First inventory of the composition and structure of the benthic macrofauna of the San-Pédro port basin’s darsine waters (South-West, Côte d’Ivoire)

Abstract

Port activities such as ship traffic and dredging of port basin's sediment can impact biological communities such as the benthos, the composition of which remains unknown. Moreover, the knowledge of the ivorian’s port basin benthic fauna is of concern to both scientists and port authorities in the development of their activities. This study carried out in July and December 2021, aimed to provide the first data on the composition of San-Pédro’s port basin benthic macroinvertebrates communities. For this purpose, four (4) sampling points were defined near the new wharf and in the central channel of this port. The measurements of the physical-chemical parameters of the darsine waters (temperature, salinity, turbidity, dissolved oxygen and lead content) were carried out in situ between 6 a.m. and 8 a.m. using a multiparameter. Benthic macroinvertebrates were collected with a Van Veen bucket with the help of two divers. The physical-chemical parameters indicated that the waters were oxygenated and turbid in the construction area of the new wharf. They were salty, warm, and rich in lead in the central channel. 39 species classified in 34 families, 25 orders, 07 classes, and 05 phyla. The phylum of mollusks (with 29 species) was the most preponderant. The distribution of macroinvertebrates was influenced by lead, turbidity, dissolved oxygen, salinity, and temperature. The benthos populations of port basin were lowly diversified and with a fairly balanced organization.