegetation is under serious threat from human-induced interference. Due to this, the lagoon is considered as one of the most polluted lagoons in Ghana. Also, studies reveal that a major conservation challenge is the lack of inventory for the lagoon’s associated vegetation. Hence, the research was to map and assess the lagoon’s habitat and identify threats to the lagoon. In achieving the research objectives, remote sensing and GIS technique were used to effectively map the lagoon and the catchment area. The result indicated that the Fosu lagoon is characterized by a massive decline in lagoon size and the vegetation cover. Thus, the standing water has declined by 50.2 acres from 1970 to 2017 to physical development and weeds. Also, it was evident in the result that the lagoon’s vegetation is now fragmented into six various vegetation types and the weeds in the lagoon make approximately one-third of the lagoon’s vegetation cover. Also, adding to the threat of the lagoon were high levels of plastic waste and metal pollution. Hence, if current trend continues, the possibility of further degradation is very high. The main impact of this research was to provide evidence to the gradual disappearance of the Fosu lagoon.

The Impact of Anthropogenic Activities on the Fosu Lagoon in the Central District of Cape Coast: Integrated Assessment of Heavy Metal Contamination

The Impact of Anthropogenic Activities on the Fosu Lagoon in the Central District of Cape Coast: Integrated Assessment of Heavy Metal Contamination

Concentrations and Health Risk Assessments of Heavy Metals in Fish from the Fosu Lagoon

Concentrations of Cu, Pb, Cr, Cd, Mn, Ni, Fe and Zn were determined in the muscle samples of Sarotherodon melanotheron from the Fosu Lagoon in Cape Coast using atomic absorption spectrophotometer. The results showed that, metal concentration in the fish muscle was in the order Mn > Zn > Fe > Pb > Ni > Cd > Cu > Cr. Mean concentrations of Pb and Cd in the fish exceeded the maximum tolerable limit set by the European Union. Although the mean concentrations of some metals exceeded this limit, their estimated daily intakes were below their oral reference dose recommended by the international regulatory bodies. Health risk assessment of consumers from the intake of metal contaminated in the muscle of S. melanotheron from the lagoon was evaluated by using Health Risk Index (HRI) calculations. In this study, the total HRI through consumption of fish calculated by adding the individual HRIs was less than 1, indicating that there is no significant potential health risk associated with the consumption of fish from the Fosu Lagoon.

Characterization of macro-benthic fauna for ecological health status of the Fosu and Benya lagoons in coastal Ghana

This study conducted a comparative analysis of benthic macroinvertebrate communities in the Fosu and Benya lagoons in Ghana, based on the anthropogenic effect on the two lagoons. Salinity, oxygen, temperature, conductivity, turbidity and pH were measured, invertebrate richness and species densities were determined. The AZTI Marine Biotic Index (AMBI) and multivariate statistics were used to determine the different responses of fauna to pollution. The fauna were categorized into five ecological groups based on the degree of tolerance of the different species to pollution: disturbance-sensitive species; disturbance-indifferent species, disturbance-tolerant species, second-order opportunistic species; and first-order opportunistic species. The Fosu Lagoon supported more pollution tolerant species, whereas the Benya Lagoon had more species that were sensitive to organic enrichment under relatively unpolluted conditions. Chironomus sp., which is adapted to virtually anoxic conditions, was the most abundant in the Fosu Lagoon whereas Nemertea sp. was the most abundant in the Benya Lagoon. The numerical and relative abundance (%) of all 7 taxa in the Fosu Lagoon was 1,359 and 92.35%, respectively. The numerical and relative abundance (%) of all 34 taxa in the Benya Lagoon was 2,459 and 87.52%, respectively. Expectedly, the level of dissolved oxygen in the less saline Fosu Lagoon was higher than that in the more saline Benya Lagoon. The reduced photoperiod and photosynthetic activities of aquatic plants might account for this trend. There is a need to implement comprehensive monitoring and management initiatives for sustaining the ecological health of coastal lagoons in Ghana in order to support the many people that depend upon these ecosystems for their livelihood.

