Trawl Net Design and Fish Welfare

Trawl net design affects both the welfare of target fish species during capture and the survival probability of bycatch species, with evidence-based modifications significantly reducing suffering in both categories.

Key Facts

Fish in trawl nets experience progressive hypoxia as oxygen depletes over the tow duration
Pressure changes during haul-up cause swim bladder rupture in demersal species
Escape panels and modified mesh sizes allow undersized fish to exit before capture
Reduced tow duration and improved net design reduce injury and mortality in both target and bycatch species
Net cameras enable researchers to assess fish behavior inside trawls for welfare assessment

Welfare Considerations

Fish caught in trawls experience a prolonged capture process involving oxygen depletion, physical compression, and pressure changes over tow durations that can last hours. The welfare cost depends heavily on tow duration and net design. Short tow times and modified nets that allow smaller fish to escape reduce both the intensity and duration of the welfare harm. Net camera technology is enabling direct observation of fish welfare inside trawls for the first time, providing evidence for design improvements.

What You Can Do

Support campaigns for maximum tow duration limits in trawl fisheries
Choose seafood from fisheries with documented reduced-impact trawl designs
Advocate for mandatory net camera programs in commercial trawl fisheries
Donate to bycatch reduction research including welfare-improving net design
Raise awareness about trawl capture welfare as part of the fish welfare discussion