Contribution à l'étude de la biodiversité au niveau de quelques sites de la zone côtière de Mostaganem

Abstract

This study contributes to the inventory of algal biodiversity at two coastal sites in the Mostaganem region (Stidia and Petit Port) in order to assess their ecological status. To achieve this objective, field sampling and phytosociological surveys were carried out, and several analytical, synthetic, and ecological indices were calculated, including Shannon, Pielou, and Sorensen indices. The results revealed nearly similar species richness between the two study sites, with 14 species recorded at Stidia and 13 species at Petit Port. Ulva lactuca was the most frequent species at Stidia, followed by Ulva rigida and Cystoseira compressa, whereas Ulva intestinalis and Padina pavonica were the most common species at Petit Port. The Chlorophyta group was dominant at Stidia, while both Chlorophyta and Ochrophyta dominated at Petit Port. The Shannon diversity index reached 2.71 at Stidia and the Pielou index 0.71, indicating a moderate ecological status and a non-uniform distribution of species. At Petit Port, the Shannon index was 3.10 and the Pielou index 0.83, reflecting a moderate ecological status with a more even species distribution. The Sorensen index (0.66) indicated a slight dissimilarity between the two sites. This study provides valuable information on the algal biodiversity of the Mostaganem coastal area and highlights the importance of continuous monitoring to preserve these fragile ecosystems.