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Population parameters for Red Pandora, Pagellus bellottii (Steindachner, 1882) from the eastern coastline of Ghana, using length-frequency data from June 2014 to January 2015 were assessed. A total of 440 samples of Pagellus bellottii... more
Population parameters for Red Pandora, Pagellus bellottii (Steindachner, 1882) from the eastern coastline of Ghana, using length-frequency data from June 2014 to January 2015 were assessed. A total of 440 samples of Pagellus bellottii were measured for standard length and analyzed with FiSAT II. The asymptotic length (L∞) and growth rate (K) were 19.43 cm and 0.42 per year. Theoretical age at birth (t0 ) and growth performance index (ϕ) were -0.44 per year and 2.20. The age at first maturity (tm50) and longevity (tmax) were 2.2 years and 7 years. The Bhattacharya’s method revealed three modal lengths groups: 9.3 cm, 12.1 cm, and 14.6 cm. Total mortality rate (Z), natural mortality rate (M) and fishing mortality rate (F) were 2.58 per year, 1.10 per year, and 1.48 per year. Exploitation rate (Ecurrent) and maximum exploitation rate (Emax) were estimated as 0.57 and 0.93 respectively. The recruitment pattern was continuous with two major recruitment pulses. VPA outcome showed that mid...
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Food security exists when all people meets their dietary needs and food preferences for an active and healthy life. The Volta delta for DECCMA covers about 3,301 sq km with total population of 863,810. Agriculture and fisheries are the... more
Food security exists when all people meets their dietary needs and food preferences for an active and healthy life. The Volta delta for DECCMA covers about 3,301 sq km with total population of 863,810. Agriculture and fisheries are the largest economic activities. Home to several fish species such as tilapia, mudfish, oysters, shrimps and others. Accra, Keta, Aflao and other cities are economic centres for fisheries products. The objective of this study is to model economically the impact of climate change on fisheries as input into IO table for prediction under different climate scenarios for 2030, 2060 and 2100 (WP4).
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This study investigated the prevalence rate, relative abundance and mean intensity of parasites infecting cultured Nile tilapia Oreochromis niloticus L. in three fish farms, Gbarnga, Warta and CARI in Bong County, Liberia. Organs from... more
This study investigated the prevalence rate, relative abundance and mean intensity of parasites infecting cultured Nile tilapia Oreochromis niloticus L. in three fish farms, Gbarnga, Warta and CARI in Bong County, Liberia. Organs from thirty fish samples were examined from September 2016 to February 2017, along with water quality parameters. Results showed the occurrence of seven parasites including protozoans, monogeneans, digeneans, cestodes, hirudineans, nematodes and crustaceans which were organ specific in terms of infection. The prevalence of the parasites varied seasonally, with the highest numbers occurring in November-January. The low prevalence rate, relative abundance and mean intensity of the parasites showed no threat to fish farmers in Liberia. All the water quality parameters were at desirable levels for the culture of the fish except nitrite, which was beyond the threshold for sustainable fish culture. It is therefore concluded that although parasitic infections ...
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Abstract This chapter looks at the impacts of hydropower development on fisheries resources using the Bui dam project as a typical case study. Specifically, the chapter focuses on the following areas: impacts of impoundments on riverine... more
Abstract This chapter looks at the impacts of hydropower development on fisheries resources using the Bui dam project as a typical case study. Specifically, the chapter focuses on the following areas: impacts of impoundments on riverine ecosystems, food security and fish consumption, fish diversity, fish and fishers’ migration. The increasing demand of energy for social and economic development of the world and in particular the Ghanaian economy has resulted in the creation of dams to generate electricity. Amidst poor planning, construction and monitoring of dams has adverse effects on fishers and fishing communities, evidence in the loss of many livelihoods. There is therefore the need to better manage dams to sustain livelihoods of fishing communities and fish stocks.
