Risso's Dolphin Welfare | Animal Welfare Hub

Risso's dolphins are distinctive, heavily scarred cetaceans found in deep offshore waters globally. Despite their wide range, their welfare faces threats from fishing interactions, noise, and climate change.

Key Facts

Risso's dolphins (Grampus griseus) are easily identified by their blunt heads and extensive white scarring from intraspecific tooth raking
They are obligate squid feeders, diving to hundreds of metres in search of cephalopod prey
Risso's dolphins are typically found in groups of 3-30, with some larger aggregations reported offshore
Bycatch in deep-water trawl and longline fisheries affects Risso's populations
They are known to strand occasionally - sonar disturbance is suspected in some mass strandings
Very little is known about their behaviour and welfare in the wild due to their offshore habitat
Risso's dolphins have been kept in captivity but are considered extremely poor candidates for captive management due to their specialized deep-sea diet

Welfare Considerations

Risso's dolphin welfare is largely invisible to humans due to their deep offshore habitat. The heavy scarring covering older individuals - caused by the teeth of other Risso's dolphins - suggests intense social interactions that may at times be painful. Captive Risso's dolphins have fared poorly, typically dying within weeks due to inability to adapt to prepared fish diets and the stress of shallow, confined environments. This argues strongly against any future captive display programs involving this species.

What You Can Do

Support campaigns to reduce deep-water trawling that causes cetacean bycatch
Advocate for acoustic monitoring of offshore waters to detect Risso's dolphin presence before sonar exercises
Choose sustainable seafood certified to minimise deep-water cetacean bycatch
Follow ORCA's surveys of UK offshore waters for sightings data and conservation priorities