Assessment of water quality in the lower Nyong estuary (Cameroon, Atlantic Coast) from environmental variables and phytoplankton communities composition

Mama, Anselme Crépin; Ghepdeu, Gisele Flodore Youbouni; Ndam, Jules RÃ©mi Ngoupayou; Bonga, Manfred Desire; Onana, Fils Mammert; Onguene, RaphaÃ«l

doi:10.5897/ajest2017.2454

Cited by 11 publications

(15 citation statements)

References 19 publications

(19 reference statements)

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“…Our study found high correlations between phytoplankton diversity indices and environmental variables of nutrients and nutrient ratios in the Jiulong River estuary, indicating that nutrients and nutrient ratios contributed significantly to phytoplankton biodiversity patterns, which is in agreement with findings from previous studies conducted in similar estuarine environments (Schoor et al, 2008;Li et al, 2010;Huang et al, 2013;Chu et al, 2014;Zhang et al, 2015;Anselme et al, 2018). The relative contribution was quantified by calculating the percentage of the absolute coefficient value of all relevant variables that yielded a statistically significant value (p < 0.001) from optimal regression equations (see Figures 9, 10).…”

Section: Roles Of Nutrients and Nutrient Ratios In Shaping Phytoplank...supporting

confidence: 92%

Phytoplankton Species Diversity Patterns and Associated Driving Factors in China’s Jiulong River Estuary: Roles That Nutrients and Nutrient Ratios Play

Chen

et al. 2022

Front. Mar. Sci.

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Understanding diversity patterns and associated driving factors are the critical topics in macroecology and conservation biology. Phytoplankton are highly susceptible to environmental changes in estuaries, particularly eutrophication. This study examined phytoplankton alpha and beta diversity using investigation data in May (springtime), August (summer) and November (autumn) 2009 in China’s Jiulong River estuary, where it was easily polluted because of considerable discharge from a highly dense human population and low self-purification capacity with its limited river basin area, potentially resulting in eutrophication and then influencing phytoplankton diversity. Potential influencing factors were also explored, including dissolved oxygen, salinity, nutrients, nutrient ratios, geographic and hydrologic distance, and so on. The results indicated that Shannon’s index (H’) and Pielou’s index (J) decreased from the estuary’s upper to middle and then increased from middle to lower reaches, Simpson’s (D) observed the opposite trend and species number (S) gradually increased from the estuary’s upper to lower reaches. For beta diversity, all the indices showed a gradual decrease trend from the estuary’s upper to lower reaches, where also, turnover dominated beta diversity for all seasons. It is noteworthy that the significant roles that nutrients and nutrient ratios played in shaping phytoplankton diversity patterns and the nutrient balance were characterized by excess nitrogen (N) and silicon (Si) and limited phosphorus (P), which could potentially cause diatom blooms. Findings also showed that decreasing Si concentrations can help to reduce overall pollution levels as well as the restoration of the estuary’s ecosystem better than just reducing N alone. Accordingly, this study advocates for the protection of the entire estuary system with particular emphasis on its upper reaches. Moreover, greater attention should also be paid to impacts associated with N input and nutrient ratio trade-offs to the prospective watershed management of this estuary. This study provides a practical approach to explore estuarine diversity in a comprehensive way, which can inform effective biodiversity conservation and also be applied to other marine ecosystems to better guide sustainable management and conservation practices.

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Section: Roles Of Nutrients and Nutrient Ratios In Shaping Phytoplank...supporting

confidence: 92%

Phytoplankton Species Diversity Patterns and Associated Driving Factors in China’s Jiulong River Estuary: Roles That Nutrients and Nutrient Ratios Play

Chen

et al. 2022

Front. Mar. Sci.

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“…The Nyong estuary is part of the Campo-Nyong hydrosystem of the Atlantic Meridional Coast of Cameroon. Unlike rivers located in the North coast and like all rivers located in Cameroon's South Atlantic the Nyong river like is less watered and subject to an equatorial climate with four seasons which are the long rainy season (LRS), short rainy season (SRS), the long dry season (LDS) and short dry season (SDS) [15] [29] [36]. Climate is influenced by Southwest monsoon, limited on average speed to 10km/h because of the highly developed rainforest [29].…”

Section: Study Area and Sampling Stationsmentioning

confidence: 99%

“…During water quality monitoring, it is very important to assess the physicochemical parameters of water in space and time. Biogeochemical variables and biotics data are usually gathered; several techniques have already been implemented to analyze water quality data, such as data reduction techniques [7] [8] [9] [10] [11], water quality index (WQI) [12] [13] [14] [15], univariate data analysis method, and estuary health index (EHI) [16]. Data reduction techniques usual-ly used to simplify the process of interpreting large datasets.…”

