Companion Animals

Koi Pond Welfare

Koi fish in garden ponds are often kept without adequate filtration space or winter preparation.

Key Facts

Evidence-based approaches to koi pond welfare inform welfare improvements globally
Animal welfare science provides tools to assess and improve conditions for all species
Individual consumer choices combined with advocacy create lasting systemic change
Every action to reduce animal suffering contributes to a more compassionate world

Welfare Considerations

Koi can live 30 to 50 years and grow large requiring substantial pond space and filtration. Most garden ponds are undersized for the fish kept in them. Inadequate filtration causes ammonia toxicity that slowly kills fish. Predation from herons is a common welfare problem. Winter management requires understanding koi dormancy needs.

What You Can Do

Provide at minimum 1000 gallons per koi with robust biological filtration
Protect ponds from heron predation using appropriate deterrents
Learn koi-specific winter management before establishing an outdoor pond
Never release koi into natural waterways where they become invasive