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Scientists witness Whale researchers recently saw a rare event: the death of a humpback whale calf while being supported by its mother in waters off West Maui.
whale calf’s death
The humpback whale calf and
mother were spotted off West MauiBy Helen Altonn
haltonn@starbulletin.com"We've been doing research here since 1975, and this is the first time we actually witnessed any whale die," said Mark Ferrari of the Center for Whale Studies.
Dan Salden, founder and president of the Hawaii Whale Research Foundation, said a commercial boat reported sighting the mother and calf about 1 p.m. Feb. 28.
His boat arrived first at the scene and was joined by Adam Pack's group from the Kewalo Basin Marine Mammal Laboratory, and Mark and Debbie Ferrari of the Center for Whale Studies. All were in the area studying whales.
The scientists were distressed that they were unable to get permission from the National Marine Fisheries Service to take the calf's body to shore for an autopsy.
"An important opportunity was missed to learn why this calf died," said Pack, assistant director of the Kewalo laboratory.
Margaret Akamine-Dupree, with the Fisheries Service's Pacific Islands Area Office, Protective Species Program, said the researchers were allowed to take skin samples from the calf, but "it was too logistically difficult" to take the calf into shore.
She said she talked to state and Coast Guard officials and others about the request, but it was getting dark, equipment was not available, and there were a lot of public health and safety concerns.
"Bringing the animal in and doing a necropsy would be a good idea, absent the other public health issues involved," she added, noting there were already sharks in the water around the calf.
"No one likes it when these animals die," she said, pointing out the fisheries service, as well as researchers, want to get as much information as possible about humpback whales.
She said the agency would like to come up with a plan of action that could be initiated when needed and where equipment and expertise were available. A workshop will be planned to discuss the issue with scientists holding research permits, she said.
Using special techniques, the Kewalo researchers estimated the calf was 15 feet long and the mother 43.5 feet long. Based on the growth curve, they calculated that the calf was 27 days old.
Many people looked down on the scene from the Honoapiilani Highway while the calf struggled for survival. The researchers do not know if the calf had genetic problems, a disease or was affected by something else.
"Probably the biggest loss is, we may never find out what was wrong with the calf," Ferrari said. "It was a rare opportunity to get into the lives of these animals."
Pack said the calf appeared to have a spinal deformity in front of its dorsal fin that caused difficulty in swimming. Its dorsal fin also was completely flopped over, and its tail flukes and pectoral fins appeared weak, he said.
Deaths of humpback whale calves are estimated at 15 percent to 25 percent but rarely observed, he said.
"The calf's breathing rate was rapid and appeared labored, about nine breaths per minute compared to the mother's two breaths per minute," he said.
When a shark approached, he said, the mother swam about 100 yards from the calf and "performed a series of powerful breaches" before returning to the calf, slapping its 15-foot long pectoral fin on the water surface and lifting the calf up to the surface.
"Over the next two hours, the calf and mother continued to mill slowly and drift southeast toward McGregor Point," Pack said. Occasionally, the calf strayed from the mother, which made him think it might be stronger and survive, he said.
But at 4:49 p.m., he said, "The calf now resting almost exclusively on mom's rostrum began undulating its head at the surface continuously as if it was having seizures. The calf's breathing became heavier and more rapid.
"The mom swam slowly forward with the calf, now nearly completely out of the water on her rostrum. Three minutes later, the calf rolled onto its side and was not breathing."
Moving closer, the researchers determined the calf had died, Pack said. "It was heart-wrenching."
He said the mother "immediately began pushing the calf, lifting it up on her head and putting her pectoral fin over the calf's body."
Then she moved about 200 yards away from the calf and remained there for half an hour, he said. "We then saw a tiger shark within 20 feet of the dead calf."
Pack said he positioned his boat closer to the calf's body to protect it and tried on short notice to get permission to take the body ashore.
He said he understands concerns about sharks following the carcass to the shoreline and posing a public threat. But he said, "It is a pity that Hawaii does not have a better system for responding to tragedies of this sort, like other coastal areas of the United States."
Salden said the researchers met in January and discussed obstacles of retrieving entangled and stranded animals and getting approval to react to emergencies.
On the same day of the calf's death, Salden said, he saw a deserted calf going to boats and rubbing up against the hull. It was the second calf he had seen in two weeks without its mother, he said.
"Theoretically, there could be something going on in the area and a lot of these calf things related," he said. "If that's the case, we need to learn about it so other calves are not put in similar peril."
The day after the calf died, Pack said the mother was observed in a highly aggressive group of 14 males physically competing for the principal escort next to the mother.
He said it is important to learn if the mother had other calves, and the Kewalo lab is searching its photographic database of tail flukes of more than 4,000 humpback whales to find a match for the mother.