Section: Introductionmentioning

confidence: 99%

“…Its lower course crosses the Douala-Edea Terrestrial and Marine Park, where active fishing is developed in mangrove area. Intensive agriculture is practiced on the banks of its middle course, while offshore oil and gas activities are developed in the vicinity [15]. These anthropogenic activities associated to mangrove and rainforest have increased nutrient input and as such excessive nutrient loading has accelerated primary production (eutrophication), accumulation of organic matter, increased turbidity, and excessive oxygen consumption.…”

Section: Introductionmentioning

confidence: 99%

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Understanding Seasonal and Spatial Variation of Water Quality Parameters in Mangrove Estuary of the Nyong River Using Multivariate Analysis (Cameroon Southern Atlantic Coast)

Mama¹,

Bodo²,

Ghepdeu³

et al. 2021

OJMS

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To evaluate the actual status of water quality and conclude on the mains source of pollution in the Nyong estuary River, seasonal and spatial variation of water quality parameters was interpreted by multivariate statistical techniques (Principal Component analysis). Nine (09) environmental variables were monitored at four surface stations in the estuary for two seasonal cycles. The fieldwork was conducted from 2018 to 2019 during high tide and low tide for each survey. In situ physical parameters were measured for a total of 64 samples (32 samples for each tide). The laboratory works consisted of some physicochemical analyses and processing of these data by descriptive and multidimensional statistical analyses. Temperature, suspended particle matter, nitrate, nitrite and phosphate change significantly in the estuary with season (p < 0.05), while salinity, dissolved oxygen, pH, and ammonium do not vary significantly with season (p > 0.05). Principal Component analysis found temperature, salinity, pH, ammonium to be the most important parameters contributing to the fluctuations of surface water quality in the Nyong estuary during the dry seasons whereas suspended particle matter, nitrate, and phosphate are the most important parameters contributing to the fluctuation of surface water quality in the Nyong estuary during the rainy seasons. Based on spatial variation, the Principal Component analysis found that, sus-

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“…However, very few studies specific to water quality in these environments have been carried out despite all the services provided. Existing information concerns the quantitative approach to biodegradation in the freshwater-saltwater mixing zone in the Sanaga and Nyong estuaries, and in the rivers of the Douala Bay (Giresse & Cahet 1997;Fonge et al 2013;Mama et al 2018;Mama et al 2021).…”

Section: Introductionmentioning

confidence: 99%

Effects of the tide on the temporal and spatial physicochemical structure of the Kienké river estuary (South Atlantic Coast of Cameroon, Kribi) and its phytoplankton

Mama

Ghepdeu²,

Tankoua³

et al. 2023

OandHS

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The present work aimed to understand the physicochemical and phytoplanktonic structure of the Kienke estuary water in the urban area of Kribi town in relation to human activities and fluvial or oceanic influences. Field investigations and laboratory work were devoted to the sampling and measurement of some physicochemical and biological parameters, specific treatments and classical statistics (descriptive, multidimensional) of variables. Estuary water is characterised by an instability and spatiotemporal variations in its physicochemical parameters. The most sensitive parameters are as follows: a temperature ranging between 22.6°C and 31°C under the influence of atmospheric variations, electrical conductivity and salinity that are relatively high (0.22 < C. E < 49.70 mS cm-1; avg =16.56 mS cm-1; 0 < Sal < 29.32 PSU; avg = 11.51 PSU), and a pH that is overall acidic to basic (6 < pH < 8.86; avg = 7.75 ± 0.82). The nutrients variation (ammonium, nitrite, nitrate and orthophosphate) is very low in space and time, with a longitudinal distribution controlled by tidal flows, river flows and the biological pump. For the 64 samples collected, 167 phytoplankton taxa were identified. The most abundant (36.36%) were Chrysophyta Division, followed by Chlorophyta. Species richness is marked by brackish water taxa. According to this structure and the combination of both gradients, mineratilisation and organic matter enrichment is of a physicochemical typology, and the biotypology is hydrotypologically dependent.

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Assessment of water quality in the lower Nyong estuary (Cameroon, Atlantic Coast) from environmental variables and phytoplankton communities composition

Cited by 11 publications

References 19 publications

Phytoplankton Species Diversity Patterns and Associated Driving Factors in China’s Jiulong River Estuary: Roles That Nutrients and Nutrient Ratios Play

Phytoplankton Species Diversity Patterns and Associated Driving Factors in China’s Jiulong River Estuary: Roles That Nutrients and Nutrient Ratios Play

Understanding Seasonal and Spatial Variation of Water Quality Parameters in Mangrove Estuary of the Nyong River Using Multivariate Analysis (Cameroon Southern Atlantic Coast)

Effects of the tide on the temporal and spatial physicochemical structure of the Kienké river estuary (South Atlantic Coast of Cameroon, Kribi) and its phytoplankton

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