Can I put fish in a wildlife pond?

It is better not to put fish in a wildlife-first pond. Froglife says fish prey on frogspawn, tadpoles and newt larvae, and even small fish compete with tadpoles for food.

Fish also change the water. Freshwater Habitats Trust lists fish food and waste as nutrient inputs, says fish disturb bottom sediment, and notes that they eat zooplankton that would otherwise graze algae. A pond designed around fish therefore needs different management, usually including appropriately sized filtration.

If you want both, create a separate fish pond and wildlife pond. That comparison is in how a wildlife pond differs from a fish pond. That avoids trying to make one small body of water serve conflicting aims. Do not release unwanted fish into the wild. GOV.UK guidance explains that releasing or allowing certain animals to escape into the wild can be an offence, and even a private pond can be relevant if there is no effective barrier to escape.

Decide the pond's priority

Write down whether the aim is breeding amphibians and varied invertebrates, or keeping fish. For wildlife, keep the water fish-free and provide shallow planted cover. For fish, plan the volume, filtration, pump, safe electrics and long-term care before buying livestock. If you inherit a mixed pond, do not move fish into a natural water body. Ask a reputable aquatic shop or rehoming organisation about lawful options, and avoid moving pond water or plants with them because that can spread disease and invasive fragments.

Keep a record of any fish species already present before seeking advice.

Sources

• Froglife: creating or improving ponds — accessed 14 November 2026.
• Freshwater Habitats Trust: frequently asked questions — accessed 14 November 2026.
• GOV.UK: section 14 guidance — accessed 14 November 2026.

More from Pond Setup Guide

Build a fish-free habitat with the wildlife pond guide. For a separate fish pond, start with filter sizing. Zooplankton is defined in the pond glossary.