The University of Dar es Salaam (UDSM) is a public university in Dar es Salaam, Tanzania. It was established in 1961 as an affiliate college of the University of London. The university became an affiliate of the University of East Africa (UEA) in 1963, shortly after Tanzania gained its independence from the United Kingdom. In 1970, UEA split into three independent universities: Makerere University in Uganda, the University of Nairobi in Kenya, and the University of Dar es Salaam.
Fishing, especially within industrial sectors, is widely recognized as one of the most dangerous occupations in the world, as fishers are exposed to adverse physical and environmental risks. While legal frameworks in Nigeria provide occupational safety and labor protections for industrial fishers, inconsistencies in enforcement and compliance persist. Voluntary sustainability standards (VSS) have been promoted as market-based mechanisms to reduce risks, increase safety compliance, and improve working conditions. Despite their relevance, evidence of their impacts on industrial fisheries remains unclear. This study examines the effects of the Friend of the Sea (FOS) certification program on the occupational safety and working conditions of industrial fishers in Nigeria's Gulf of Guinea, Atlantic Ocean. A mixed methods approach was employed, integrating quantitative surveys with semi-structured interviews with key informant to facilitate triangulation among participants recruited from FOS-certified and Business as Usual (BAU) fishing companies. Bivariate analyses revealed that FOS-certified fishers were significantly more likely to have adequate safety equipment (98.0% vs. 74.8%), access to health personnel and emergency services (100% vs. 17.4%), and training opportunities (98.5% vs. 46.8%). Multivariate logistic regression confirmed these associations such that absence of safety equipment was associated with a 0.364 decrease in the probability of FOS certification; no injury history with a 0.291 increase; no exposure to unsafe conditions with a 0.400 increase; and lack of training access with a 0.535 decrease (all p < 0.001). These findings suggest that, despite statutory legal protections in Nigeria, participation of fishing companies in the FOS certification programme may enhance the implementation of safety standards and improve occupational health outcomes among industrial fishers.
Enhanced oil recovery (EOR) integrated with CO2 geological storage provides a promising pathway to meet energy demand while mitigating CO2 emissions. However, simultaneously maximizing oil recovery and ensuring long-term CO2 storage security remains a critical challenge. This study investigated the dual functionality of a novel amine-functionalized nanofluid (NF) prepared by grafting 3-aminopropyltriethoxysilane (KH550) and polyethyleneimine (PEI) onto silica nanoparticles for simultaneous EOR and CO2 sequestration. Core flooding experiments were conducted at 80 degrees C and 12.0 MPa to compare the performances of CO2-saturated nanofluid (NF) with conventional CO2-saturated low-salinity water (LSW), commonly referred to as carbonated water (CW). The experimental results demonstrated that LSW-soaked (water-wet) NF flooding achieved a final oil recovery of 82.79%, exceeding that of LSW-soaked (water-wet) CW flooding and unsoaked (oil-wet) NF flooding, highlighting the importance of wettability modification. More importantly, the nanofluid substantially enhanced CO2 immobilization. The soaked NF flood retained 57.64% of the injected CO2, compared with 38.89% for the soaked CW flooding and 49.65% for unsoaked NF flooding. Post-flooding analyses after a 7-day shut-in revealed pronounced geochemical alterations. SEM images showed extensive mineral corrosion and dissolution vugs in NF-treated cores, while CW-treated cores exhibited only mild surface pitting. The significant differences observed in the XRD patterns after NF flooding, along with the changes in the relative C/O elemental contents, further confirmed the mineralogical and surface-chemical alterations induced by the treatment. Overall, this study demonstrated the strong potential of CO2-saturated NF as dual-purpose agents for CO2-EOR while enhancing CO2 retention and promoting favorable geochemical conditions for long-term geological storage.
