| Cheryl Norrie |
Wellington (dpa) – The regular strandings of whales on New Zealand beaches are one of the saddest sights in nature, and rarely have a happy ending.
About 140 pilot whales died after a pod of nearly 200 stranded at Farewell Spit, a sandbar in the South Island Friday, in the biggest mass beaching in recent times.
Department of Conservation staff and volunteers helped to refloat 60 of the whales on Saturday evening’s high tide, and were hopeful that they would stay in deeper water and not re-strand, Golden Bay Conservation Services manager Andrew Lamason said Sunday.
Whale strandings are common at Farewell Spit, a 35-kilometre sandbar in the shape of a fish hook which arcs across the northern tip of the island, forming a trap.
More than 60 pilot whales stranded in the same area in January 2014, and nine were euthanised after they continued to re-strand in spite of efforts to return them to deeper water.
It is not known why the large pod of 198 whales became stranded last week. Lamason said they may have been hunting fish and had become caught in shallow water when the tide went out.
“There are huge schools of yellow-eyed mullet in the bay and they could be trying to catch those, but it is very, very shallow around the spit there, and when the tide drains out, it drains out for kilometres and kilometres.”
“Once they are enclosed there is a good chance that their echolocation is just not able to pick up where the shore is and where deeper water is and as the tide drains out, they are caught.”
Marine mammal conservation group Project Jonah’s general manager Daren Grover said pilot whales stranded more than any other species, with the entire pod following if an injured or sick whale turns for sheltered water.
“If one does get into trouble the others will be looking out for each other and trying to protect each other. Whereas you might see in orca or in other species of dolphins – where one strands the others will stay nearby in the water free swimming – with the pilot whales they will just come in en masse and a lot of healthy animals will get into trouble and subsequently strand.”
Grover said it was possible the pilot whales had been fleeing from orca, known as killer whales because they hunt the calves of other whales.
New Zealand has one of the highest stranding rates in the world, with an average of 300 whale and dolphin events per year, involving up to 700 animals. Grover said the country’s waters provide rich habitat.
“We span everything from sub-Antarctic waters to sub-tropical waters. Half of the world’s species of whales and dolphins have been observed in our waters,” he said.
For Lamason, whale strandings are all part of the natural order. He said the department would not consider installing sonar beacons to warn the whales away from the area.
“They are coming in here often on purpose. It is a really good hunting ground for them. There is a lot of small bait fish in here and we do have some quite rare dolphin species in here (including) Hector’s dolphins, and the last thing we would want to do is start disturbing those animals and trying to force them out of the bay.”
The Department of Conservation will begin disposing of the carcasses of the 140 dead whales on Monday.
The bodies of stranded whales have been buried on land in the past, but Lamason said officials were trying a new system of tethering the carcasses to posts in the intertidal zone.
Three sperm whales that died in the area last November have been disposed of that way, their bodies providing food for a host of scavenging fish and birds including giant petrels from Antartica, rarely seen in the area.
“It makes me think that maybe leaving them in the intertidal zone is a good thing for us to do. [It is] from the ocean back to the ocean,” he said.