Science Advisory Report 2018/026

Advice on Criteria for the Release of Rehabilitated Marine Mammals

Summary

• In Canada, the keeping of marine mammals in captivity falls under provincial jurisdiction. However, the federal Department of Fisheries and Oceans Canada (DFO) is responsible for the protection, conservation and management of marine mammals, which includes authorizing capture for captivity and the transfer and release of rehabilitated marine mammals into the wild.
• Marine mammals considered for release should have a reasonable likelihood of surviving in the wild. As such they should be assessed to be in good health, and capable of feeding on their own prior to release.
• Marine mammals considered for release should not pose a risk to the wild population (e.g., carry exotic pathogens).
• The duration of rehabilitation of marine mammals should be kept to a minimum.  A prolonged stay may lead to habituation to humans, which could have negative consequences, either for the animal or for humans, following release. It could also increase the likelihood of disease transmission.
• Marine mammals born in captivity and held for public display should not be released to the wild. Marine mammals are also deemed “non-releasable” if they have been in captivity for more than 2 years.
• Cetacean calves and sea otter pups that are dependent on their mother at capture are considered not releasable. Because of the long dependency period for some otariid species, pups of these species should not be released into the wild unless it is thought that they have a reasonable probability of survival. Seals should be released within 6 months of capture.
• Marine mammals considered for release should be rehabilitated in an appropriate rehabilitation center (RC).
• The RC must not hold in the same facility marine mammals together with other species of marine animals that are not normally found in the region or with non-marine species because of the risk of transmission of new pathogens. If an institution maintains different facilities holding multiple species, strict quarantine measures must be in place to isolate these animals from each other.
• Some pathogens carried by marine mammals can cause disease in humans (zoonoses), and the reverse may also occur (anthroponoses). The chances of pathogen transmission must be minimized by using proper animal handling protocols for marine mammals being considered for release.
• Marine mammals should be released in areas and at a time where conspecifics, ideally those of the same population, are present.
• Post-release monitoring for survival and re-adaptation to the wild is recommended for all rehabilitated marine mammals, especially animals of threatened or endangered species.

This Science Advisory Report is from the April 26 and June 27, 2017 meeting on Standards for the Release of Captive Marine Mammals into the Wild. Additional publications from this meeting will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Schedule as they become available.

Complete document (PDF, 295 KB)

Accessibility Notice

This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.