Department of Marine and Fisheries Sciences

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    The charcoal footprint of greater Accra on the Afram Plains: Urban energy consumption and forest degradation in Ghana
    (Trees, Forests and People, 2024) Arko, T.; Mensah, A.; Obani, P.; Adomako, J.; Denton, F.
    Rapid urbanisation in sub-Saharan Africa is leading to increased energy consumption and a growing reliance on charcoal as a fuel source, with significant environmental implications. This study examines the impact of charcoal consumption in Greater Accra, Ghana, on the Afram Plains ecosystem. Employing a mixed-methods approach, including geographical analysis, quantitative data collection, and sustainability assessment, we evaluate the charcoal footprint of Greater Accra. Our findings reveal that charcoal remains the dominant cooking fuel in Greater Accra despite increased access to electricity, resulting in an estimated loss of 354,479 trees annually in the Afram Plains. This demand creates an ecological deficit of 18,850 hectares/yr, significantly exceeding the ecosystem’s regenerative capacity. We observe complex dynamics between urban energy needs and rural resource sustainability, highlighting socio-economic factors driving persistent charcoal use. The study proposes a conceptual framework integrating urban demand, rural supply, ecological impact, and natural regeneration. Our research contributes to urban sustainability literature, offering insights for policymakers to develop more sustainable energy strategies, including quota systems for harvesting, promoting alternative cooking fuels, community-based forest management, and improved charcoal production technologies. This case study provides valuable lessons for other rapidly urbanizing regions facing similar sustainability challenges in sub-Saharan Africa.
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    Seasonal Variability of Sea Surface Salinity in the NW Gulf of Guinea from SMAP Satellite
    (Remote Sensing in Earth Systems Sciences, 2022) Nyadjro, E.S.; Foli, B.A.K.; Agyekum, K.A.; et al.
    The advent of satellite-derived sea surface salinity (SSS) measurements has boosted scientific study in less-sampled ocean regions such as the northwestern Gulf of Guinea (NWGoG). In this study, we examine the seasonal variability of SSS in the NWGoG from the Soil Moisture Active Passive (SMAP) satellite and show that it is well-suited for such regional studies as it is able to reproduce the observed SSS features in the study region. SMAP SSS bias, relative to in-situ data comparisons reflects the differences between skin layer measurements and bulk-surface measurements that have been reported by previous studies. The study results reveal three broad anomalous SSS features: a basin-wide salinification during boreal summer, a basin-wide freshening during winter and a meridionally-oriented frontal system during other seasons. A salt budget estimation suggests that seasonal SSS variability is dominated by changes in freshwater flux, zonal circulation and upwelling. Freshwater flux, primarily driven by the seasonally varying Intertropical Convergence Zone is a dominant contributor to salt budget in all seasons except during fall. Regionally, SSS is most variable off southwestern Nigeria and controlled primarily by westward extensions of the Niger River. Anomalous salty SSS off the coasts of Cote d’Ivoire and Ghana, especially during the summer, is driven mainly by coastal upwelling and horizontal advection.
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    A record of change in oyster environment through high-resolution geochemical analysis of Late-Holocene sediments from Coastal Ghana
    (The Holocen, 2024) Mahu,, E.; Leng, M.J.; Andrews,L.; Englong,A.; Marchant, R.
    The near-coast environments where oysters occur are among the most impacted by humans globally, especially during the Late-Holocene. Yet, in West Africa, there is no documented historical record of change in these environments. We provide insight into the changing geochemical conditions of two oyster environments through high-resolution analysis of total organic carbon (C), total nitrogen (N), carbon and nitrogen isotope ratios (δ13C, δ15N), and trace elements, in two cores retrieved from the Densu estuary and the Anyanui (Keta) Creek in Ghana. Drastic shifts in sedimentation rate occurred in the Keta and Densu cores around 1996 CE and 960 CE respectively. At these times, comparatively, low levels of C and N were found in the Densu core. Increasing C and N levels and decreasing δ13C upcore aligned with the observed shift in sedimentation rate in the Keta core. The C/N ratios in the Keta core suggest allochthonous organic matter (OM) dominance in the creek. The Densu core showed periodic changes in C/N ratios from very high values (>20) between 1918 BCE and 1321 BCE, to values between 20 and 11 between 1321 BCE and 1977 CE and below 10 from the late 1970s CE to the present day, suggesting a varying degree of transformation in the catchment basin. Extremely high Sulfur (S) and moderate to significant Iron (Fe) increases suggest reducing conditions in the Keta sediments. Moderate Calcium (Ca), Zinc (Zn), and Strontium (Sr) concentrations in the upper part of the Densu core suggest a stronger influence of marine processes in the Densu in recent times. The findings reflect the impacts of catchment basin modification on the health of the two coastal environments, likely to impact the growth, productivity, and sustainability of the fishery of the West African mangrove Oyster.
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    Impact of the citizen science project Collect on ocean literacy and well-being within a north/west African and south-east Asian context
    (Frontiers in Psychology, 2023) Severin, M.I.; Mahu, E.; Akpetou, L.K.; et al.