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Understanding environmental baseline parameters within Gulf of Guinea offshore areas— as relevant delineating conditions favourably ensuring the survival of marine life bounded within was examined against environmental baseline surveys... more
Understanding environmental baseline parameters within Gulf of Guinea offshore areas— as relevant delineating conditions favourably ensuring the survival of marine life bounded within was examined against environmental baseline surveys (EBS) conducted during the Environmental Impact Assessment (EIA) by licensed oil and gas operators of the region. The case of the EBS within Ghana’s western basin is mainly because offshore marine habitation over a decade has seen a rise in anthropogenic activities. Current concerns span pollution, over-exploitation of natural resources, air emissions, growing anthropogenic activity, and climate change. A series of samplings were taking at essential offshore and coastal facility locations to investigate baseline ocean environment; understand the nature of ecology and identify issues of vulnerabilities that could ensure destructive tendencies. The paper observes EBS conditions were consistent with findings of EIAs. The tropical nature of the region mea...
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The study was undertaken in three communities namely Adamrobe, Aburi and Pokrom-Nsaba, all located in the Akuapim South District of the Eastern Region. These communities depend on streams, wells, and springs for their drinking water... more
The study was undertaken in three communities namely Adamrobe, Aburi and Pokrom-Nsaba, all located in the Akuapim South District of the Eastern Region. These communities depend on streams, wells, and springs for their drinking water requirements. The objective of the study was to assess the trace metals quality of the drinking water sources used by the communities. Water samples from these sources (streams, wells, and springs) were analyzed over a period of twelve months for various water quality parameters including the following trace metals: lead (Pb), cadmium (Cd), zinc (Zn), & arsenic (As), following standard methods designed in APHA, AWWA, and WEF. The results of the study revealed that, most of the mean levels of trace metals registered from the water samples were below the World Health Organization (WHO) and Ghana Water Company Limited (GWCL) recommended critical limits for drinking water standards. The low level of trace metals recorded in the water samples was due to the a...
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The most reliable way of monitoring fisheries performance is by a standardized reporting of relevant data by well-trained observers. The Fisheries Enforcement Unit (FEU) of Ghana has trained about 200 observers for deployment on Ghanaian... more
The most reliable way of monitoring fisheries performance is by a standardized reporting of relevant data by well-trained observers. The Fisheries Enforcement Unit (FEU) of Ghana has trained about 200 observers for deployment on Ghanaian flagged trawlers to curb illegalities committed during fishing expeditions and also to collect data that cannot be taken when using the Vessel Monitoring System (VMS). These observers were deployed on 831 trips of industrial trawl vessels for fishing expeditions from July 2015 to March 2019. Total (100%) on-board observer coverage, however, started from March 2018 since January and February were declared as closed season. Using the catch data from March to December 2018, a sub-sample of 162 observer trips out of the 543 observer trips in 2018 was compared to catch data declared and landed by the trawler operators. Observers declared a total of 19,771.08 tonnes of fish against total tonnage of 16,468.21 declared by trawler operators indicating a diff...
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The ichthyofaunal diversity and limnology of Kpong and Oyun reservoirs located in Ghana and Nigeria respectively were studied with the main aim of gathering useful information to support the development, management and sustainable use of... more
The ichthyofaunal diversity and limnology of Kpong and Oyun reservoirs located in Ghana and Nigeria respectively were studied with the main aim of gathering useful information to support the development, management and sustainable use of their respective fisheries to enhance the socio-economic status of riparian communities. Experimental fishing with a battery of gill nets of various mesh sizes was used to sample for fishes monthly (September 2014 to August 2016) were individually identified, weighed and measured for standard and total lengths. Water samples were taken monthly and analyzed for physico-chemical parameters. Cichlidae and Mormyridae were the most abundant families in Kpong reservoir accounting for 77.7% and 8.7% respectively and Mochokidae was the least occurring with 2.0% while Oyun recorded Cichlidae, Claridae and Mormyridae as the most important families encountered with 45.99%, 25.41% and 12.2% respectively with Channidae (0.5%) the least occurring. In the Kpong Re...
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Population parameters (growth, mortality and exploitation rates) and the fishing regime of Scomber japonicus along the eastern coastline of Ghana were assessed using FiSAT II software for samples collected from August, 2014 to January... more
Population parameters (growth, mortality and exploitation rates) and the fishing regime of Scomber japonicus along the eastern coastline of Ghana were assessed using FiSAT II software for samples collected from August, 2014 to January 2015. The asymptotic growth (L∞) and growth rate (K) were 26.73 cm (standard length) and 1.30 per year respectively. The annual instantaneous rate of total mortality (Z), fishing mortality (F) and the natural mortality (M) were estimated at 5.02 per year, 2.92 per year and 2.10 per year respectively. The exploitation rate (Ecurrent) was 0.58. The maximum yield per recruit could be achieved at Emax = 0.72 and Lc = 0.49. Results from the study showed that the Scomber japonicus fishery is relatively heavily exploited with its fishing regime currently residing in the overfished domain, hence urgent management policies should be taken to ensure its sustainability for both future and present generation fish protein needs.
