WDC position on the welfare of stranded whales and dolphins

Whales and dolphins will suffer physically as a result of being out of the water for prolonged periods of time, an experience which is undoubtedly psychologically stressful for these marine mammals. Welfare consideration for the individual whale or dolphin in decision-making is paramount.

Whales and dolphins are often very social mammals, some exhibiting high levels of cognition. Many live in complex and little-known communities, are capable of experiencing a range of emotions and have been demonstrated to be sentient and sapient beings.

Animal welfare is a multi-disciplinary scientific field. The wellbeing of an individual has many different aspects and is defined by both physical and psychological states. Major concerns for animal welfare arise from handling and killing practices with low welfare potential i.e. those that fail to meet the behavioural and physical needs of the individual and thereby have the potential to cause pain or suffering. This includes human intervention during a stranding.

Guidance in decision-making

Options for dealing with stranded marine mammals include no intervention, re-floatation, rehabilitation or euthanasia. To this end, WDC recommends referring to the guidance for re-floatation and other strandings responses available (RSPCA, 1998; ACCOBAMS, 2004; BDMLR, 2006). Welfare consideration for the individual whale or dolphin in decision-making is paramount. The quality of existing science and veterinary evidence are also important. Whales and dolphins will suffer physically as a result of being out of the water for prolonged periods of time, an experience which is undoubtedly psychologically stressful for these marine mammals. In addition, a stranded whale or dolphin could be suffering from an underlying, undiagnosed medical condition that could also have contributed to the stranding event.

Some examination of factors influencing successful release and success rates of post-intervention survival of whales and dolphins that have received aid from humans through the various methods of intervention have been undertaken in the United States (Zagzebski et al., 2006; Wells et al., 2012). Further, there are legal considerations. A review of European conventions and agreements demonstrated considerable variation, but all stated objections to prolonged captivity under ASCOBANS, ACCOBAMS, the WSSA, the Bern Convention and the Habitats Directive, presupposing that the purported repatriation does not compromise the wider environment (Trouwborst et al., 2012).

WDC recommends that everything be done to ensure that stranded cetaceans are swiftly evaluated and treated on site for release back into the wild, including vagrant individuals who are far from their home range, or those with flesh wounds, that are likely to heal (Bossley, pers. comm.). In cases where beach release is not possible, cetaceans should be humanely euthanised. This view is based on our evaluation of the available evidence.


WDC believes that euthanasia should only be conducted under the direction of a trained veterinarian and in those extreme circumstances where: lack of intervention would cause considerable and prolonged suffering; or where the animal is obviously already in pain with little to no chance of long-term survival, including in cases where there is a dependant calf but a lactating female cannot be located.

Euthanasia techniques for large whales should continue to be developed under the direction of a trained veterinarian, and in consultation with others with necessary expertise in the relevant techniques and large whale biology, to ensure that it is as humane as possible. Where humane euthanasia cannot be guaranteed, a natural death should be considered.

Captive rehabilitation

WDC does not normally endorse bringing whales and dolphins into captivity for rehabilitation purposes and our concerns are laid out in a separate briefing. It has been well-established in veterinary medicine that even with excellent care, animals that suffer stranding, examination, diagnostic data collection, transport and environmental change in the rehabilitation facility may still fail to thrive due to stress (Wells et al., 2012).

Existing evidence demonstrates that captive rehabilitation does not have a high success rate. Survival and release of rehabilitated odontocetes in California was low (five out of 68 individuals, or 7.3%) over the 25 years of data reviewed, with most mortality occurring within 24 hours of stranding (Zagzebski et al., 2006). Over the same time period, a separate US study demonstrated that in most cases, if release failed, the failure (for whatever reason) usually occurred within the first six weeks. During the first six weeks post release, 57% of cases died or disappeared (Wells et al., 2012). The focus of this review was on the fates of small cetaceans released after rehabilitation or at-sea interventions, rather than on the success of cetacean rehabilitation in general (Wells et al., 2012).

Despite growing evidence for a significant number of deaths after rehabilitation and subsequent release, there are instances where captive rehabilitated odontocetes have been released successfully. The review detailed above found that most animals that survived for at least six to nine weeks were detected for months beyond this period (Wells et al., 2012). A European facility has a success rate of 39% for rehabilitation of harbour porpoises, an increase from between 10 – 20% from 1967 to 1997 (Harderwijk, 2013). It is standard practice in some countries to rehabilitate (Whaley and Borkowski, 2009) and as a result, a series of recommendations have been made to improve future decision making surrounding rehabilitation in the US (Wells et al., 2012; Moore et al., 2007).

