Ståle Haaland
Research Scientist
Authors
Jirata Shiferaw Abosse Bekele Megersa Feleke Zewge Ståle Haaland Samuel Assefa Fasil Ejigu EregnoAbstract
No abstract has been registered
Authors
Berhanu Menasbo Tegegne Fasil Ejigu Eregno Ståle Haaland Gebremedhin Gebremariam Gebreegziabher Samuel Alemayehu Elias Assayehegn Abraha Gebrekidan Asgedom Emiru Birhane HizikiasAbstract
Tegegne BM, Eregno FE, Haaland SL, Gebreegziabher GG, Alemayehu S, Assayehegn E, Asgedom AG, Birhan E. 2026. Spatiotemporal assessment of nutrient pollution and water quality in Lake Hashenge, Ethiopia. Lake Reserv Manag. XXX–XXX. Nutrient enrichment is an increasing management concern in closed-basin lakes where limited water exchange increases vulnerability to eutrophication. This study assessed the spatial and seasonal dynamics of nutrient pollution in Lake Hashenge (LH), a highland crater lake in northern Ethiopia, from 2022 to 2023. Overall, 180 surface-water samples were collected from 15 monitoring sites during wet and dry seasons and analyzed for major physicochemical parameters, nitrogen (N) and phosphorus (P) species, and chlorophyll a (Chl-a). Multivariate statistical analyses of principal component analysis (PCA) and cluster analysis (CA) were used to identify dominant nutrient sources and spatial patterns, while the water quality index (WQI) and comprehensive pollution index (CPI) were applied to evaluate ecological condition. Results revealed pronounced seasonal variation, with higher nutrient concentrations and pollution indices during the dry season, likely driven by reduced inflow, evaporative concentration, and internal nutrient loading. Inflow-proximal and shoreline sites exhibited greater enrichment, reflecting agricultural runoff and grazing pressures. Chl-a concentrations indicated persistent hypertrophic conditions across seasons. CA identified 3 spatial pollution categories, demonstrating strong heterogeneity between littoral and central zones. Although mean pollution levels classified the lake as moderately degraded, localized hotspots and sustained phytoplankton biomass suggest progressive eutrophication risk. These findings provide management-relevant evidence supporting targeted watershed interventions, including runoff reduction, riparian buffer establishment, livestock access control, and strengthened land-use planning. The study demonstrates how integrated water-quality indices and multivariate analysis can inform adaptive lake management in data-limited tropical systems.
Abstract
Background: Campylobacter is an important water- and food-borne pathogen with notable genetic similarity among strains isolated from humans, animals, and environmental sources. This systematic review and meta- analysis synthesized available evidence on the prevalence, antimicrobial resistance, and associated risk factors of Campylobacter in humans, animals, and the environment in Ethiopia. Methods: Articles published from 1997 to 2024 were systematically searched and retrieved from PubMed, Science Direct, Web of Science, and Google Scholar. The review was conducted in accordance with the PRISMA guidelines, and data from eligible articles were extracted using a standardized data extraction template. Heterogeneity was evaluated using Cochran’s Q statistic, the I² statistic, and Egger’s test for small-study effects. Data extraction and analysis were conducted using Microsoft Excel and Stata 14. Results: Of the 11,573 samples analyzed across 26 studies, 3204 were positive for Campylobacter, yielding a pooled prevalence of 19.9 %. The highest prevalence was observed in environmental samples (33.4 %), followed by humans (31.4 %) and animals (24 %). Regionally, Oromia showed the highest prevalence (30.4 %), while Addis Ababa and Tigray reported the lowest (11.0 %). Cephalothin and ampicillin exhibited the highest antimicrobial resistance (100 %), whereas gentamicin showed the lowest (7.1 %). Campylobacter jejuni and Campylobacter coli were the most frequently identified species and demonstrated the highest resistance levels. Major risk factors for campylobacteriosis included frequent animal contact, consumption of undercooked or contaminated food and water, and low parental education levels among affected children. Conclusion: This study highlights the distribution and increasing prevalence of Campylobacter and associated antimicrobial resistance within a One Health framework. Future research should encompass wider geographic coverage and include diverse sources such as poultry, companion animals, vegetables, and wastewater to generate more comprehensive epidemiological data. Such efforts will help address existing knowledge gaps and support the development of targeted interventions to reduce foodborne infections and mitigate antimicrobial resistance.