Influence of Environmental Factors on the Seasonal Dynamics of Nitrogen and Phosphorus in Fresco Lagoon, Côte d’Ivoire | Chapter 5 | Current Research on Geography, Earth Science and Environment Vol. 3

 

The Fresco lagoon, one of the essential components of the Ivorian lagoon system and located in the southwest of Côte d'Ivoire, contributes to the economic and tourist development of the country. This study, conducted from June 2019 to May 2020, highlights the strong pressure that the Fresco lagoon is under due to human activities in its watershed. Pollutants from these activities, mainly consisting of organic matter, are released into the natural environment without prior treatment. Then, the mineralisation of organic matter, influenced by the physicochemical factors of the water, leads to a phenomenon of eutrophication, due to the enrichment of the water with nitrogen and phosphorus. Eutrophication is one of the causes of mortality of aquatic biodiversity due to low dissolved oxygen levels. The objective of this study is to monitor the seasonal dynamics of nitrogen and phosphorus nutrients in the waters of two locations in the Fresco lagoon, designated Zone I and Zone II. To do this, the physicochemical parameters were determined using a multiparameter and the ammonium (NH4+), nitrite (NO2-), nitrate (NO3-) and phosphate (PO43-) contents by spectrophotometric assay. The statistical components such as the mean (m), the standard deviation (s), the coefficient of variation (CV (%)), the minimum value (Min), the maximum value (Max) and the normalised principal component analysis (NPCA) were assessed. The results reveal high temperatures in the long dry season (32.04±0.52°C in zone I and 30.59±0.90°C in zone II), low dissolved oxygen contents in the short rainy season (1.40±0.43mg/L in zone I and 1.78±0.06 mg/L in zone II) and acidic waters in the long rainy season (pH = 6.25±0.08 in zone I and pH = 6.31±0.53 in zone II). Nitrate (16.77±9.82 mg/L) and phosphate (3.28±3.20 mg/L) levels in Zone II are relatively high during the short rainy season and the long dry season, respectively. These high levels characterise a eutrophic environment. Decontamination of wastewater before its discharge into nature, regular monitoring of the health of this ecosystem and public awareness of environmental protection could contribute to improving water quality.

 

 

Author(s) Details

Yè Nicaise OUATTARA
Laboratoire de Constitution et Réaction de la Matière (LCRM) de l’Université Félix Houphouët-Boigny, 22 BP 582 Abidjan 22, Côte d’Ivoire.

 

Ake Pierre AKE
Laboratoire de Constitution et Réaction de la Matière (LCRM) de l’Université Félix Houphouët-Boigny, 22 BP 582 Abidjan 22, Côte d’Ivoire.

 

Adama Diarrassouba TUO
Centre de Recherches Océanologiques (CRO), 29, Rue des Pêcheurs – BP. V 18 Abidjan, Côte d’Ivoire.

 

Albert TROKOUREY
Laboratoire de Constitution et Réaction de la Matière (LCRM) de l’Université Félix Houphouët-Boigny, 22 BP 582 Abidjan 22, Côte d’Ivoire.

 

Please see the book here :- https://doi.org/10.9734/bpi/crgese/v3/6430