As a result of current practices, WDC maintains that any rescue effort that includes rehabilitation should only occur for a temporary and pre-determined (short) period of time, under constant veterinary advice and supervision, and only in cases where the animal has a high likelihood of treatment and swift release back into the wild.

However, WDC maintains that there are too many unknowns with captive rehabilitation to be confident that this is a viable and humane alternative to recommend for a dolphin in extremis. We will continue to advocate the release of all captive whales and dolphins, and lobby for the best care for captive individuals until such a time.

Other ethical considerations

Tagging, biopsy and other experimentation WDC strives to ensure that benign research methods are promoted as a guiding principle. WDC takes the use of invasive research techniques very seriously and believes that all possible alternatives should be fully explored before deciding on the use of an invasive method. However, WDC acknowledges that there may be extenuating circumstances where invasive methods may be considered as a part of a solution, but only where they are likely to result in long-term and significant conservation benefit. In such a case, strategic long-term monitoring and reporting of the impacts of any invasive research, as well as the successfulness of the technique, is essential. In addition to potentially increasing stress and causing additional pain for a stranded whale or dolphin, the potential for infection from invasive activities must be taken into consideration. These should be weighed against any potential benefit and decisions undertaken with an experienced veterinarian.

Where re-floatation is planned, tagging or biopsy should never compromise the swiftness of the rescue response to the individual whale or dolphin and should also only be undertaken by an experienced individual under veterinary supervision. The impacts of non-invasive tests, such as Auditory Brainstem Response (ABR), should be carefully considered in relation to the potential for negative impacts on an individual already in extremis, versus the potential welfare benefits to the individuals, to other individuals and in relation to wider conservation questions. Such ethical judgements should be made on an individual case by case basis and subject to independent ethical review and the appropriate permitting procedures. Where re-floatation is planned, this should not be delayed due to any such procedures. Identification of re-floated individuals is useful where there is a high potential for re-stranding (for example, re-floatation of a pod of pilot whales). Biodegradable tape (tied around the tail-stock) can be useful in the short-term for recognising previously stranded animals and to assist with subsequent identification at sea.


ACCOBAMS. 2004. Guidelines for the Development of National Networks of Cetacean Strandings Monitoring, available here: http://www.rspca.org/sites/default/files/doc_cetacean/stranding.pdf

BDMLR. 2006. Marine Mammal Medic Handbook. www.bdmlr.org.uk

Harderwijk. 2013. SOS Dolfijn - Rescue & Rehabilitation of Cetaceans in the Netherlands website. http://www.eaam.org/index.php?option=com_content&view=article&id=90:sos-...

Moore, M., Early, G., Touhey, K., Barco, S., Gulland, F. and Wells, R. 2007. Rehabilitation and Release of Marine Mammals in the United States: risks and benefits. Marine Mammal Science, 23, 731-750.

RSPCA. 1998. Stranded Whales and Dolphins A First-aid field guide, available here: http://wildpro.twycrosszoo.org/S/00Ref/miscellaneouscontents/rspca-stran...

Trouwborst, A., Caddell, R. and Couzens, E. 2012. To Free or Not to Free? State Obligations and the Rescue and Release of Marine Mammals: A Case Study of ‘Morgan the Orca’. Transnational Environmental Law, 1-28.

Wells, R.S., Fauquier, D.A., Gulland, F.M.D. and DiGiovanni, R.A. 2012. Evaluating postintervention survival of free-ranging odontocete cetaceans. Marine Mammal Science.

Whaley and Borkowski. 2009. Marine mammal stranding response, rehabilitation and release. Available online at: http://www.nmfs.noaa.gov/pr/pdfs/health/release_criteria.pdf

Zagzebski, K.A., Gulland, F.M.D., Haulena, M., Lander, M.E., Greig, D.J., Gage, L.J., Hanson, M.B., Yochem, P.K. and Stewart, B.S. 2006. Twenty-Five Years of Rehabilitation of Odontocetes Stranded in Central and Northern California, 1977 to 2002. Aquatic Mammals, 32, 334-345.