Why do whales beach themselves in New Zealand?

Whales and Dolphins Beaching Explained

Whale and dolphin strandings are a common occurrence along New Zealand’s coastline, with several hundred animals stranding each year. These strandings can be distressing for both the animals and the people who come across them, and it is important to understand the causes and how to respond to them.

Causes of Strandings

There are many potential causes of whale and dolphin strandings, and in many cases, the reason is not fully understood. Some possible causes include:

  • Illness or injury: Whales and dolphins may strand due to a health issue, such as an infection or injury. These animals may have a compromised immune system, making them more vulnerable to strandings.
  • Environmental factors: Natural phenomena such as storms, earthquakes, or changes in water temperature and currents can disorientate whales and dolphins and lead them to strand.
  • Human activity: Anthropogenic activities, such as military sonar, oil and gas exploration, and commercial shipping, can disrupt the whales and dolphins’ normal behaviors and cause them to strand.
  • Genetic predisposition: Some species may have a genetic predisposition to strand more frequently than others.

What to do when finding a stranded whale or dolphin?

In addition to understanding the causes of whale and dolphin strandings and how to prevent them, it is also important to know how individuals can help when a stranding occurs.

If you come across a stranded whale or dolphin, it is important to report it to the authorities immediately. The Department of Conservation (DOC) and the Ministry for Primary Industries (MPI) are the two main organizations responsible for responding to strandings in New Zealand. They can be contacted at their emergency hotline number: 0800 DOC HOT (0800 362 468).

When reporting a stranding, it is important to provide the following information:

  • The location of the stranding (GPS coordinates if possible)
  • A description of the animal (species, size, condition)
  • The number of animals involved
  • Any visible injuries or abnormalities
  • The tide and weather conditions at the time of the stranding

When it comes to the first response protocol for a stranded cetacean, it is important to remember that the first priority is always the safety of yourself and others. It is not advisable to approach or touch a stranded cetacean as they can be distressed and may become aggressive. Cetaceans can also carry diseases that can be transmitted to humans.

Once you have reported the stranding, it is best to wait for the authorities to arrive and follow their instructions. If the animal is still alive, the authorities will assess its condition and determine the appropriate course of action, which may include refloating the animal, monitoring its health, or humanely euthanizing it if necessary.

If the animal is deceased, it is important not to disturb the carcass as it can provide valuable information to researchers. In this case, the authorities will collect samples and perform a necropsy to determine the cause of death.

It is important to remember that the help of the public is crucial in responding to a stranding. By reporting the stranding immediately, providing accurate information, and following the instructions of the authorities, individuals can play a vital role in ensuring the welfare of these animals and contributing to our understanding of the causes of strandings.

To be more prepared to help at a stranding you can attend a Marine Mammal Medic Course  run by Project Jonah. Click here for a useful PDF summary of how to help with a stranded animal.

Preventing Strandings

Preventing strandings is essential to the conservation of these animals, and there are several things that can be done to reduce the likelihood of strandings:

  • Minimize human activities that may disrupt the whales and dolphins: This includes reducing the use of sonar and other loud underwater noise, minimizing the impact of commercial shipping, and avoiding oil and gas exploration in areas where marine mammals are known to congregate.
  • Monitor the health of the population: Regular monitoring of the population’s health can help to identify any potential health issues that may make the animals more susceptible to strandings.
  • Use of beach-casting nets: These are nets that are placed on the beach to help guide stranded animals back to sea.
  • Be aware of the tide and weather conditions: Be mindful of tide and weather conditions, and avoid any activities that may disrupt the natural behavior of marine mammals.

In conclusion, understanding the causes of whale and dolphin strandings and how to respond to them is crucial for the conservation of these animals. By reducing human activities that may cause strandings, monitoring the population’s health, and being aware of the tide and weather conditions, we can help to reduce the likelihood of strandings and ensure the survival of these magnificent creatures.

It’s important to remember that the prevention of strandings is a collective effort and everyone can play a role by being responsible and respectful when interacting with marine life and by supporting conservation efforts.

References:

  1. NOAA Fisheries. (n.d.). Marine Mammal Health and Strandings Protection Program – Strandings. Retrieved from https://www.fisheries.noaa.gov/topic/marine-mammal-health-and-strandings-protection-program-strandings
  2. Department of Conservation. (n.d.). New Zealand Marine Mammals: Strandings. Retrieved from https://www.doc.govt.nz/nature/native-animals/marine-mammals/strandings/
  3. Southall, B. L., Bowles, A. E., Ellison, W. T., Finneran, J. J., Gentry, R. L., Greene, C. R., … Tyack, P. L. (2007). Anthropogenic noise and the effects on marine mammals. Marine Pollution Bulletin, 54(3), 292–303. https://doi.org/10.1016/j.marpolbul.2006.11.012
  4. Rone, B. K., & O’Corry-Crowe, G. (2013). The Genetics of Marine Mammal Strandings. Journal of Heredity, 104(1), 1–11. https://doi.org/10.1093/jhered/ess104
  5. Southall, B. L., Bowles, A. E., Ellison, W. T., Finneran, J. J., Gentry, R. L., Greene, C. R., … Tyack, P. L. (2007). Anthropogenic noise and the effects on marine mammals. Marine Pollution Bulletin, 54(3), 292–303. https://doi.org/10.1016/j.marpolbul.2006.11.012
  6. Rowles, T., & Jepson, P. D. (2003). Monitoring the health of marine mammal populations. Marine Mammal Science, 19(4), 619–644. https://doi.org/10.1111/j.1748-7692.2003.tb01153.x
  7. Rone, B. K., & O’Corry-Crowe, G. (2013). The Genetics of Marine Mammal Strandings. Journal of Heredity, 104(1), 1–11. https://doi.org/10.1093/jhered/ess104