TECHNIQUE

Refloatation of Stranded Whales & Dolphins (Wildlife Casualty Management)

Summary Information
Type of technique Health & Management / UK Wildlife Casualty Management / Techniques:
Synonyms and Keywords N.B. This information should be read in association with Wildlife Casualty Release which contains background information together with links to the Electronic Library and Organisations (UK Contacts). The related Species pages contain similar linkages.
Description This page has been prepared for the "UK Wildlife: First Aid and Care" Wildpro module, and is designed for the needs of the following species: Balaenoptera acutorostrata - Minke Whale, Delphinus delphis - Common dolphin, Globicephala melas - Long-finned pilot whale, Grampus griseus - Risso's dolphin, Lagenorhynchus acutus - Atlantic white-sided dolphin, Lagenorhynchus albirostris - White-beaked dolphin,  Orcinus orca - Killer whale, Phocoena phocoena - Common porpoise, Physeter macrocephalus - Sperm whale, Stenella coeruleoalba - Striped dolphin, Tursiops truncatus - Bottle-nosed dolphin.

These species are within the families Balaenopteridae, Delphinidae, Phocoenidae, Physeteridae

  • Refloatation (immediate release) is the goal in most cases of live cetacean strandings if the animal's condition allows.
  • Experienced personnel and suitable equipment are required for refloatation of cetaceans. Any person wishing to be involved in the rescue of stranded cetaceans should seek appropriate training, such as the courses run by British Divers Marine Life Rescue.

Pre-release:

  • Measures should be taken to keep the cetacean calm, minimise stress to the animal and keep it as comfortable as possible. This includes providing protection from sun, heat and drying winds.
  • Contact with an individual human talking quietly and stroking the cetacean gently frequently helps to keep the animal calm and reduce stress. In a group stranding it may be beneficial to appoint one person for each animal.
  • Loud noises and excess visual stimulation in the area around the cetacean should be minimised. This includes avoiding loud voices, barking dogs, flash photography and sudden movements.
  • The cetacean should be supported in an upright position with trenches dug under the pectoral fins.
  • The animal should be covered with wet towels/sheets (seaweed may be used if cloths are unavailable) and be kept moist and cool by repeated spraying or dowsing of the whole body with water. Wetting the rear half of the animal may be particularly important as the tail stock appears to act as an important site for heat loss. Very cold water/ice must not be used on the flukes or fins.
  • Care should be taken to keep the blowhole clear and to prevent water or sand entering it. It must never be covered, but the margins may be protected by being smeared with lubricating jelly or zinc oxide cream.
  • The cetacean should be protected against the sun by erecting a sunscreen or if this is not possible and the animal is of a size allowing it to be moved, by moving the animal into shade. See: Lifting and Moving of Stranded Cetaceans.
  • Windbreaks should be erected in cold windy weather, particularly for emaciated animals and neonates. In windy weather, mineral oil such as liquid paraffin, or vegetable oil, rather than water, may be used to soak the sheets over the cetacean.
  • (D14, D23, D44)

Release assessment/criteria:

  • Examination by a veterinarian should be carried out before release if possible although waiting for a vet to arrive should not delay the start of refloatation.(D14)

  • Good candidates for refloating are adults and juveniles of pelagic species (neonates only if accompanied by their mother), with good or moderate body condition, no clinical signs of significant disease and no severe traumatic injuries.(D42)
  • Animals are not suitable for refloatation (release) if they are emaciated, have significant traumatic injuries or signs of severe disease, neonates without their mother, or if suitable equipment for e.g. transportation, if required, is not available.(D14)

Selecting a release site:

  • Refloatation normally takes place from the place of stranding.
  • Animals may be transported to a different site if the stranding site is unsuitable for refloatation and the animal is of a size, and equipment is available, which allows transport to a more suitable location.(D14)

Timing of release:

  • As soon as possible.
  • For large animals which cannot be carried, it is necessary to wait for the tide to come in in order to start refloatation.

Type of release:

Refloatation of individual cetaceans:

  • The animal may be moved into the water using a tarpaulin, stretcher or (for e.g. whales the size of pilot whales) pontoons.
  • For large animals which cannot be carried, it is necessary to wait for the tide to come in.
  • The animal is physically supported in waist-deep water using hands, towels as slings under the animal, or pontoons.
  • Physical support may be required for minutes or several hours following refloatation until the animal is able to support itself in the water.
  • Rocking the animal gently from side to side may assist it in regaining its equilibrium, relieve muscle stiffness and restore blood circulation.
  • Rocking may be discontinued only when the animal swims in an upright position without support.
  • Care must be taken to keep in waist to armpit depth water while supporting the animal.
  • Several hours may be required before signs of disorientation, listing and inability to swim subside.
  • Abnormal behavioural signs for animals being supported in the water include incoordinated movements (twitching, trembling) and pronounced flexion of the body.
  • Once the animal appears able to support itself upright it may be moved into deeper water periodically to see whether it can swim; if it is not yet able to swim it is moved back into shallow water for a while.
  • Once the animal is able to swim it is released and guided seawards gently; surf boards, divers and small boats may be useful for this.
  • Alternatively an animal may be moved further out to sea for future release (using boats and e.g. pontoons, as required), particularly if the animal had stranded in an estuary, harbour or narrow-necked bay.
  • (D14, D23, P24.335.w6)

