Arctic Science Journeys
STORY: Lower an underwater microphone into the coastal waters of Sitka, Alaska, this time of year, and the ocean's blue-green depths come alive with the feeding calls of hungry humpback whales.
Humpback whales--hundreds of them--have spent their summer here "bulking up." They've consumed vast quantities of small fish and zooplankton, so much that their bodies ripple with layer upon layer of fat. They'll need the extra energy when, during the next several weeks, they begin their annual migration to Hawaii. But even with so many whales around, on this day Sitka whale watcher and biologist Jan Straley has yet to see a humpback.
STRALEY: "The weather is terrible. It's supposed to blow 50 knots on the outside today, and it's probably blowing 35 to 40 knots right now, and it's raining horizontally."
It wasn't a good day for spotting whales, but even so, there have been plenty of good "whale days" lately. Like the day before, which was clear and calm. She saw eight humpbacks--not bad, she says, for just an hour on the water. On even better days, she sees as many as 100.
STRALEY: "This is a great time of the year to be seeing humpback whales close to Sitka in Sitka Sound. Within five minutes you can be near a group of whales. Yesterday there were eight whales. You can see them right from the road system."
Jan Straley studies whales at the University of Alaska Southeast. Each morning, she walks down to the docks, yanks the rope on her outboard motor and points the bow of the 23-foot fiberglass skiff seaward. She ventures only a few miles into the sound--any further and she'd lose the relative protection offered by the sound's numerous islands. Humpbacks, she says, are common here. Several thousand of the mighty mammals spend the summer in the North Pacific Ocean, many of them right here in Sitka Sound.
The humpbacks Straley tracks stay in Southeast Alaska for up to nine months, gorging themselves on the region's abundant plankton and schools of fat, oil-rich herring. Visitors and residents alike watch whales either from shore or from aboard several whale watching vessels that operate out of Sitka, Petersburg, Juneau and Ketchikan. Lately, whale watchers have been getting quite a show.
STRALEY: "What you might see and what we saw yesterday were two groups of whales, a group of three and a group of four to five whales and they were feeding. They were doing approximately six- to seven-minute dives and staying on the surface for ten to twenty blows. So you see them on the surface and they do their terminal dives where they throw their flukes straight up into the air and then they go down deep and come up again. That's about what you see. However this one group had a couple of youngsters in it. They were smaller and frisky; they were throwing themselves out of the water and slapping the water and either a tail swish. It was good whale watching."
The best whale watching months are August through December. By January, most of the whales have begun their migration south to mating and calving grounds in Hawaii. Straley says one of the whales she tracks holds the record for the fastest swim to the tropical island.
STRALEY: "They can get there fast if they want to. The Guinness Book of World Records is going to print this year, for their Christmas edition, that the fastest record is 39 days. They wouldn't believe my 36-day record because it wasn't published. The 39-day transit is also my record."
Being able to swim fast means whales can stay in Alaska longer, building energy reserves they'll need because once they reach Hawaii, humpback whales stop feeding and concentrate on mating and calving. Straley thinks whales that stay in Alaska until the last possible moment may have an advantage.
STRALEY: "Get as fat as you can especially if you were going to have a calf that year. Or if you're going to do two oceanic migrations with a calf and have to nurse that calf, you might want to be as chubby as you can possibly be and still handle the heat in the tropics."
But right now the tropics can wait, because just beneath her skiff are 40-foot whales, interested in nothing more than eating . . . and talking.
OUTRO: For Arctic Science Journeys Radio, this is Robert Hannon reporting from Fairbanks, Alaska.
Arctic Science Journeys is a radio service highlighting science, culture, and the environment of the circumpolar north. Produced by the Alaska Sea Grant College Program and the University of Alaska Fairbanks.
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