"The great Leviathan is that one creature in the world which must remain unpainted to the last." Moby Dick; or, The Whale, Herman Melville
This past week, one more brush stroke was added to the unfinished portrait of the great whales, and this stroke illuminated a truth that's astonishing. Whales aren't only enormous in three dimensions, they're equally ponderous in the fourth.
Biologists, long stumped at figuring out how old whales are, lucked out when a 50-ton bowhead caught off Alaska came with a telltale clue: fragments of a harpoon lodged in a shoulder bone.
The weapon was used more than a century ago by whalers from New Bedford, enabling researchers to estimate that the whale was at least 115 years old and providing more evidence for their long-held belief that the bowhead whale is one of the longest living mammals on earth, surviving for up to 150 years.
The bowhead harpooned for a second time by Alaskan natives this spring, was swimming the sea at least since Grover Cleveland was the President of the 47 United States. When it was struck by that first harpoon, Thomas Edison was working on the two-way telegraph, Tchaikovsky was still writing his Sixth Symphony, and the rules of basketball were just being published.
While annual rings reveal the great old age of trees, and wonderfully tiny rings in coral can record information as fine as a single day, the age of some organisms is much harder to determine. This is particularly true of aquatic organisms. Up until a decade ago, most scientists thought that bowheads, like many species of whales, had a lifespan similar to that of man -- 60 to 80 years. But discoveries made since then (including structures within the eye of the whale), indicate that the bowhead can live to be 150, or even 200 years or more. There may in fact be bowhead whales still out there, who have been plying frigid Arctic waters since the days when Jefferson negotiated the Louisiana Purchase from Napoleon. There could be several survivors who predate the Civil War. I would say "many," but we nearly managed to exterminate the bowhead around 1900, so there aren't all that many potential ancients.
The great age of these animals can only add to our wonder when viewing a whale, and we can't help feeling a bit of relief that bowheads (unlike some other species) are no longer at the brink of extinction. A whale being born today might still be swimming the oceans of the 23rd Century, assuming we don't screw things up too badly (insert Star Trek joke here).
But the great age of the "great leviathan" can also help to disguise its plight. Because whales are so long lived, problems that affect the reproduction of these animals can take decades to become apparent -- something that should be factored in before anyone considers allowing more whales to be killed. Similar situations have been seen in freshwater animals. The American Paddlefish (and ten points to anyone who knew I couldn't get through a post about large creatures in the water without mentioning the paddlefish) has a lifespan just as mysterious as the bowhead's. Some ichthyologists have given them a projected lifespan of fifty years. Others have suggested that the paddlefish might swim for more than a century in the lakes and rivers of the central United States.
This long life may have served to disguise problems when over fishing in the nineteenth and early twentieth century greatly reduced the paddlefish's range and numbers. For species that live only a season or two, problems rapidly become apparent, but when someone snags a six-foot fish from the Mississippi today, we have no idea if it was born in clear waters of an Ozark stream a century ago, or whether it survived a youth spent in waters muddied by dams and agricultural activities. We won't really know what we're doing to the paddlefish -- or the bowhead -- within our lifetimes.
We'll have to wait for theirs.
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