    Plastic pollution is both a societal and environmental problem and citizen science has proven to be a useful tool to engage both the public and professionals in addressing it. However, knowledge on the educational and behavioral impacts of citizen science projects focusing on marine litter remains limited. Our preregistered study investigates the impact of the citizen science project Citizen Observation of Local Litter in coastal ECosysTems (COLLECT) on the participants’ ocean literacy, pro-environmental intentions and attitudes, well-being, and nature connectedness, using a pretest-posttest design. A total of 410 secondary school students from seven countries in Africa (Benin, Cabo Verde, Côte d’Ivoire, Ghana, Morocco, Nigeria, and Asia (Malaysia) were trained to sample plastics on sandy beaches and to analyze their collection in the classroom. Non-parametric statistical tests (n = 239 matched participants) demonstrate that the COLLECT project positively impacted ocean literacy (i.e., awareness and knowledge of marine litter, self-reported litter-reducing behaviors, attitudes towards beach litter removal). The COLLECT project also led to higher pro-environmental behavioral intentions for students in Benin and Ghana (implying a positive spillover effect) and higher well-being and nature connectedness for students in Benin. Results are interpreted in consideration of a high baseline in awareness and attitudes towards marine litter, a low internal consistency of pro-environmental attitudes, the cultural context of the participating countries, and the unique settings of the project’s implementation. Our study highlights the benefits and challenges of understanding how citizen science impacts perceptions and behaviors towards marine litter in youth from the respective regions.
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    A WAVEWATCH III® model approach to investigating ocean wave source terms for West Africa: Non-linear wave-wave interaction source terms
    (Applied Ocean Research, 2022) Foli, B.A.K.; Ansong, J.K.; Addo, K.A.; Wiafe, G.
    Ocean wave forecasting for West Africa has mostly relied on global parameterization schemes and data outputs. Investigating non-linear ocean wave-wave interaction source terms (Snl) for the region that forms part of the wave model parameterization schemes, is a contribution of this study towards developing a regional wave modelling scheme for West Africa. The study evaluates five non-linear source-term configurations with the WAVEWATCH III® (WW3) numerical ocean wave model version 5.16; (i) No source term applied (NL0); (ii) Discrete Interaction Approximation (DIA): NL1, (iii) Exact Interaction Approximation: NL2, (iv) Generalized Multiple DIA (NL3) and (v) Two-Scale Approximation (NL4) in order to determine best-performing Snl for projecting significant wave heights and directions for the region. The wave simulations were run on three separate grids comprising a low-resolution West Africa grid (latitudes 10° S–30° N; longitudes 35° W–15° E), high-resolution south-eastern (latitudes 2o S – 8o N; longitudes 10o W – 10o E) and north-western (latitudes 10o N) – 25o N; longitudes 30o W – 10o W) sub-grids. Simulations for the entire West Africa grid produced higher accuracy for the wave parameters compared to the higher-resolution sub-grids. NL0 best estimates are significant wave height, whereas NL3 best estimates wave directions for the West Africa grid. For combined stations of the south-eastern sub-grid, while NL1 best estimates wave heights, NL3 best estimates the wave directions with possible alternation with NL1 due to insignificant differences. Similarly, for the north-western sub-grid, while NL1 best estimates significant wave heights; NL0 best estimates wave directions with similar ability to alternate with NL2 in projecting wave directions. Generally, insignificant differences exist between the source terms in projecting wave directions, especially for the north-western sub-region, implying that any of the source terms may be used in projecting wave directions without significantly compromising on accuracy. Thus, NL1, which best estimates significant wave heights for both the south-eastern and north-western sub-regions can also be used in estimating the wave directions. Similarly, NL0 would be appropriate for the entire West African region
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    Resilient Lagoons? Climate Change, Sustainability And Adaptation
    (Geography, 2022) Davies-Vollum, K.S.; Agyekumhene, A.; Addo, K.A.; et al.
    Lagoons are found at low-lying coastlines around the globe (Figure 1) and their associated wetlands are important, dynamic environments. Ensuring the sustainability of the world’s lagoons is vital for communities, ecosystems and economies. Lagoons support highly productive ecosystems and provide critical ecosystem services, societal benefits and myriad fundamental and valuable resources that are vital for the wellbeing and livelihoods of coastal communities. Yet, the sustainability of lagoons and the communities that rely on them are under increasing pressure from a complex set of interconnected issues, including climate change, sea-level rise, pollution, poor waste management, population growth and policy approaches that favour top-down governance to the exclusion of local knowledges and priorities (Convention on Wetlands, 2021). This article summarises the latest research on lagoons using the examples of Muni Lagoon in Ghana and Lagos Lagoon in Nigeria (Figure 1). It also draws from the interdisciplinary dialogues emerging through the Global Challenges Research Fund (GCRF)-funded Resilient Lagoon Network (see website), which seeks to challenge top-down management approaches and instead prioritise participatory approaches that value local knowledges and in which coastal communities are central to resilient lagoon governance.
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    Enhancing Satellite Oceanography-Driven Research in West Africa: a Case Study of Capacity Development in an Underserved Region
    (Remote Sensing in Earth Systems Sciences, 2021) Nyadjro, E.S.; Mahu, E.; Addo, K.A.; et al.