Heavy metal contamination is an increasing environmental and public health concern in Tanzania due to rapid urbanization, mining, industrialization, and intensified agriculture. This scoping review synthesizes 177 peer-reviewed studies published between 2000 and 2024 on heavy metals in environmental, food, cosmetic, medicinal, aquatic, and human matrices in Tanzania. The findings show a steady rise in research, with peak publications between 2015 and 2019. Atomic absorption spectroscopy was the most commonly employed analytical method, followed by ICP-based techniques, XRF, and other spectroscopic approaches. The most studied heavy metals are Pb, Cd, Cu, Zn, Cr, Hg, and As, while Co, Ni, Mn, Al, Ag, and V appear occasionally, mainly in sediments or biota, and trace elements such as Th, U, and other rare elements are detected rarely, often near mining or uranium deposits. Across environmental matrices, reported concentration ranges vary widely among studies, with particularly high levels in sediments and soils near mining and industrial areas, where some individual studies reported concentrations exceeding international guideline values. Elevated concentrations were also observed in food, beverages, cosmetics, medicinal plants, water, and aquatic biota, highlighting potential exposure pathways through dietary, dermal, and environmental contact. However, these findings are derived from heterogeneous studies and should not be interpreted as nationally representative quantitative estimates. Patterns of bioaccumulation reported in several individual studies, particularly in plants and aquatic organisms, further underscore ecological and human health concerns; however, this review summarizes reported observations rather than performing a quantitative meta-analysis of bioaccumulation factors. This review is nationally and internationally relevant, given Tanzania’s extensive mining activities and long Indian Ocean coastline, linking environmental contamination to broader regional and global ecosystems. The study identifies key research gaps, including limited monitoring of highly toxic elements, underrepresented marine ecosystems, and uneven geographic distribution of studies across the country. The study also recommends the use of advanced analytical techniques, such as ICP-MS, for analyzing trace and ultra-trace metals. The findings provide a critical reference for environmental monitoring, public health interventions, and sustainable management of heavy metal pollution in Tanzania.
The Southwest Indian Ocean (SWIO) is an area accounting for about 11 This study examined the cross-seasonal impacts of austral summer tropical cyclones (TCs) over the Southwest Indian Ocean (SWIO) on rainfall patterns in East Africa during the subsequent austral autumn, using gauge-interpolated CRU precipitation, ERA5 reanalysis, TCs from IBTrACS, and NOAA ERSST data from 1981 to 2021. Statistical techniques, including correlation, regression and composite analysis, were applied to investigate the linkage and associated mechanism between Tropical Cyclone Frequency (TCF) and rainfall. Additionally, an empirical linear regression model was constructed using predictors of austral summer TCF and SST indices to predict East African rainfall in the following austral autumn. The findings suggest that increased tropical cyclone activity over the SWIO can trigger large-scale atmospheric circulation, resulting in wetter conditions in East Africa. Indeed, the regression model incorporating the TCs revealed an improved prediction skill for rainfall, suggesting that the TCs might serve as important precursory signals for rainfall conditions over East Africa. These findings offer a new insight into the interaction between extratropical and tropical climatic systems and provide a potential signal for seasonal rainfall predictions, which could support improved planning and disaster preparedness in the region. Tropical cyclone (TC) activity peaks during the austral summer (January–February-March), driven by high sea surface temperature (SST) and moist atmospheric conditions. A significant positive correlation exists between January-February-March TC Frequency (TCF) and East Africa’s rainfall in the subsequent months of March-April-May. Increased TC activity stimulates high-level anticyclonic circulation anomalies over eastern Madagascar, coupled with the lower-level moist southerlies, which lead to moist conditions in East Africa, associated with increased rainfall. A multivariate regression model combining January-February-March TCF and SST indices suggests improved forecasts of rainfall in subsequent March-April-May.
Abstract This perspective paper examines transition pathways that move small‐scale fisheries from vulnerability towards viability. We understand ‘vulnerability to viability transition pathways’ as integrative and one that extends beyond economic concerns to include social, political, cultural and ecological aspects of small‐scale fisheries. Our findings draw on a reflexive and qualitative assessment of country‐specific case studies from across Africa and Asia to collaboratively identify transition pathways reflected in these contexts. Common pathways that emerged included: (1) building governance networks and partnerships; (2) centring small‐scale fisheries tenure and rights; (3) advancing a gender and intersectional perspective on viability pathways; (4) enhancing opportunities for ecologically sensitive and diversified livelihoods; and (5) co‐creating and co‐producing the knowledge required to catalyse transition pathways. Outcomes of this analysis provide context‐specific foundations upon which to further co‐develop a research agenda on small‐scale fisheries vulnerability to viability transitions. Insights from this analysis also contribute to the identification of the transdisciplinary capacities needed to build more viable and resilient small‐scale fisheries in the context of ongoing debates about blue economy expansion, and in relation to country‐level commitments to implement provisions of the FAO small‐scale fisheries guidelines. In advancing a vulnerability to viability pathways lens, this paper frames small‐scale fisheries transitions as governance‐mediated, justice‐oriented, relational and inherently non‐linear processes. Read the free Plain Language Summary for this article on the Journal blog.
