Marine Mammal Rehabilitation
The purpose of marine mammal rehabilitation is to provide compassionate care for sick or injured marine mammals and to improve their chances of survival and being returned to the wild.
The primary goal of rehabilitation is to return live stranded animals to the wild once they are healthy. There are a number of authorized marine mammal rehabilitation facilities to care for species under our jurisdiction: pinnipeds (seals, fur seals, and sea lions) and cetaceans (whales, dolphins, and porpoises). Marine mammal rehabilitation facilities are highly variable in terms of their location, design, and amenities, such as an onsite hospital or research laboratory. They also vary in their capacity to treat different species, ages, and number of individuals. All marine mammal rehabilitation facilities must meet minimum standards as set forth in the NMFS Standards for Rehabilitation Facilities.
Rehabilitation facilities vary in many ways:
- Some are extensive and have permanent pools, whereas others use temporary pools when needed
- Some are designed for short-term holding (less than 96 hours) and primarily focus on the immediate stabilization and assessment of sick and injured animals
- Some provide longer term care, where animals can recover from illness and injuries before returning to the wild
Each rehabilitation facility has a maximum capacity (number of animals per pool or onsite at any one time) that should not be exceeded. During large-scale emergencies, such as mass strandings, oil spills, and Unusual Mortality Events, some facilities may increase their capacity. They can add temporary pools or holding pens, as well as volunteers or staff. Temporary facilities, not associated with permanent facilities, may also be set up to meet the short-term need.
Rehabilitation Considerations
Rehabilitation can be challenging and does not guarantee the short- or long-term survival of the individual animal. The decision to rehabilitate a live-stranded marine mammal can be complex and depends on multiple factors, such as:
- Available space at an authorized facility
- Available staff, resources, expertise, and funding
- Conservation priority (e.g., rehabilitation of an endangered species may take priority over abundant species)
- Distance between stranding location and rehabilitation facility, including transportation options
- How well the species does in a rehabilitation setting
- Likelihood of survival and release
- Long-term care options, if the animal is or may be deemed non-releasable
- Sex and age (adults require larger spaces than pups or calves)
- Social requirements (individuals of the same species may fight when placed together while other animals do better in social groups)
In the United States, many marine mammal rehabilitation facilities are equipped to handle pinnipeds since the animals are relatively small and live partially on land. Most facilities are designed to hold smaller and younger pinnipeds. Some cannot accommodate adult pinnipeds due to their size. Since cetaceans live entirely in the water and are more complex to care for than pinnipeds, fewer facilities nationwide can accommodate them. None are specifically designed to provide care for adult large whales (baleen and sperm whales).
Euthanasia may be considered as a last resort, if:
- A live-stranded animal is not a good rehabilitation candidate
- The animal is not likely to survive in the wild on its own
- Placement at a permanent care facility is not a viable option
Euthanasia is conducted in a humane, respectful, and efficient procedure by experienced and qualified personnel in accordance with nationally approved veterinary procedures.
Authorized Rehabilitation Facilities
Authorized Stranding Network organizations conduct rehabilitation of wild marine mammals under conditions outlined in the Marine Mammal Protection Act. Facilities are regularly inspected. They must meet minimum facility, husbandry, and veterinary standards, and maintain all applicable authorizations and state and local permits. Authorization to rehabilitate threatened or endangered species by the Stranding Network is currently provided under a permit issued to the NOAA Fisheries Marine Mammal Health and Stranding Response Program.
Specialized Care and Treatment
Rehabilitation activities vary depending on the context of the stranding event and the needs of the stranded animal. Patients with significant injuries or medical issues may require surgery; those in critical condition may need around-the-clock care. Other patients, such as those close to being released back into the wild, may only need minimal intervention or supportive care. The type of rehabilitation activities conducted at each rehabilitation facility also depend on staffing availability and expertise, as well as available funding, equipment, and other resources.
Learning from Rehabilitation
Stranded marine mammals may have very complex medical issues, and some die in care. Rehabilitation facilities conduct necropsies of these animals, as well as collect samples from all patients. NOAA Fisheries and our Stranding Network partners learn about the issues faced by that individual, which can aid treatment of other animals. For example, the care of Hawaiian monk seals, leading to successful treatment and release of this endangered species, is built largely upon decades of work with harbor seals, northern elephant seals, and California sea lions. Data collected from marine mammals in rehabilitation can also help identify and reduce threats to species in the wild.
Release of Rehabilitated Animals
NOAA Fisheries' release standards require that a marine mammal in rehabilitation be released back to the wild within 6 months unless:
- An attending veterinarian determines the release is unlikely to be successful due to the physical condition and behavior of the animal
- More time is needed for assessment and medical treatment
- The release might adversely affect wild populations
Prior to release in the wild, marine mammals must be marked or tagged to monitor their survival or identify them in the future, unless they have distinct natural markings. Scientists use tags or markings to evaluate rehabilitation success and to recognize individuals to monitor their growth, development, and behavior. Marking can be temporary, such as using bleach on a seal’s fur or attaching a plastic tag to a dolphin’s dorsal fin. More permanent marking methods include making a notch on a dolphin’s fin, inserting a scannable microchip, or freeze branding. NOAA Fisheries and our partners also use radio or satellite tracking tags to temporarily assess the movement and survival of an animal post-release.
Rehabilitated marine mammals are released under conditions that maximize the likelihood for their survival. For example, they are released within their home range or with another individual of the same species when possible. These conditions vary with species, age, and sex of the individual.
Non-Releasable Animals
Teams assess rescued marine mammals to determine whether they have the potential to be released back to the wild. This assessment is done as early as possible during the rehabilitation period. The animal’s rehabilitation care team makes a recommendation to NOAA on the releasability of the animal. The NOAA Fisheries Regional Administrator considers the recommendation and available developmental, behavioral, and medical records to make a final determination (i.e., releasable or non-releasable). Occasionally, a rehabilitated marine mammal might be deemed non-releasable due to age, behavioral, ecological, and/or medical concerns that make them unlikely to survive in the wild. Examples include:
- Orphaned animals that need maternal care or socialization
- Blind or deaf animals
- Animals with chronic medical conditions requiring continued care
The Marine Mammal Health and Stranding Response Program and NOAA Fisheries' Protected Resources Permits and Conservation Division work with marine mammal public display and research facilities to place non-releasable animals in permanent managed care for the individual animal’s continued welfare. These animals are a small proportion of all marine mammals brought into rehabilitation, although the percentage varies by species.
Funding for Marine Mammal Rehabilitation
Many rehabilitation facilities, most of which are non-profit organizations, rely on donations from the public, the support of volunteers, and in-kind donations. Some costs associated with response and rehabilitation during an Unusual Mortality Event may be reimbursed through the UME Contingency Fund. The competitive John H. Prescott Marine Mammal Rescue Assistance Grant Program is also available to help supplement marine mammal stranding response and rehabilitation costs.