Ecological Health Status of the Fosu Lagoon, Southern Ghana II: Environmental and Human Health Risk Assessment

This study set out to assess the levels, distribution and human health risk of Pb, As, Cd, Mn and polycyclic aromatic hydrocarbons (PAHs) in sediments from the Fosu Lagoon in Ghana. This was coupled with environmental fate modeling to investigate biodegradation behaviour of PAHs in sediment. Generally, the order of heavy metal enrichment for the sampling locations was Mn>Cd>Pb>As respectively. Only Mn showed significant enrichment at all sites. The observed PAH contamination demonstrated potential anthropogenic impact. The phenanthrene-anthracene ratio was less than 10 indicating that the PAHs originate from combustion. Benzo[b]fluoranthrene is the only carcinogenic PAH that was detected in the study. Regarding heavy metals in children, the total Hazard Index (HI) for ingestion and dermal route was 3.4×10-2 and 8.2×10-3 respectively for Central Tendency Exposure (CTE) whereas it was 2.1×10-1 and 1.0×10-1 for the Reasonable Maximum Exposure (RME) scenario. In adults, the total HI was 1.0×10-3 and 1.2×10-3, for ingestion and dermal routes respectively under the CTE scenario. For RME scenario, ingestion and dermal exposure had risk values of 2.2×10-2 and 3.1×10-2, respectively. Regarding PAHs, the total carcinogenic risk (RME) for children and adults were estimated as 1.02×10-5 and 8.38×10-6 respectively. The carcinogenic risk derived from the ingestion and dermal absorption of metals exceeded the generally acceptable risk level of 10-6 for individual chemicals, being slightly above 10-4. That risk level, basically due to the ingestion of As and Mn through sediments suggests potential harm to human health. The concentrations of PAHs in sediments did not present signii¬cant non-carcinogenic and carcinogenic risk for the local population. The fate modelling however, suggests that naphthalene, anthracene, benzo[b]fluoranthene, pyrene, fluorene and phenanthrene tend to sorb onto soil or sediment in the environment and biologically ‘‘do not degrade fast’’. This implies the need to implement long term monitoring of these compounds in order to sustain this fragile ecosystem.

Ecological Health Status of the Fosu Lagoon, Southern Ghana I: Biotic Assessment

Ecological Health Status of the Fosu Lagoon, Southern Ghana I: Biotic Assessment

<b>Assessment of heavy metals pollution of sediments from Fosu lagoon in Ghana</b>

The distribution of some heavy metals, namely Cu, Pb, Zn, and Fe in sediments of Fosu lagoon of Cape Coast, Ghana was studied in the early summer (November) of 2009. The levels of the selected trace metals were determined using atomic absorption spectrophotometry. The overall mean ± RSD % of Cu, Pb, Zn, and Fe were, respectively 26.4 ± 51.0, 28.1 ± 101.0, 20.90 ± 41.90 and 1.15 × 10 3 ± 2.02 mg/kg. Fe recorded the highest concentration levels, the distribution of which followed the sequence Fe > Pb > Cu > Zn. Statistical analyses also showed different mean levels of trace metals at the five sites. The heavy metal burdens in the sediments revealed significant variations in the distribution of the metals, with Pb showing the greatest variation and Fe the least. Enrichment level of Fe was minimal; Cu and Zn were significantly enriched and Pb showed very high to extremely high enrichment. The average geoaccumulation values and pollution load index calculated for the five studied sites indicated that the lagoon is practically unpolluted with Fe, Cu and Zn, but moderately polluted with Pb. KEY WORDS : Fosu lagoon, Heavy metal, Enrichment, Pollution Bull. Chem. Soc. Ethiop. 2011 , 25(2), 191-196.

Statistical Evaluation of Environmental Contamination, Distribution and Source Assessment of Heavy Metals (Aluminum, Arsenic, Cadmium, and Mercury) in Some Lagoons and an Estuary Along the Coastal Belt of Ghana

An environmental pollution investigation was carried out to determine the concentrations of aluminum (Al), arsenic (As), cadmium (Cd), and mercury (Hg) (heavy metals) in the surface water and river water bed sediments of lagoons and estuaries along the coastal belt of Ghana. The study assessed the environmental pollution situation and evaluated their sources and distribution of these metals. The total concentrations of Al, As, Cd, and Hg were determined by the neutron activation analysis technique. Water and sediment samples were collected from the Benya, Fosu, and Narkwa lagoons in the Central Region and from the Pra estuary in the western part of Ghana. Some indices, such as contamination factor, pollution-load index, contamination degree, and geoaccumulation index, were used to assess eco-environmental quality of the sampling sites. The analysis indicated that the Fosu lagoon was fairly polluted with Cd. The investigation indicated a highly localized distribution pattern closely associated with the two pollution sources (garbage/solid waste dumps and industrial activities) along the coastal belt. The resulting environmental deterioration required a concerted evaluative effort by all stakeholders.