    Marine business and resources play a major role in the economics and way of life in coastal West African countries. Such countries see great profitability from their marine resources while also facing challenges that come with a bordering sea. Despite Due to this fact, there has been limited research into the optimal way for West African Coastal States to coexist with and sustainably use their marine resources, a research deficit that is mainly due to a lack of infrastructure for in-situ work, lack of capacity development, and comprehensive datasets to undertake oceanographic research. The Coastal Ocean Environment Summer School in Ghana (COESSING; www.coessing.org) was developed to help meet some of these challenges. Each summer since 2015, ocean scientists (e.g., biologists, chemists, physicists, hydrologists) from the USA and Europe have collaborated with West African colleagues to lead a week-long intensive summer school in Accra, Ghana, alternating in location between the Regional Maritime University and the University of Ghana. The school receives in excess of 100 participants drawn from universities, government agencies, and private sector organizations, mainly from Ghana and neighboring Liberia, Nigeria, Togo, and Benin, among others. The format of the school includes morning lectures, afternoon field trips, hands-on laboratory exercises and one-on-one coaching of students. Important to the COESSING program is the satellite oceanography component, which introduces participants to the extensive and often free, remotely sensed oceanographic datasets. Participants develop skills that allow them to access, process, and analyze these datasets in order to better understand regional oceanographic phenomena, such as upwelling, pollution, habitat characterization, sea level rise, and coastal erosion. Following school, facilitators keep in touch with program participants, helping them acquire and analyze data for their studies, dissertations, and often graduate school applications, etc. In summary, schools such as COESSING are critical not only for science in the region but for the global ocean community as such training develops eager, bright minds while leading to improved regional observation and modeling strategies in severely under-sampled seas. Here, we describe a unique case in which satellite oceanography has led to such outcomes for countries bordering the Gulf of Guinea, West Africa
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    Correction: Perceptions of commercialisation and value‑addition of non‑timber forest products in forest adjacent communities in Ghana
    (Discover Sustainability, 2024) Asamoah, O.; Boateng, C.M.; Appiah, M.; et al.
    This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source. provide a link to the Creative Commons license and indicate if changes were made. The images or other third-party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0
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    Assessment of Exploited Population Dynamics of African Butter Catfish (Schilbe mystus) in Stratum VII of Lake Volta, Ghana
    (Egyptian Journal of Aquatic Biology & Fisheries, 2023) Asiedu, B.; Amponsah, S.K.K.; Ofori-Danson, P.K.; Nunoo, F.K.E
    The current study aimed to assess the population status of Schilbe mystus in stratum VII of Volta Lake, Ghana, based on length-frequency data collected throughout 2021. Individual fish samples, ranging from 5.5 to 22.0cm with a mean length of 11.5± 0.17cm, were analyzed using FiSAT II. The study revealed a mean condition factor of 0.36, indicating the fish's overall health. The growth pattern, estimated at 3.1 suggested positive algometric growth. The growth rate (K) was determined as 0.25 per year. Length at infinity (L∞), length at first capture (Lc50), and length at first maturity (Lm50) were calculated as 24.7, 10.27, and 16.47cm, respectively. The growth performance index was recorded at 2.58. The total mortality rate (Z) was calculated as 2.09 per year, with the natural mortality rate (M) at 0.78 per year and the fishing mortality rate (F) at 1.31 per year. The exploitation rate was 0.63, indicating overexploitation of S. mystus in Stratum VII. To sustain the stock size of the S. mystus fishery in Lake Volta, we recommend reducing fishing efforts, regular status assessments, and enforcement of fisheries regulations
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    Food and Feeding Habits of the Big-eye Grunt, Brachydeuterus auritus (Valenciennes, 1831) in the Coastal Waters off Tema, Ghana
    (West African Journal of Applied Ecology, 2023) Lamptey, A.M.; Kwansa-Bentum, B.; Gbogbo, F.; et al.
    Examination of 424 stomach contents of Big-eye Grunt and Brachydeuterus auritus from May and September December 2016 showed four major food groups. In decreasing order of abundance, these are: crustacea (64%), fish (35%), molluscs (0.4%), and insects (0.3%). Anchovies were the commonest prey types, with a frequency of occurrence of 53.6%, followed, among the crustaceans, by lobster larvae (34.5%) and shrimp larvae (5.3%). Crab zoe larvae and crab shell had very low frequencies (<1.0% each). Molluscs, represented by squid and juvenile cuttlefish, and insects, represented mainly by chironomid larvae, both had very low frequencies (<1.0). A low feeding intensity was recorded in October and November, a period coinciding with the highest number of fish with empty stomachs. Conversely, a greater feeding activity was recorded in May, September and December, a period coinciding with the highest number of fish with ¼, ½, ¾ and full stomachs. The proportion of crustaceans in stomach contents increased significantly with increasing size of B. auritus, while the proportion of fish significantly decreased with age. It is recommended that stomach content analysis of this fish species should be replicated to cover all seasons and other geographical areas.