For mass strandings:

  • Animals which are unlikely to survive must be identified and euthanased.
  • All animals suitable for refloating should be brought into shallow water and prepared for release.
  • The largest female may be identified and refloated first as she may call the others back out.
  • Alternatively the largest female and one or two others, for example calves, may be towed out to sea using pontoons strapped to the sides of boats.
  • These individuals are then turned to face the shore while the remaining animals in shallow water are turned to face the sea; it is hoped that the acoustic signals from the key animals in deeper water will encourage the remaining animals to move out to sea.
  • (D14, P24.335.w2, P24.335.w6)

Further detailed descriptions of refloatation of both individuals and groups of cetaceans are given in D14 - Marine Mammal Medic Handbook (BDMLR) (Full text incorporated) and D23 - Stranded whales, dolphins and porpoises a first aid guide (RSPCA) (Full text incorporated).

Appropriate Use (?)
  • Individuals of pelagic species (rarely of coastal species).
  • Adult or juvenile animals (neonates only if the mother is present).
  • Animals should be in good or moderate body condition (nutritional status).
  • Animals which do not show clinical signs of significant disease or severe traumatic injuries.
  • (D42)
  • The individual animal must, at the the time of release, be healthy, have a reasonable level of fitness and be able to fend for itself in the wild.
Notes
  • Release should preferably take place during a period of fine weather.
  • Animals may be transported to a different site if the stranding site is unsuitable for refloatation and the animal is of a size, and equipment is available,  which allows transport to a more suitable location.(D14)
  • Hours to days may be required for refloatation.
  • Examination by a veterinarian should be carried out before release if possible although waiting for a vet to arrive should not delay the start of refloatation. (D14)
  • Photographs of the animal's dorsal fin and back should be taken prior to release for identification purposes.(D14, D23)
  • A piece of biodegradable ribbon (e.g. natural wool) may be tied loosely around the tail stock to allow temporary identification of released animals.(D14, D23)
  • Coloured skiers' sun block may be used on the dorsal fin to create a temporary identification mark.(D23)
Complications/ Limitations / Risk
  • Animals which re-strand following a controlled refloat have a poor prognosis.(D14)
  • Refloatation of individuals of coastal species such as common porpoises (Phocoena phocoena - Common porpoise) are often unsuccessful.
  • Success of refloatation of animals in mass strandings, in which most animals are healthy at the time of stranding, may be greater than for refloatation of individual animals.
  • Animals are not suitable for refloatation (release) if they are emaciated, have significant traumatic injuries or signs of severe disease, neonates without their mother, or if suitable equipment for e.g. transportation, if required, are not available.
  • The time of transportation to a more suitable location for refloatation must be limited. (D14)
  • Potential hazards with staff working in or near the sea include drowning, hypothermia and physical injury. 
  • Released animals may be at risk of contracting disease if there is an ongoing disease problem in the wild population at the time of release.
  • The wild population may be at risk from novel pathogens (disease agents) carried by a rehabilitated animal. These pathogens may pose the greatest threat to free-ranging populations if the animal is to be released at a site distant from its original location therefore increasing the likelihood of spread of disease. It is important to remember that the casualty wild animal may have acquired disease from domestic animals, other wildlife casualties or humans whilst in captivity. 
Equipment / Chemicals required and Suppliers
  • Refloatation equipment ranging from tarpaulins to pontoons may be required, as well as suitable clothing (dry suits or wet suits) for personnel, small boats for shepherding animals back out to sea etc. Further information of equipment is included in D14 (Available in the Electronic Library: Marine Mammal Medics Handbook (BDMLR)).
Expertise level / Ease of Use
  • Experienced personnel and suitable equipment are required for refloatation of cetaceans. Any person wishing to be involved in the rescue of stranded cetaceans should seek appropriate training, such as the courses run by British Divers Marine Life Rescue.
Cost/ Availability
  • Refloatation and release may involve a considerable time investment in time and equipment.
  • Costs of appropriate health screening.
Legal and Ethical Considerations
  • The potential risks to the individual being released and to the wild population into which it is being released (also to domestic animals) must be considered before release is undertaken.
  • The potential risk to humans and pets from habituated/tame individuals must be considered.
  • An offence may be committed under Section 1 of the Abandonment of Animals Act 1960 if a released rehabilitated animal does not have a reasonable chance of survival (i.e. a chance similar to its non-rehabilitated peers).
    • This may include release at an unsuitable site, in the wrong territory, unfit, not having learned to hunt, at the wrong time of year etc. 
  • (J35.147.w1, B156.21.w21, B223, W5.Jan01).
  • Sea shores are potentially hazardous environments. The risks to human health and safety must be remembered: these include sharp rocks, water and the external environment, which may lead to physical injury, drowning, hypothermia or (less commonly in the UK) hyperthermia/sunstroke. All personnel who may work in such conditions must be given adequate training to ensure that they are aware of the risks and know how to minimise these risks.
  • Health and Safety at Work, etc. Act 1974 applies to protect any employees of a wildlife hospital, as well as volunteers at the hospital and visitors. Appropriate safety procedures must be provided to take into account any special risks involved with persons working with non-domesticated species (J35.147.w1, B142.4.w4, B156.21.w21)
Author Debra Bourne
Referee Becki Lawson and Suzanne Boardman
References

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