Stranding events (also known as beaching) involving cetaceans (whales, dolphins, and porpoises) have been documented since the 4th century. Originally, people considered stranded cetaceans a gift from the gods, providing food and other resources. However, today’s society has mostly shifted its vision of strandings to animals in need of human help. Most stranding events will involve single animals, but mass strandings involving up to hundreds of animals can occur in some locations. These large mass stranding events often occur regularly in the same hot spots globally, including Cape Cod in the USA, Tasmania in Australia, and Farewell Spit in New Zealand. In this post, we explain what you can do if you come across beached whales or dolphins.
Disclaimer: we both have first-hand experience at live stranding events in New Zealand.
Different types of stranding events
Four primary types of strandings exist, and they vary in their likely causation and the characteristics of the animals involved.
One animal or a mother-calf pair strand. This is the most common type of stranding. These animals often have underlying health issues, such as illness or poor nutritional condition. However, they may also be related to human activities like harassment or entanglement.
Two or more individuals strand in the same area at the same time. These events are typically different to single strandings, with many individuals appearing outwardly healthy. However, animals can become jeopardized due to the stranding event itself (e.g., internal organ damage due to their body weight on land, scavenger damage, trauma, and sunburn). These mass strandings often involve species known to have strong social bonds, like pilot whales.
Unusual mortality events
These also involve large numbers of individuals, but these animals strand over a much wider area and time scale. This type of stranding event is generally linked to disease, although oil spills have also been implicated. Human activities such as naval sonar have also caused some unusual mortality stranding events, particularly in beaked whales.
While also considered stranding events, these individuals do not usually beach themselves on the shore. This occurs when an animal is found in an area considered unusual for the species. Recent events include the beluga whale reported in the Thames River, London or the Walrus ‘Wally’ observed around Ireland, the UK, and mainland southern Europe. In some cases, these individuals may be healthy and simply lost, but they may become compromised due to the inappropriate habitat.
The impact of stranding on a cetacean
So, stranded animals may be ill or injured in some cases, while in others, they may appear healthy. However, the stranding event itself can cause significant compromise due to physiological stressors. Because they evolved to live in water, cetaceans cannot support their body weight on land; therefore, when stranded, their weight can crush their organs. Due to their thermoregulatory system adapted to being in the water, they can also quickly overheat on land. Their skin is also not adapted to be dry and becomes desiccated and easily damaged when not submerged. In sunny conditions, thermally induced sunburn can also occur, causing skin blistering.
The experts’ stranding response
Today’s response to strandings often focus on trying to ‘save’ animals by refloating them. However, depending on the specific situation (i.e., external and internal injuries, time stranded, illness/disease status), refloating an animal could extend its suffering until its inevitable death rather than saving its life. In some cases, animals may have significant injuries or illnesses or become severely weakened due to stranding and are unlikely to survive even if rescuers refloat them. In these cases, the use of euthanasia to humanely end suffering, or the provision of palliative care until natural death, offer better options from an animal welfare perspective. Therefore, before refloating an animal, cetacean stranding experts or veterinarians should undertake a comprehensive animal assessment. They should evaluate both health and welfare to determine that, a) no prolonged suffering will occur, and b) to ensure that survival is likely if refloated.
What you can do as a citizen if you come across a stranded cetacean
To reduce additional welfare compromise and increase an animal’s chance of survival, you may undertake several procedures as part of first aid in stranding response. But it is critical to know how to act. However good their intentions, untrained people can worsen an animal’s situation through stress and injury, and may put themselves and others at risk of injury and exposure to pathogens. Here we provide a simple overview of what to do and not to do if you find a stranded cetacean.
- CALL: Phone your local stranding network, environment agency or emergency services. You will need to tell them the location, number of animals and offer a physical description, including visible external injuries. Take photographs if possible and send these to them. You can find information on your local stranding network here.
- CALM: Remain calm and quiet, keep people and dogs away from the animal(s). Undertake any procedures outlined gently and slowly, and only at the direction of the stranding experts.
- COOL: While waiting for experts, you can begin to keep the animals cool by gently pouring water over their bodies. You mustn’t pour water into the blowhole, as this is how they breathe.
- SHADE: While waiting for experts, you can cover the animal in thin wet sheets or similar, or if none are available, you can use a thin covering of wet seaweed. You must place NO cover over the head and blowhole, dorsal fin (on back) and tail. Try to avoid covering the pectoral flippers (each side of the body) if possible.
- COMFORTABLE: If the animal is a smaller cetacean lying on its side, and the stranding experts direct you to do so, you can gently roll the animal into an upright position on its belly. You must ensure the pectoral flippers (each side of the body) are tucked close against the body before beginning this rolling.
- COMFORTABLE: When an animal is upright, carefully dig shallow trenches under the pectoral flippers (each side of the body) so that these can hang in a natural position. However, be aware that sand may build up over the top of these as you pour water on the animal.
- TOUCH the animal unnecessarily. Stranded cetaceans may be carrying pathogens. You should avoid exposure by not touching them.
- MOVE, push, pull/drag or roll an animal to get it back into the sea. It must be assessed by a stranding expert or veterinarian before it can be refloated. Moving an animal in an inappropriate way can cause significant internal damage or even death.
- PULL or push on any fins or flippers. They are very delicate and moving them inappropriately can cause severe damage.
- COVER the head, blowhole, fins or tail.
- STAND close to the tail. The animal may suddenly thrash and can easily hit you. Humans have been seriously injured in this manner.
- CROWD close to the blowhole or head. The animal breathes from the blowhole, being close means you may inhale as they breathe out, taking in pathogens they may be carrying.
- INSERT anything into the blowhole or mouth, do not try to feed or make an animal drink.
Whale Scientists team here! We hope you found this post helpful. We would like to warmly thank Katharina and Rebecca for putting together this post. You can visit their page here.
If you are interested in stranding events, you can read our other posts here or check out our post on beached beaked whales:
Rebecca M. Boys is a PhD student in the Cetacean Ecology Research Group at Massey University, Auckland, New Zealand. Her research investigates the application of welfare science to cetacean strandings to help inform decision-making. Her previous research at the Institute of Marine Science in the Azores (IMAR and MARE) included applying mark-recapture models to estimate demographic parameters of cetacean populations.
Katharina J. Peters is a postdoctoral fellow at the University of Zurich, Switzerland, and a research associate at Massey University, Auckland, New Zealand. Her research interests lie at the interface of animal behavior, population ecology and evolutionary biology and how to apply this information to better manage the conservation of wild populations and their associated environments. Her current projects focus on reproductive success on bottlenose dolphins in Shark Bay, Australia, and on the foraging ecology and distribution of odontocetes in New Zealand waters.