Bottom Trawling: Seafloor Destruction and Marine Animal Welfare

Bottom trawling is one of the most destructive fishing methods, causing mass mortality of non-target marine species and destroying the habitats that sustain ocean biodiversity.

Key Facts

Bottom trawls drag weighted nets across the seafloor, crushing corals, sponges and other habitat-forming species
An estimated 25-40% of the global catch from bottom trawling is discarded as bycatch after death or injury
A single trawl pass can destroy decades of cold-water coral growth that provides essential habitat for fish nurseries
Deep-sea trawling below 800 metres disturbs sediments containing thousands-year-old benthic communities
The EU has proposed banning bottom trawling in marine protected areas, though implementation has been delayed
Alternative fishing methods including longlines, traps and mid-water trawls reduce seafloor contact significantly
Some countries including Belize have implemented national bottom trawl bans with measurable ecosystem recovery

Welfare Considerations

Bottom trawling creates animal welfare harms at an almost incomprehensible scale. Non-target species including corals, sponges, brittle stars and countless invertebrates are crushed or fatally damaged in the net path. Target fish and bycatch species are subjected to extended capture distress, barotrauma from rapid pressure changes, and crushing in heavy catches before sorting. Discarded bycatch is returned dead or dying. Beyond individual animal welfare, the destruction of seafloor habitat removes the ecological foundation supporting vast numbers of marine animals across generations. Reducing bottom trawling intensity is simultaneously one of the most important welfare and conservation interventions available in marine policy.

What You Can Do

Choose seafood certified by schemes that exclude bottom-trawled fish from their supply chains
Support campaigns for effective marine protected area enforcement banning bottom trawling
Ask your retailer and restaurant what fishing methods were used to catch the seafood they sell
Advocate for government support for transitioning trawl-dependent fishing communities to lower-impact methods
Raise public awareness of bottom trawling by sharing accessible information about its scale and impact