SEASONAL CHANGES IN THE SPECIES COMPOSITION OF THE ICHTHYOFAUNA OF THE LITTORAL DELTA AND ESTUARY OF THE SENEGAL RIVER

  • A. V. Gushchin Shirshov Institute of Oceanology, Russian Academy of Sciences
  • M. Diop Permanent Secretariat of the Sub-Regional Fisheries Commission (CSRP)
DOI 10.29006/1564-2291.JOR-2025.53(3).5
Keywords Senegal River, delta, littoral, ichthyofauna, seasons, environmental conditions

Abstract

The littoral of the Senegal River delta and estuary below the Diama dam is home to 35 fish species belonging to freshwater, euryhaline and marine ecological complexes. The delta experiences two hydrological seasons associated with the period of monsoon rains: the rainy season and the dry season. During the rainy season, 26 fish species were encountered in the delta and estuary, and 17 species during the dry season. A list of littoral fish species is provided for 10 stations in a river bed, in a river branch, in a river channel, in a shallow lake, in an estuary, in lakes near the ocean, in the ocean. During the rainy season, the dominant species was the Guinea tilapia – Coptodon guineensis, and during the dry season, the catfish – Chrysichthys nigrodigitatus. The species composition and abundance of littoral fish are related to seasonal changes in water salinity in the delta and estuary, which, in addition to natural causes, is affected by regulated discharges of fresh water through the Diama dam. For the first time, the aim of the study was to study the species composition of littoral fish in the Senegal River below the Diama dam during the rainy season and dry season. Previously, the study of the ichthyofauna was based on commercial fish catches, without taking into account the most important ecological section of the river – the littoral, where juvenile fish are concentrated: 95.7 % of species – in the rainy season and 94.4 % of species – in the dry season.

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Published
2025-09-21
Issue
Vol 53 No 3 (2025): Journal of Oceanological Research
Section
Ecology of seas and oceans

Transfer of copyrights occurs on the basis of a license agreement between the Author and Shirshov Institute of Oceanology, RAS