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A geographic information system (GIS)-modeling of fish production in the Stratum VII of the Volta Lake was undertaken with the objective of investigating temporal changes and modeling fish production into the future. Parameters used... more
A geographic information system (GIS)-modeling of fish production in the Stratum VII of the Volta Lake was undertaken with the objective of investigating temporal changes and modeling fish production into the future. Parameters used included number of canoes, number of fishers, and water level. Stratum VII of the Volta Lake is currently one of the areas with the highest fishing activities, the largest fish market at Yeji and relatively a research center. Nevertheless, the lake has faced many setbacks due to poor management and monitoring. In order to combat these challenges, this study was conducted to investigate the temporal changes and forecasting production of Stratum VII of the Volta Lake using Geographic Information System. Long term field data from 1970 to 1998 on fisheries were acquired and analyzed for modeling fish production from 1970 to 2060, using ArcGIS management tools and model builder. A hind cast was first performed to validate the model. The model, “CPUE model” pr...
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Results of a twelve-month assessment of the fisheries and aquaculture potential of small waterbodies (SWBs) in the West Gonja District of Northern Ghana are presented. The primary objectives of the project were to established whether the... more
Results of a twelve-month assessment of the fisheries and aquaculture potential of small waterbodies (SWBs) in the West Gonja District of Northern Ghana are presented. The primary objectives of the project were to established whether the fisheries within the reservoir basins in the West Gonja and Nanumba Districts (Northern Region) could be enhanced and aquaculture associated with the SWBs could be viable.
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Pre- and post-impoundment studies of physical and chemical parameters of water in the Bui dam area of the Black Volta were carried out from March 2011–December 2012. The physico chemical parameters monitored fell within the ranges... more
Pre- and post-impoundment studies of physical and chemical parameters of water in the Bui dam area of the Black Volta were carried out from March 2011–December 2012. The physico chemical parameters monitored fell within the ranges suitable for the sustenance of aquatic life in freshwater bodies with the exception of dissolved oxygen, nitrates, sulphates and phosphates. The physicochemical characteristics showed wide seasonal variations, while between sampling stations the differences were insignificant (p>0.05). Electrical conductivity, total dissolved solids, colour, dissolved oxygen, nitrates and sulphates differed significantly (p<0.05) in the pre-impoundment (March–May 2011), immediate post-impoundment (June December 2011) and late postimpoundment (January–December 2012) periods. Hence, reflecting the alterations in the river continuum due to impoundment. Nitrates, sulphates and phosphates were outside recommended ranges suitable for aquatic life. The reasons for these hi...
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Aquaculture is a preferred alternative to increasing global fish production than management of wild stocks. Its practice is, however, known to have ecological impacts if not managed well. The study was conducted to determine the potential... more
Aquaculture is a preferred alternative to increasing global fish production than management of wild stocks. Its practice is, however, known to have ecological impacts if not managed well. The study was conducted to determine the potential impact of cage culture of fish on food preference of wild fish. A case study was carried out in the Volta Lake at Kpeve-Tornu using Chrysichthys species which is one of the dominant species found in the Lake. Sampling was done for eight months from August 2013 to March 2014. An area of the lake with no fish farming activities was used as a control. The stomachs of 130 Chrysichthys specimens were analyzed. Importance of each food item was determined using frequency of occurrence method. The dominant food items identified were chironomid larvae and detritus; occurring in 27.3% and 36.4% respectively of the stomach contents at the cage culture site and 63.9% and 52.8% at the control site respectively. Plant parts also occurred in 36.4% of the stomachs at the cage culture site. Lampsilis species, a freshwater mussel, was found only in the stomachs at the control site and it occurred in 41.7% of them. Cage culture in the Volta Lake impacted on the food preference of Chrysichthys species by influencing the availability and abundance of food items. As promising as cage culture is in Ghana; in supplementing production from capture fisheries, it must be done on a scale that keeps its ecological impacts in the Volta Lake in control.
