Ecological Survey of Coral Reef Conditions Along the Bonny Coastline, Rivers State, South South Nigeria

Coastal ecosystems along the Niger Delta are among the most productive and threatened marine environments in West Africa. This study conducted an ecological survey of coral reef and hard substrate communities along the Bonny coastline in Rivers State, assessing the extent and condition of reef habitats. Belt transects were established along reef-slope and reef-flat zones at three sites. Coral cover, coral species diversity, and bleaching prevalence were estimated using the point intercept transect method. Associated fish and macroinvertebrate communities were surveyed using visual census techniques. Substrate composition, water temperature, salinity, and turbidity were recorded as environmental covariates. Results showed low live coral cover across all sites, averaging 9 percent, with heavy sedimentation and elevated turbidity identified as primary environmental stressors. Several colonies showed signs of bleaching consistent with thermal stress during the survey period. Fish diversity was moderate, dominated by demersal species tolerant of turbid, low-visibility conditions. Invertebrate diversity was low relative to reference conditions documented in historical ecological reports for the region. The study documents concerning reef degradation in the Bonny coastal zone and recommends a comprehensive marine spatial planning exercise incorporating reef protection zones, reduction of sedimentation through watershed management upstream, and prohibition of trawling in nearshore reef areas. Keywords: coral reef, Bonny coastline, reef degradation, Rivers State, Niger Delta.