Biodiversity and Spatial Distribution of Zooplankton in Gold-Mining Areas of the Cavally River (Côte d’Ivoire)
Attoubé Ida MONNEY *
Laboratory of Biodiversity and Tropical Ecology, Faculty of Environment, Jean Lorougnon Guédé University, Daloa, Côte d’Ivoire.
Olga Rosemonde N’DRI
Laboratory of Biodiversity and Tropical Ecology, Faculty of Environment, Jean Lorougnon Guédé University, Daloa, Côte d’Ivoire.
Jean-Renaud ALLOUKO
Laboratory of Biodiversity and Tropical Ecology, Faculty of Environment, Jean Lorougnon Guédé University, Daloa, Côte d’Ivoire.
Kouakou Jean-Baptiste ABO
Laboratory of Biodiversity and Tropical Ecology, Faculty of Environment, Jean Lorougnon Guédé University, Daloa, Côte d’Ivoire.
Guy-Melaine DAGO
Laboratory of Biodiversity and Tropical Ecology, Faculty of Environment, Jean Lorougnon Guédé University, Daloa, Côte d’Ivoire.
Tidiani KONE
Laboratory of Biodiversity and Tropical Ecology, Faculty of Environment, Jean Lorougnon Guédé University, Daloa, Côte d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
In a context where artisanal gold mining durably alters river ecosystems, this study analyzes the effect of gold panning on the diversity and structure of the planktonic fauna of the Cavally River. Zooplankton was sampled monthly from January to May 2025 using a plankton net with a 55 µm mesh size. The inventory of the zooplankton community identified a total of 40 taxa, distributed as follows: Rotifers (34 taxa), Copepods (2 taxa), Cladocerans (1 taxa) and other groups of organisms (3 taxa). The community was largely dominated by Rotifers, which represented 85% of the total density. Zooplankton diversity (31 taxa) and abundance (6444.44 ind·m⁻³) were higher at Niampleu, a station not affected by illegal gold-mining activity. The environmental variables that most strongly influenced taxonomic diversity and abundance were temperature, dissolved oxygen, transparency, and pH.
Keywords: Zooplankton, diversity, structure, illegal gold mining, Cavally River