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Background: Ghana’s marine artisanal fisheries, particularly the small pelagic fisheries, are in a state of crisis. The decline in the number of small pelagic fish are attributable to overfishing, climate variability and unsustainable... more
Background: Ghana’s marine artisanal fisheries, particularly the small pelagic fisheries, are in a state of crisis. The decline in the number of small pelagic fish are attributable to overfishing, climate variability and unsustainable fishing methods. Similarly, in the wake of climate change, shellfishes (particularly oysters, scallops and mussels) are highly vulnerable. Methods: A total of 55 years’ worth of data from Ghana’s marine artisanal fisheries were studied in relation to climate indices. The primary objective was to develop a simple linear regression model for predicting shellfish catch in Ghana. Key informant interviews were employed in soliciting data on changes in climate along the coastline and trends in marine artisanal shell fish catch. Results: The predictor variable that significantly explained shellfish production was temperature. Hence, the model is a valuable tool to predict future trends in the shellfish catch in marine artisanal fisheries. Conclusions: Increa...
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Following the declining stocks of Sardinella aurita within the coastal waters of Ghana, this study aimed at examining some population parameters of Sardinella aurita as a guide for managing this important stock sustainably.... more
Following the declining stocks of Sardinella aurita within the coastal waters of Ghana, this study aimed at examining some population parameters of Sardinella aurita as a guide for managing this important stock sustainably. Length-frequency data of 717 samples were obtained from June, 2014 to January 2015 and measured for total length with the resultant data analyzed using FiSAT II. The asymptotic length (L∞) and growth rate (K) were 21.53 cm SL and 0.25yr-1 respectively. The theoretical age at birth (t0), longevity (tmax) and growth performance index (ϕ) were -0.74yr-1, 12 years and 1.849 respectively. Total mortality rate (Z), natural mortality rate (M) and fishing mortality rate (F) were 3.17, 0.76 and 2.41yr-1 respectively. The ages at first recruitment and first capture signaled future collapse of the stock, in the absence of proper management interventions. VPA outcome showed that mid- lengths of 11 cm and 12 cm SL experienced the highest harvesting rate with MSY estimated at ...
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Deltas are home to a large and growing proportion of the world's population, often living in conditions of extreme poverty. Deltaic ecosystems are ecologically significant as they support high biodiversity and a variety of fisheries,... more
Deltas are home to a large and growing proportion of the world's population, often living in conditions of extreme poverty. Deltaic ecosystems are ecologically significant as they support high biodiversity and a variety of fisheries, however these coastal environments are extremely vulnerable to climate change. The Ganges-Brahmaputra-Meghna (Bangladesh/India), the Mahanadi (India), and the Volta (Ghana) are among the most important and populous delta regions in the world and they are all considered at risk of food insecurity and climate change. The fisheries sector is vital for populations that live in the three deltas, as a source of animal protein (in Bangladesh and Ghana around 50-60% of animal protein is supplied by fish while in India this is about 12%) through subsistence fishing, as a source of employment and for the wider economy. The aquaculture sector shows a rapid growth in Bangladesh and India while in Ghana this is just starting to expand. The main exported species ...
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The fisheries of the Black Volta near the Bui dam in Ghana were studied during the pre-and post-impoundment periods between February 2011 and December 2012. The primary objective was to assess the ecological impact of the dam on the... more
The fisheries of the Black Volta near the Bui dam in Ghana were studied during the pre-and post-impoundment periods between February 2011 and December 2012. The primary objective was to assess the ecological impact of the dam on the fisheries. During the survey, a sampling unit was considered as a fishers' catch per canoe per day. A three-level stratified random sampling approach was adopted. The first stratum which was defined by four designated hydrological seasons in the study area was as follows: dry season (January to March); pre-wet season (April to June); wet season (July to September); and post-wet season (October to December). The second stratum was defined by the three impoundment periods: pre-impoundment (March to May 2011); immediate post-impoundment (June to December 2011); and late post-impoundment (January to December 2012). The third stratum, on the other hand which was defined to improve sampling for accuracy was: above the dam site or reservoir area with sampli...