Research Article: Ecosystem Restoration: Evaluating Local Knowledge and Management Systems of Fishermen in Fosu Lagoon, Ghana

This article evaluates fishermen's knowledge about the value of mangrove to fish stock and discusses possible management practices to help restore fish stock within the Fosu Lagoon, Ghana. The lago...

Participation and Sustainable Management of Coastal Lagoon Ecosystems: The Case of the Fosu Lagoon in Ghana

Participation as a tool has been applied as a social learning process and communication platform to create awareness among stakeholders in the context of resource utilisation. The application of participatory processes to aquatic ecosystem management is attracting a growing body of literature. However, the application of participation as a tool for sustainable management of coastal lagoon ecosystems is recent. This paper examines the context and the extent of participation of stakeholders in the management of the Fosu lagoon in Ghana. Six hundred individuals from twenty seven stakeholder groups were randomly selected for study. Both closed and open-ended questions were used in face-to-face interviews with stakeholders. The findings indicate that the stakeholder groups were not involved in decision-making regarding the conservation of the lagoon irrespective of their expertise in planning and/or their interest in lagoon resource utilisation. This situation has created apathy among some of the stakeholders who feel neglected in the decision-making process. There is scope for broadening the base of interest groups in decision-making processes regarding the lagoon and improving stakeholder participation in the management of the lagoon to ensure the sustainability of the management process.

<b>PESTICIDE RESIDUES IN THE WATER AND FISH (LAGOON TILAPIA) SAMPLES FROM LAGOONS IN GHANA</b>

This study was to ascertain the presence and subsequent amount of four organochlorine pesticides: dichlorodiphenyl dichloroethylene (2,4'-DDE), 4,4'-dichlorodiphenyldichloroethane (4,4'-DDD), p,p'-dichloro- diphenyltrichloroethane [p,p'-DDT (r) (i) (f)] and Propiconazol (f); and four organophosphorous pesticides: Fenitrothion (i), Chlorpyrifos (i), Dichlorvos (a) (i) and Diazinon (a) (i) in Chemu lagoon (Tema), Korle lagoon (Accra), Fosu lagoon (Cape Coast) and the Etsii lagoon (Abandzi). Liquid-liquid and liquid-solid extraction technique was employed to extract pesticide residues in water and fish samples, respectively, using 1:1 (v/v) ethyl acetate/dichloromethane mixture before being analyzed by gas chromatography. The highest level of pesticide contaminations was recorded in the Chemu lagoon as compared to the Korle lagoon and Fosu lagoon, with the Etsii lagoon showing the least contamination. The total average pesticide residues in water samples from the four lagoons: Chemu, Korle, Fosu and Etsii are 2.6384 mg/L, 0.4992 mg/L, 0.3045 mg/L and 1.3629 mg/L, respectively. The total average pesticide residues obtained in fish samples (Sarotherodon melaanothern) from the Fosu and Etsii lagoons are 0.0155 mg/kg and 0.0088 mg/kg, respectively. This shows some level of exposure of pesticide which would be harmful to human. KEY WORDS: Oraganochlorine, Organophosphorous, 2,4'-DDE, 4,4'-DDD, p,p'-DDT (r) (i) (f), Propiconazol (f), Fenitrothion (i), Chlorpyrifos (i), Dichlorvos (a) (i), Diazinon (a) (i), Chemu lagoon, Sarotherodon melaanothern Bull. Chem. Soc. Ethiop. 2009, 23(1), 19-27.

