Mangrove Vegetation Structure and Sediment Microbial Diversity Under Shoreline Disturbance at Iwofe Jetty, Port Harcourt, Nigeria

This study assessed the floristic composition and sediment microbial diversity of mangrove forests at Iwofe Jetty, Port Harcourt, Nigeria. Three belt transects (100 m × 10 m) were established at the study location (A, B, and C), with a control station located approximately 500m away. Vegetation and sediment samples were collected in triplicate. Species richness and diversity were determined using Margalef’s and Simpson’s indices, while standard microbiological methods were used to isolate and identify sediment microorganisms. A total of 1,046 individual plants belonging to the family Rhizophoraceae were recorded, comprising Rhizophora racemosa, R. harrisonii, and R. mangle. R. racemosa was dominant across all locations (47.32–55.21%), whereas R. mangle showed the lowest abundance (12.95–17.47%). The control site exhibited relatively higher species abundance and diversity. Location A recorded the lowest richness (0.376) and diversity (2.535), while Location B had the highest values (0.549 and 2.756). Sediment analysis revealed bacterial genera including Bacillus, Pseudomonas, Staphylococcus, Aeromonas, Streptococcus, and Micrococcus, as well as fungal genera such as Aspergillus, Rhizopus, Fusarium, and yeast species. Spatial variations suggest potential anthropogenic influence, highlighting the need for continuous ecological monitoring to maintain ecosystem stability.