Role of environmental variables and seasonal mixing in dynamics of the phytoplankton community in a Tropical Highland Lake Ardibo, Ethiopia

AbstractThis study aimed to assess the spatial and seasonal variations of the phytoplankton community in response to environmental variables in Lake Ardibo. The study was done from October 2020 to September 2021 and physicochemical parameters such as water temperature, pH, dissolved oxygen, electric...

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Main Authors: Adem Mohammed, Seyoum Mengistou, Tadesse Fetahi
Format: Article
Language:English
Published: Taylor & Francis Group 2023-07-01
Series:Journal of Freshwater Ecology
Subjects:
Online Access:https://www.tandfonline.com/doi/10.1080/02705060.2023.2170484
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author Adem Mohammed
Seyoum Mengistou
Tadesse Fetahi
author_facet Adem Mohammed
Seyoum Mengistou
Tadesse Fetahi
author_sort Adem Mohammed
collection DOAJ
description AbstractThis study aimed to assess the spatial and seasonal variations of the phytoplankton community in response to environmental variables in Lake Ardibo. The study was done from October 2020 to September 2021 and physicochemical parameters such as water temperature, pH, dissolved oxygen, electrical conductivity, turbidity, alkalinity, Secchi-depth, nitrate, ammonium, silicon dioxide, soluble reactive phosphorus, and total phosphorus were measured using standard methods. ANOVA results indicated that all physicochemical parameters except turbidity had significant variation (p < 0.05) in all seasons. A total of 66 phytoplankton species grouped into seven phyla, including Bacillariophyta (23 taxa), Chlorophyta (21 taxa), Cyanophyta (14 taxa), Euglenophyta (3 taxa), Charophyta (2 taxa), Dinophyta (2 taxa) and Cryptophyta (1 taxon) were identified. Phytoplankton biomass showed significant spatial and seasonal variation with maximum cell density during the pre-rainy season, and low density in the main rainy season. Redundancy analysis (RDA) revealed that nutrients had a positive affinity with the phytoplankton community, whereas electrical conductivity, water temperature, and pH showed a negative relationship with phytoplankton abundance. Temporal rather that abiotic factors far influenced phytoplankton dynamics in this deep tropical lake. The analysis postulates that partial atelomixis during the pre-rainy months favors higher phytoplankton biomass with functional groups such as desmids and heavy diatoms contributing most during this mixing period, while wet season mixing depressed algal biomass due to increased turbidity with nutrients not being limiting during these times.
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spelling doaj.art-f1954e255c0a440ba133c9131cccfcf92023-12-12T20:20:41ZengTaylor & Francis GroupJournal of Freshwater Ecology0270-50602156-69412023-07-0138110.1080/02705060.2023.2170484Role of environmental variables and seasonal mixing in dynamics of the phytoplankton community in a Tropical Highland Lake Ardibo, EthiopiaAdem Mohammed0Seyoum Mengistou1Tadesse Fetahi2Africa Center of Excellence for Water Management, Addis Ababa University, Addis Ababa, EthiopiaAfrica Center of Excellence for Water Management, Addis Ababa University, Addis Ababa, EthiopiaAfrica Center of Excellence for Water Management, Addis Ababa University, Addis Ababa, EthiopiaAbstractThis study aimed to assess the spatial and seasonal variations of the phytoplankton community in response to environmental variables in Lake Ardibo. The study was done from October 2020 to September 2021 and physicochemical parameters such as water temperature, pH, dissolved oxygen, electrical conductivity, turbidity, alkalinity, Secchi-depth, nitrate, ammonium, silicon dioxide, soluble reactive phosphorus, and total phosphorus were measured using standard methods. ANOVA results indicated that all physicochemical parameters except turbidity had significant variation (p < 0.05) in all seasons. A total of 66 phytoplankton species grouped into seven phyla, including Bacillariophyta (23 taxa), Chlorophyta (21 taxa), Cyanophyta (14 taxa), Euglenophyta (3 taxa), Charophyta (2 taxa), Dinophyta (2 taxa) and Cryptophyta (1 taxon) were identified. Phytoplankton biomass showed significant spatial and seasonal variation with maximum cell density during the pre-rainy season, and low density in the main rainy season. Redundancy analysis (RDA) revealed that nutrients had a positive affinity with the phytoplankton community, whereas electrical conductivity, water temperature, and pH showed a negative relationship with phytoplankton abundance. Temporal rather that abiotic factors far influenced phytoplankton dynamics in this deep tropical lake. The analysis postulates that partial atelomixis during the pre-rainy months favors higher phytoplankton biomass with functional groups such as desmids and heavy diatoms contributing most during this mixing period, while wet season mixing depressed algal biomass due to increased turbidity with nutrients not being limiting during these times.https://www.tandfonline.com/doi/10.1080/02705060.2023.2170484Atelomixisnutrientsphytoplanktonspatial variationsseasonal variations
spellingShingle Adem Mohammed
Seyoum Mengistou
Tadesse Fetahi
Role of environmental variables and seasonal mixing in dynamics of the phytoplankton community in a Tropical Highland Lake Ardibo, Ethiopia
Journal of Freshwater Ecology
Atelomixis
nutrients
phytoplankton
spatial variations
seasonal variations
title Role of environmental variables and seasonal mixing in dynamics of the phytoplankton community in a Tropical Highland Lake Ardibo, Ethiopia
title_full Role of environmental variables and seasonal mixing in dynamics of the phytoplankton community in a Tropical Highland Lake Ardibo, Ethiopia
title_fullStr Role of environmental variables and seasonal mixing in dynamics of the phytoplankton community in a Tropical Highland Lake Ardibo, Ethiopia
title_full_unstemmed Role of environmental variables and seasonal mixing in dynamics of the phytoplankton community in a Tropical Highland Lake Ardibo, Ethiopia
title_short Role of environmental variables and seasonal mixing in dynamics of the phytoplankton community in a Tropical Highland Lake Ardibo, Ethiopia
title_sort role of environmental variables and seasonal mixing in dynamics of the phytoplankton community in a tropical highland lake ardibo ethiopia
topic Atelomixis
nutrients
phytoplankton
spatial variations
seasonal variations
url https://www.tandfonline.com/doi/10.1080/02705060.2023.2170484
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