Research Information System
Journal of Coastal Conservation, vol.29, no.4, 2025 (SCI-Expanded)
Anthropogenic activities and coastal development significantly alter marine ecosystems. To access role of microbes as nature-based solutions across genetic, functional and ecological levels, with a focus on biofilm formation as a control mechanism in aquatic environment, a field campaign was conducted along Karachi coast from 2022 to 2023. Seawater and sediment samples were collected from nine human-impacted sites to study role of sediments and bacteria in sedimentary environment. Grain size and elemental composition results showed distinct sediment types at different sites, influenced by human activities. Si-enriched mud of siliceous biogenous origin was dominant due to marinas for storage, access of boasts in harbor, golf club on Korangi and desalination plants on Clifton beach. China and Gizri shifted to Ca enriched granules of calcareous biogenic origin sediment due to mangrove removal leading to abundance of fossils, construction of boardwalks, break walls and leisure-oriented clubs. Bacterial load was higher at sand-clay sites (0.42 × 105 cells/mL) compared to pebble sites (0.31 × 105 cells/mL). Analysis finding showed 60% of microorganisms exhibit high adherence properties, forming 3D biofilms that act as battlefront for sediment stability and restoration. Oxygen, temperature and pH are key factors that facilitate physical microbial-mineral interactions and adhesion within microbial communities by pili for biofilm formation. Time scale analysis showed that biofilm development occurred within first hour of surface contact, reaching maturity within 48 h. This paper validates developmental impacts, highlights the significance of bacterial biofilms in sediment restoration and offers clear insights for authorities to implement measures for preserving marine ecosystem.