Increasing anthropogenic stressors influenced the water quality and shifted trophic status of northern Lake Tana Gulf, Ethiopia

Nutrients in an aquatic system determine productivity, integrity and ecological status of the aquatic system. However, the excessive enrichment of these nutrients emanating from severe anthropogenic activity has substantially impacted water quality and biodiversity. There is diminutive information a...

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Main Authors: Flipos Engdaw, Tadesse Fetahi, Demeke Kifle
Format: Article
Language:English
Published: Elsevier 2025-01-01
Series:Heliyon
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Online Access:http://www.sciencedirect.com/science/article/pii/S2405844024171939
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author Flipos Engdaw
Tadesse Fetahi
Demeke Kifle
author_facet Flipos Engdaw
Tadesse Fetahi
Demeke Kifle
author_sort Flipos Engdaw
collection DOAJ
description Nutrients in an aquatic system determine productivity, integrity and ecological status of the aquatic system. However, the excessive enrichment of these nutrients emanating from severe anthropogenic activity has substantially impacted water quality and biodiversity. There is diminutive information available on the water quality and trophic status of the northern Gulf of Lake Tana, Ethiopia due to accessibility difficulties. Therefore, this study aimed to assess the spatio-temporal changes in water quality and trophic status of Lake Tana, specifically the Gulf of Gorgora. Samples were collected from five sampling points between May 2023 to April 2024, and sampling sites were selected based on their proximity to human interference. The physico-chemical parameters were measured in situ or determined in water samples using standard methods. There were significant (p < 0.05) variations in temperature, dissolved oxygen (DO), electrical conductivity (EC) and turbidity between the dry and rainy seasons. The mean concentrations of nutrients such as NO3-N (0.48 mg/l), soluble reactive phosphorus (SRP) (1.2 mg/l) total nitrogen (TN) (1.27 mg/l), and total phosphorus (TP) (2.1 mg/l), showed significant spatio-temporal variations, with higher concentrations recorded at the Megech and Dablo sites during the rainy seasons. The depth-wise distributions of the parameters exhibited a consistent pattern, with a slight increase in the levels of EC, turbidity, TP, and TN, and a decrease in temperature, DO and NO3-N. The concentrations of SRP, TP, and TN, were slightly higher than the USEPA's threshold concentrations for causing eutrophication. The shift in the trophic status of Lake Tana from oligo-mesotrophic to eutrophic is likely due to nutrient enrichment associated with anthropogenic stressors. Therefore, continuous monitoring is essential to avert future ecological imbalances in the lake.
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spelling doaj-art-4082755cbfb94b78924886fd37dffeee2025-01-17T04:50:21ZengElsevierHeliyon2405-84402025-01-01111e41162Increasing anthropogenic stressors influenced the water quality and shifted trophic status of northern Lake Tana Gulf, EthiopiaFlipos Engdaw0Tadesse Fetahi1Demeke Kifle2African Center of Excellence for Water Management, Addis Ababa University, 1176, Addis Ababa, Ethiopia; Department of Biology, College of Natural and Computational Sciences, University of Gondar, 196, Gondar, Ethiopia; Corresponding author. African Center of Excellence for Water Management, Addis Ababa University, 1176, Addis Ababa, Ethiopia.Department of Zoological Sciences, Addis Ababa University, 1176, Addis Ababa, EthiopiaDepartment of Zoological Sciences, Addis Ababa University, 1176, Addis Ababa, EthiopiaNutrients in an aquatic system determine productivity, integrity and ecological status of the aquatic system. However, the excessive enrichment of these nutrients emanating from severe anthropogenic activity has substantially impacted water quality and biodiversity. There is diminutive information available on the water quality and trophic status of the northern Gulf of Lake Tana, Ethiopia due to accessibility difficulties. Therefore, this study aimed to assess the spatio-temporal changes in water quality and trophic status of Lake Tana, specifically the Gulf of Gorgora. Samples were collected from five sampling points between May 2023 to April 2024, and sampling sites were selected based on their proximity to human interference. The physico-chemical parameters were measured in situ or determined in water samples using standard methods. There were significant (p < 0.05) variations in temperature, dissolved oxygen (DO), electrical conductivity (EC) and turbidity between the dry and rainy seasons. The mean concentrations of nutrients such as NO3-N (0.48 mg/l), soluble reactive phosphorus (SRP) (1.2 mg/l) total nitrogen (TN) (1.27 mg/l), and total phosphorus (TP) (2.1 mg/l), showed significant spatio-temporal variations, with higher concentrations recorded at the Megech and Dablo sites during the rainy seasons. The depth-wise distributions of the parameters exhibited a consistent pattern, with a slight increase in the levels of EC, turbidity, TP, and TN, and a decrease in temperature, DO and NO3-N. The concentrations of SRP, TP, and TN, were slightly higher than the USEPA's threshold concentrations for causing eutrophication. The shift in the trophic status of Lake Tana from oligo-mesotrophic to eutrophic is likely due to nutrient enrichment associated with anthropogenic stressors. Therefore, continuous monitoring is essential to avert future ecological imbalances in the lake.http://www.sciencedirect.com/science/article/pii/S2405844024171939Anthropogenic stressorEutrophicationNutrient enrichmentPollutionTrophic statusWater quality
spellingShingle Flipos Engdaw
Tadesse Fetahi
Demeke Kifle
Increasing anthropogenic stressors influenced the water quality and shifted trophic status of northern Lake Tana Gulf, Ethiopia
Heliyon
Anthropogenic stressor
Eutrophication
Nutrient enrichment
Pollution
Trophic status
Water quality
title Increasing anthropogenic stressors influenced the water quality and shifted trophic status of northern Lake Tana Gulf, Ethiopia
title_full Increasing anthropogenic stressors influenced the water quality and shifted trophic status of northern Lake Tana Gulf, Ethiopia
title_fullStr Increasing anthropogenic stressors influenced the water quality and shifted trophic status of northern Lake Tana Gulf, Ethiopia
title_full_unstemmed Increasing anthropogenic stressors influenced the water quality and shifted trophic status of northern Lake Tana Gulf, Ethiopia
title_short Increasing anthropogenic stressors influenced the water quality and shifted trophic status of northern Lake Tana Gulf, Ethiopia
title_sort increasing anthropogenic stressors influenced the water quality and shifted trophic status of northern lake tana gulf ethiopia
topic Anthropogenic stressor
Eutrophication
Nutrient enrichment
Pollution
Trophic status
Water quality
url http://www.sciencedirect.com/science/article/pii/S2405844024171939
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