By Clare Moore, Community Ranger.
One of New Zealand’s largest ever pilot whale strandings took place last month at Farewell Spit.
About 200 pilot whales died but DOC, Project Jonah, tangata whenua and many volunteers worked tirelessly to rescue what animals they could over three days. It is believed that more than 400 whales were successfully refloated.
Why do whales strand?
Whale and dolphin strandings are a natural phenomenon which have been occurring for millennia, but are still not fully understood.
There are many theories, but in most cases the cause is unknown and is unlikely to be due to any one factor alone.
Possibly the leader of the pod is sick or disoriented and the pod simply follows the leader. Another cause may be a young whale becoming stranded by accident and the rest of the pod try to come to the rescue.
They may run into problems when the shoreline is gently sloping; sand and mud absorb the sonar signals they use for navigation, giving a false indication of how deep the water is.
Other possible factors include navigational error, unusual geographic features and extreme weather events.
Hot spot for strandings
The largest mass stranding on record in New Zealand was in 1918 when 1000 whales stranded on the Chatham Islands.
New Zealand is a hot spot for marine mammal strandings. Since 1840, more than 5000 strandings of whales and dolphins have been recorded around the New Zealand coast.
Strandings occur all year round and usually involve just one or two animals. Mass strandings on the other hand, involve more than two animals but may involve hundreds of animals.
New Zealand is at the forefront of whale rescue work. DOC manages whale strandings and rescues, with the help of local communities, volunteers, and organisations like Project Jonah.
DOC responds to an average of 85 stranding incidents per year, usually of single animals.
Many Māori view whales and dolphins as taonga (treasured) species and will often be involved in stranding events ensuring correct tikanga (Māori custom) is followed.
The most common species that strand alone are common dolphins, pygmy sperm whales, and beaked whales. The majority of mass strandings are long-finned pilot whales.
Even large whales such as sperm whales have been known to strand occasionally.
How you can help
Anyone can help out at a stranding event as long as they are physically able.
To be more prepared to help at a stranding you can attend a marine mammal medic course run by Project Jonah.
Those who have completed the course will be well equipped to help rescue stranded whales and dolphins, and can help direct untrained rescuers.
Being trained by Project Jonah means you will be more aware of the rescue process, including health and safety risks, which makes the process run more safely and smoothly.
Your efforts are much appreciated by DOC. Many whales are saved each year with the help of volunteers – every effort contributes towards their conservation.
This article first appeared in the Marlborough Express earlier this month.