The final destination of the vast majority of ornamental fish are the closed environments of either an aquarium or domestic pond.
The "Pet Fish Belong..." poster was produced by OATA a number of years ago to serve as a reminder to the public not to release ornamental fish of any sort to the wild.

Section 14 of The Wildlife and Countryside Act, 1981 makes it an offence for any person to release or allow escape to the wild any animal which is a kind not ordinarily resident and is not a regular visitor to Great Britain in the wild state. These provisions apply equally to amphibians and reptiles. This Act requires that all reasonable care and due diligence is taken to avoid animals escaping to the wild.

Section 30 of the Salmon and Freshwater Fisheries Act 1975 requires that the wirtten consent of the National Rivers Authority is obtained before fish or spawn of fish can be released into any inland water.

See also: invasive plants
See also: "Ornamental fish and plants....must never"