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Areview of waterbirds was undertaken in two coastal Ramsar lagoons, namely the Keta and Muni Ramsar sites in Ghana, West Africa, from August 2010 to March 2012 to determine the status of diversity and abundance of key waterbired species... more
Areview of waterbirds was undertaken in two coastal Ramsar lagoons, namely the Keta and Muni Ramsar sites in Ghana, West Africa, from August 2010 to March 2012 to determine the status of diversity and abundance of key waterbired species that utilize the lagoons. A total of 20,217 of waterbirds belonging to 25 different species, 19 genera and 10 families were counted in the two lagoons. Maximum count of 19,757 contributing to 97.7% of the total counts was recorded in Keta Lagoon area while 460 contributing to 2.3% of the total count was recorded in the Muni Lagoon area. By comparison with the Save the Seashore Birds Project-Ghana (SSBP-G), which started in 1983 and ended in 1985, a total of 53,500 of waterbirds were counted in the Keta Lagoon, an indication of a 63.1% decline in waterbirds abundance. Atotal of 24 species was recorded in the Keta Lagoon and its surrounding floodplains (H"= 0.94, J"= 0.68 and d"= 2.32), whilst the Muni Lagoon recorded a lower number of s...
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Organochlorine (OC) pesticide residues (heptachlor, p,p'-DDT, p,p'-DDE, γ-HCH, δ-HCH, α-endosulfan, β-endosulfan and methoxychlor) and heavy metals (Cu, Mn, Cd and Hg) were analyzed in the blubber, liver and muscle tissues of two... more
Organochlorine (OC) pesticide residues (heptachlor, p,p'-DDT, p,p'-DDE, γ-HCH, δ-HCH, α-endosulfan, β-endosulfan and methoxychlor) and heavy metals (Cu, Mn, Cd and Hg) were analyzed in the blubber, liver and muscle tissues of two species of dolphins (Stenella clymene and Grampus griseus) from the coastal waters of Ghana. Concentrations of OC pesticide residues were measured using gas chromatograph-electron capture detector (GC-ECD) while concentrations of heavy metals were measured using instrumental neutron activation analysis (INAA). Concentrations of OC pesticide residues ranged from < 0.01 to 6.54 ngg-1 wet weight. Concentrations of OC pesticide residues increased with lipid content and were significantly higher (p < 0.05) in the blubber than the liver and muscle, indicating the lipophilic nature of the OC pesticides. The γ-HCH residue was most frequently detected at relatively higher concentrations than the other OC pesticide residues detected. Concentrations of h...
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Research Interests: Landscape Ecology, Earth Sciences, Environmental Science, Puerto Rico, Medicine, and 15 moreBiological Sciences, Land use and land cover, Phosphorus, Environmental Sciences, Spatial Heterogeneity, Land Cover, Land Use, Nitrogen, Data Collection, Secondary Forest, Ecosystem service, Human Activity, Dissolved Oxygen, Large Scale, and Land Cover Mapping
The population dynamics of the mochokid, Hemisynodontis membranaceus (Geoffroy St. Hilaire, 1809), a dominant fish species in purse seine or “winchnet” catches in Stratum VII of Lake Volta, were studied using length frequency data. Using... more
The population dynamics of the mochokid, Hemisynodontis membranaceus (Geoffroy St. Hilaire, 1809), a dominant fish species in purse seine or “winchnet” catches in Stratum VII of Lake Volta, were studied using length frequency data. Using the FAO-ICLARM Stock Assessment (FISAT) Software, the von Bertalanffy growth parameters, L¥, K and to were estimated for the fish as 44.0 cm Standard Length, 0.55 per year, and 0.26 year respectively. The natural mortality coefficient, M was found as 1.12 year-1; fishing mortality coefficient, F= 2.91 year-1; and the total mortality coefficient, Z found as 4.03 year-1. The exploitation rate, E = F/Z was thereby found as 0.72 indicating that the species is over-exploited requiring immediate management attention. At least 4 year groups or cohorts were found to occur on the fishing grounds which have a longevity of about 5 years. The average annual yield of H. membranaceus by winchboats (purse seine) is estimated as 4,000 tonnes. Information available from Thompson and Bell analysis suggest that a Maximum Sustainable Yield (MSY) of 4,800 tonnes per annum of H. membranaceus may be achieved when the present fishing effort of winchboats is reduced by about 20%. Any further increase in the effort is not expected to increase the average yield. JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 1 Number 2, January (1999) pp. 43-52