Demersal Habitat Disturbance

Demersal habitat disturbance is physical alteration of the seabed and its near-bottom community by bottom-contact fishing gear, anchoring, dredging, or cable laying. Bottom trawls and dredges scrape and resuspend sediment, flatten biogenic structure, and kill or expose infauna and epifauna, shifting communities toward small, fast-growing opportunists. Recovery time ranges from months on mobile sand to decades or longer on slow-growing biogenic reefs and cold-water coral. It is assessed under the EU Marine Strategy Framework Directive 2008/56/EC Descriptor 6 (seafloor integrity) and managed through gear restrictions and bottom-trawl closures in vulnerable marine ecosystems.