Assessment of dry season surface, ground, and treated water quality in the Cape Coast municipality of Ghana

This aim of this monitoring was to assess water quality in a dry season for the Cape Coast municipality in Ghana, which has been experiencing chronic water shortages. Fifteen different sampling stations--four surface, five ground, and six tap water samples--were analyzed for physicochemical and microbiological parameters during January to April 2005. Levels or trends in water quality that may be deleterious to sensitive water uses, including drinking, irrigation, and livestock watering have been noted with reference to well-established guidelines. Exceedances to some health-based drinking water guidelines included positive coliform for various water samples; pH for all groundwater samples (pH 5.9+/-0.3); conductivity for 50% groundwater; color for about a third of groundwater and tap water; Mn for 44% tap water, 67% groundwater, and 50% surface water samples. The World Health Organization laundry staining Fe guideline of 0.3 mg/l was exceeded by 75% of surface water, 44% tap water, and 53% groundwater samples. The corresponding Mn guideline of 0.1 mg/l was exceeded by all the water samples. Respectively, all surface water samples and also 75% of the surface water exceeded some known Cu and Zn guideline for the protection of aquatic life. Compared to some historic data for Fosu Lagoon, the current study shows a lowering of approximately 1 pH unit, increase of approximately 65% NH3, one to two orders of magnitude increase in PO4(3-), and more than two orders of magnitude increase in NO3-. In several instances, tap water samples collected at the consumers' end of the distribution system did not reflect on the true quality of the treated water. Mn, SO4(2-), PO4(3-), Cu, and Zn were among the chemical contaminations observed to occur in the distribution system.

Characterization and Source Assessment of Heavy Metals and Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments of the Fosu Lagoon, Ghana

The first results ever obtained on polycyclic aromatic hydrocarbon (PAHs) concentrations in the Fosu lagoon surface sediments are presented together with corresponding heavy metal (Fe, Mn, Cd, Zn and Ni) concentrations. Samples collected on a monthly basis from November 2003–April 2004 (Heavy metals) and December 2003–January 2004 (PAHs) at 8 locations, representing different anthropogenic sources of contamination to the lagoon, were analyzed. Concentrations of Cd and Ni in the lagoon sediment suggest greater contamination to the lagoon from industrial activities in the vicinity of the lagoon; 50% of the sediment samples exceeded some established sediment Cd guidelines for the protection of aquatic lives. Then, 15 PAHs were detected among the sediments from the different locations and the compositional pattern in decreasing order was 3-ring > 5-ring > 4-ring > 6-ring > 2-ring PAH compounds. Σ PAH concentrations in the sediment samples ranged from 254 to 558 mg/kg, with a mean of 359.4 mg/kg. Two distinct areas were identified to be a major source of anthropogenic load of both heavy metals and PAH; the mechanical shop in the northeastern sector of the lagoon is the main location for the input of Cd and it's associated PAH compounds (e.g., acenapthylene, acenaphthene, naphthalene and benzo[a]fluoranthene) and to a lesser extent Ni. Both combustion and petroleum sources may account for PAH loads from this area. The residential area in the northern sector is responsible for high loads of Mn and its associated PAH compounds (e.g., phenanthrene, benzo[a]pyrene and anthracene). These chemicals seem to enter the lagoon mainly by the combustion of especially wood or coal.

Assessment of the fishery of a stunted population of the cichlid,Sarotherodon melanotheron(Rüppel), in a “closed” lagoon in Ghana

Summary This aper examines the status of the tilapia fishery in Fosu Lagoon at Cape Coast, inthe Central Region of GLana (5°07’ N,1°6’ W). The blackchin tilaia, Sarotherodon melanotheron (Ruppel), constitutes about 90 % by weight of the total fish catch, and the annual yield of 452—664 kg/ha is apreciably higher than those reported for other tropical lagoons. Variations in the CPUE (0·30—0·96 kg/man-h) were related to fluctuations in the water level of the lagoon. Using the ELEFAN method, estimates of the growth and mortality parameters, based on length-frequency data were: Loo = 16·1 cm TL, K = 0·82/ yr, Z = 4·95/yr, M = 1·90/yr and F = 3·05/yr. The growth estimates and the maturity-length ratio suggest that the population is stunted. The mean length at first capture(Lcso) was estimated to be 6·2 cm TL. Although the present rate of exploitation (E= 0·62) appears high, an analysis of the relative yield-er-recruit (Y/R) and highrecruitment shows that this exploitation rate can be maintained by the Egoon population. Recruitment occurs throughout the year with two peaks, and this probably ensures the sustenance of the high yield.