Research Article
Development of a Macroinvertebrate Multimetric Index for the Evaluation of the Ecological Quality of Lake Nokoué
Houéyi Bénédicta Priscilia Capo-Chichi*
,
Delphine Adandedjan,
Thierry Matinkpon Agblonon Houelome,
Philippe Adédjobi Laleye,
Antoine Chikou,
Christophe Kaki,
Hyppolite Agadjihouede
Issue:
Volume 12, Issue 5, October 2024
Pages:
98-110
Received:
2 April 2024
Accepted:
27 May 2024
Published:
20 September 2024
Abstract: Nowadays, new tools for assessing the biotic integrity of aquatic environments are used. In Benin, the Macroinvertebrate MultiMetric Lake Index (M3LI) was designed to reveal the current state of Lake Nokoué. The inventory was carried out in eight seasonal data collection campaigns from 2019 to 2021 using an Eckman type grab and a trouble net. The composition, diversity and different metrics were calculated. Thirty-nine metrics grouped into five categories were defined and subjected to selection using a PCA in order to identify the relevant metrics for calculating the index. In the lake, 83 taxa divided into 25 orders and 54 families representing 32,770 specimens were determined. Insects, Molluscs, Crustaceans and Annelids constituted the essential macrofauna which was numerically dominated by Gastropods, Crustaceans, Bivalves and Insects. Of the 5 food functional groups obtained, crushers and collector-gatherers were dominant. Ten metrics relevant and well explained by environmental variables were used to calculate M3LI. The M3LI calculated varied from 6.44 at the station near Dantokpa to 3.38 at the Cotonou channel station with fluctuating water quality between poor quality and good quality. These results clearly explain the responses of the living communities of the lake faced with the various stresses due to daily marine intrusion, the role of receptacle of different continental waters and the various anthropogenic activities plunging the environment into a hypereutrophic state. It is therefore urgent to take measures to restoration of this environment to allow living species to regain their balance of life. This index is also a departure for the establishment of a biomonitoring program for the restoration of the lake.
Abstract: Nowadays, new tools for assessing the biotic integrity of aquatic environments are used. In Benin, the Macroinvertebrate MultiMetric Lake Index (M3LI) was designed to reveal the current state of Lake Nokoué. The inventory was carried out in eight seasonal data collection campaigns from 2019 to 2021 using an Eckman type grab and a trouble net. The c...
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Research Article
Trace Metal Elements (TMEs) in Groundwater Around the Former Industrial Gold Mine of Poura in Burkina Faso – West Africa
Issue:
Volume 12, Issue 5, October 2024
Pages:
111-124
Received:
10 September 2024
Accepted:
27 September 2024
Published:
29 October 2024
DOI:
10.11648/j.ijema.20241205.12
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Abstract: The objective of this study is to assess the quality of groundwater around the first industrial mine in Burkina Faso, whose activities have been closed since 1999. The diagnosis of pollution by trace metal elements of groundwater around the old Poura gold mine was carried out through the determination of the contents of Trace Metal Elements (TME) at MP-AES and the measurements of the physicochemical parameters in situ on 38 samples of borehole water. These data made it possible to calculate the pollution risk index, to establish correlations between the different physicochemical parameters on the one hand and with the trace metal elements on the other hand, from the Pearson matrix and to carry out a multivariate statistical analysis, in particular that in principal components (PCA), with a view to determining the origin of the polluting elements. The results obtained made it possible to identify four samples of groundwater with an acidic pH (GWF18 (6.44), GWF19 (6.39), GWF23 (6.1) and GWP01 (5.99)) and 34 samples of groundwater whose Cd, Al, Fe, As, Pb, or Hg contents are higher than the standards in force in Burkina Faso. The Pollution risk Index (PI) indicates that 35 groundwater samples are slightly polluted and 3 groundwater samples are very heavily polluted (GWP01 (PI = 456%), GWF06 (PI = 132.5%), GWF03 (PI = 105.1%)). The Pearson correlation matrix and the principal component analysis (PCA) show that the origin and mobilization of the trace metal elements involved (Al, As, Cd, Cr, Fe, Hg and Pb) are linked to natural mineralization and anthropogenic activities such as mining and agricultural activities, favored by the infiltration of water into the subsoil through geological structures such as fractures and faults.
Abstract: The objective of this study is to assess the quality of groundwater around the first industrial mine in Burkina Faso, whose activities have been closed since 1999. The diagnosis of pollution by trace metal elements of groundwater around the old Poura gold mine was carried out through the determination of the contents of Trace Metal Elements (TME) a...
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