Sex, Drugs, and Public Health

February 12, 2014

DAY FOUR AT SEA

Filed under: Uncategorized — cbmosher @ 9:54 am

Lying in the shallow ocean water, just beyond the beach where penguins stumble and trip over pebbles, is a bone. It’s a rib. The rippling water distorts it to our eyes, but it can’t distort this: the rib bone is twelve feet long.

Late 1700’s, to mid  1900’s (Yankee whalers were working Antarctica in 1791) , they slaughtered whales and brought them to this beach to take the oil. The rest they dumped. Whale populations fell to low single digits of what they had been for centuries before. Wasn’t til after WW II that pressure from those who care (the term “environmentalist” didn’t exist yet) slowed, and eventually halted the slaughter. (Well, almost halted it. There’s still one country that hunts here “for scientific research.” A loophole in the international agreement).

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In this place, where there’s almost no Life on land, where it occurs beneath the ocean’s surface, sightings of whales became rare. Even within the lifetimes of the scientists who take these voyages with us paying customers, a whale sighting might occur only once every four voyages or so.

But we’ve seen both Killer Whales and Humpbacks off our bow the past two days, and yesterday we got a whole lot closer.

The Killers – species name “orca” – are easy to spot by their paint job. They all must surface to breathe – exhaling at 200 miles an hour and exchanging CO2 for oxygen in their lungs at an efficient 85% (our exchange efficiency is 20% or so for a single breath). But the scientists have found some substantial differences, using study tools of cameras and crossbows. The whale’s dorsal fin breaks into the air with each breath, and if the scientist’s boat is close enuf, his arrow plants a temporary tracking devise on the fin. Did that yesterday.

This way, they’ve found three groups – the Killer Whales in each group have different patterns of coloring, they hunt in different areas of Antarctica, and they eat different prey. One prefers seals, another a single species of Antarctic fish, and the third eats other whales.

So, they no longer call these whales “Orcas.” They believe that there are three or four different species of Killers, and the taxonomy must change. Only one of the four will keep the species name “orca.”

Twice now we’ve seen a half dozen Killers within reach of our eyes.

4 Killer Whale

Two nites ago and again yesterday when our ship followed a blow, geysering from the water, the animal whose spine curved out, up, and back below the surface was much larger than a Killer’s. Like a fat submarine, black Humpbacks surfaced to breathe while feeding. We could predict where they’d surface again by the bubbles breaking the surface.

When these whales find their preferred food, they often get below their prey, swim in a circle, and blow bubbles. The rising cylinder of bubbles acts like a cage, trapping their prey. Then they open their mouths and swim up thru their cylindrical trap, engulfing everything in there. Using their one-ton tongue, they squeeze out the water from their mouths, and swallow.

Ironic that the bigger whale (up to 50 feet long and approaching 50 tons) eats stuff that’s smaller than the Killers’ prey. Much, much smaller. They eat krill – a 2 inch long shrimp-like animal.

Yesterday we cruised a bay here, in the Zodiac, and a mother and calf, probably just weaned from her very thick and rich milk, surfaced and blew nearly within arm’s reach of our inflatable 22 foot boat. Reminded me of standing on friend’s 40 foot sloop in San Francisco bay, as a Chinese container ship passed by us, eclipsing the sun.

In that bay, dense with floating bergs, we saw at least a half dozen Humpbacks in less than an hour. Good news for species recovery after teetering on extinction’s cliff.

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The food chain here is real simple. Diatoms (some of you may know “Diatomaceous Earth,” the shells of these microscopic phytoplankton) bloom in these nutrient rich, very cold waters. The krill eat the diatoms as long as the water temp is colder than 4 degrees C. ; penguins feast on krill; seals eat penguins; some whales eat seals. Other whales, like the Humpback, by-pass intermediary steps and eat krill directly. Up to a ton of it a day.

Tommorow – diving in the Southern Ocean

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