A desperate rescue effort running against the time, hundreds of long-finned pilot whales (Globicephala melas) became stranded in Macquarie Harbor on Tasmania’s west coast.
More than 450 pilot whales were reported to have stranded in two places, within 10 km distance.
The stranding, one of the largest ever recorded globally, eclipses a previous national record of 320 set in Western Australia in 1996.
After some pilot whales have been rescued and floated back up, hope sinks because their behavior makes rescue efforts more difficult, many pilot whales re-strand themselves to be with their family. This event likely means, a number of generations of the local population will be lost forever.
The long-finned pilot whale is actually a large oceanic dolphin, although the name let us think about a whale. Reaching between four and six meters in length and weighing up to one ton, they are well adapted to deeper oceans where they hunt for various species of squid in depths of between 600 - 1.000 m, using echolocation to find their prey. Echolocation is a way of using sound to navigate in complete darkness.
What conditions drive them to shore and shallow waters, when they generally spend most of their lives offshore? Various theories suggest changes in electromagnetic fields that disorient them, or food shortages are to blame, or they may also be following a sick or distressed pod leader. And in some past cases, strandings were related back to active sonar from ships and naval sonar interrupting their echolocation.
It’s difficult to swim back out, once in the shallow. As these whales mostly navigate with echolocation it’s not possible for them to use sonar effectively in shallow waters and it’s extremely distressing for the whales, a lot like trying to find the exit in a dark room while hearing your relatives scream for help. The stress causes many deaths in the end or other causes are overheating from sun exposure and drowning if they can’t move their bodies up to breach the surface in shallow water.
Rescuers had managed to save 50 by late on Wednesday, and they were trying to help the remaining estimated 20 whales after 380 died. Tasmanian government officials said the rescue effort would continue "as long as there are live animals. While they're still alive and in water, there's still hope for them.”
In Macquarie Harbor, rescuers are using slings to tow the whales to deeper water, before releasing them. Other options include multiple people pushing them off the beach during high tide into deeper water. After all, time is of immense importance for success, and to stop more whales from stranding. The biggest obstacle rescuers face is the whales’ social bonding. Long-finned pilot whales are highly intelligent and live in strong social units. It’s important to realize the emotions and bonding between the whales. One well-documented example of their emotional depth is the pilot whale seen carrying its dead calf for many days.
Pilot whale pods have multiple sub-units, which can consist of friends as well as family and they don’t have to be genetically related. When they are in shallow bays social units get mixed up. This means individuals can become disconnected from their social units before the actual stranding occurs, causing stress and confusion prior to the beaching. But in the past, many stranded whales have been successfully released. Do you remember, in one of the largest mass strandings in New Zealand in 2017, volunteers helped about 100 whales refloat, and made a HUMAN CHAIN to try to stop them restranding…
Where there is great LOVE, miracles happen…
It breaks my heart when I think of the 380 pilot whales.
Rest in peace beautiful souls. We will never forget you...