KILAUEA — Underwater titans surround Kauai every winter. But the pods of North Pacific humpback whales rarely share much more of their lives than an occasional spout or breach seen off-shore. Why exactly the whales make the 2,500-mile journey from
KILAUEA — Underwater titans surround Kauai every winter. But the pods of North Pacific humpback whales rarely share much more of their lives than an occasional spout or breach seen off-shore.
Why exactly the whales make the 2,500-mile journey from Alaska to the Hawaiian Islands is still a mystery to ocean experts, but they have a few ideas.
“We really don’t know why they come, but we’re glad they do. We believe they come here to give birth, to mate, and to sing,” said Kalasara Setaysha, chair of Kohola Leo, a Kauai-based organization that shares information on the whales and their challenges. “We assume they come for the warm waters, but we know that the calves don’t need the warm waters, we know they are born with enough fat to be born up north.”
Humpback whales were designated as endangered in 1970, four years after the International Whaling Commission prohibited commercial whaling of the species. At that time, according to Setaysha, 1,200 humpback whales were making the trek south.
Now there about 21,000 gentle giants making their way on the longest whale migration in the world, from their Alaskan feeding grounds to their Hawaiian bedroom.
“There’s no food for them here,” Setaysha said. “They fast for the six months that they (come) here and then they go back to Alaska.”
The journey takes the whales a month or two to complete. They usually surround the islands from December to April. Setaysha said she’s seen whales in the area all the way into June, however.
The humpback gestation period is 11 months long and most of the calves are born in late December and early January. The moms and their newborns usually stay around the islands, but they don’t just stay near Kauai — they wander around all the islands while they’re here.
The males have been known to wander even further. Some are seen in Hawaii one week and then they’re spotted in Mexico a week later, Setaysha said.
Before the male whales abandon the islands, though, there’s a mating season where competition is the name of the game.
Setaysha said she’s watched what are called heat runs, or the mating dances of the whales. A group of between five and 20 male whales will congregate around a female during a heat run, and they’ll ram each other, vying for what’s called the escort position.
“That’s the place right next to the female,” Setaysha said. “Whoever gets that position and holds it is the winner, but that doesn’t mean he gets her. She chooses what mate she wants.”
When they’re not fighting over the ladies, and usually only when they’re alone, the male whales sing.
“All whales sing the same song, and the song changes throughout the season,” Setaysha said. “A song lasts about 20 minutes, but they can repeat the song for up to 24 hours. There’s phrases, there’s chorus, and there’s rhymes. It’s a never-ending story.”
The melodic story changes as their time in island waters passes, and Setaysha said when that song evolves, the message doesn’t take long to make it to the other whales.
“It seems to spread instantly,” Setaysha said.
No one knows why the whales sing, Setaysha said, but what is known is that their language is highly complex.
“We know they have names and dialects. They’re sentient, self-aware animals, similar to humans and they’re problem solvers,” Setaysha said. “They can plan for the future, they mourn the dead.”
Numbers on rise, but threats remain
Whale numbers are climbing and the National Oceanic and Atmospheric Administration is talking about taking them off of the endangered species list, but the humpback whales of the North Pacific still have threats to their existence.
Marsha Green, president of the Ocean Mamma institute, has been studying the effect underwater noise pollution has on the whales for decades. She was instrumental in the 2015 ruling that the Navy limit sonar use in the oceans between Hawaii and Southern California. She said human-generated noises can be dangerous for the whales.
“We know that whales are auditory creatures,” Green said. “They’re not visual creatures, like humans; they use their hearing to find food, for communication, and for navigation. Hearing is their most important sense.”
Extra noise, even boat engines, can mask their ability to effectively communicate and navigate.
When whales come in contact with boats, Green said, they generally dive deeper and stay underwater longer. They also stay in one place.
“I think they’re not swimming because if they swim, they use a lot of oxygen,” Green said. “It’s pretty much that they’re diving down to avoid the boat, it’s their way of hiding.”
Whales hide from boats when the noise level reaches about 120 decibels, Green said, and sonar is “hundreds of times louder than that.”
Those kinds of loud sounds can break the whales’ eardrums and cause brain bleeding. It also can cause disorientation and live strandings.
While noise pollution is a hot issue currently, it’s not the main threat to whales. The biggest hang-up for a whale is getting caught in a net.
Around the world, 1,000 whales die from net entanglement every day, according to Green. Setaysha said it is estimated that more than 60 percent of North Pacific humpback whales have been, or are currently, entangled.
“I’ve seen them wrapped around their whole body, through their mouth, cutting off their tail, squeezing the body as it tightens,” Setaysha said. “It cuts into their flesh, so the immune system is compromised and they get sick and it’s excruciatingly painful.”
The Hawaiian Islands Humpback Whale National Marine Sanctuary has a disentanglement program, coordinated by Ed Lyman, that spends much of the season freeing entangled humpbacks.
“A lot of industrial fishing nets have metal inside the nylon weave, if they could learn how to make break-away nets, or if we could track the nets to the fisherman that lost them,” that would help end entanglement, Setaysha said. “That’s in process.”
Though they face challenges, the cetaceans appear to still be committed to their pilgrimage. Setaysha said the best way to get a glimpse of a whale is to take a tour with one of the boats that leaves from Port Allen, but you can see them all over the island.
“Look for spouts, breaches, pec slaps and tail slaps,” Setaysha said. “They’re everywhere.”
