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Sonar is a huge threat to beloved blue whales
Is it possible to feel nostalgic for a place you’ve never been to? And is it possible to feel empathy for members of a different species?
In an article about an old friend who had recently died called Grown Men, Oregon writer Barry Lopez compared the life of his friend to the lives of whales. Like his old friend, Lopez described whales as creatures who lead obscure but exemplary lives, creatures who are for the most part undisturbed and seem to be at home in their environment.
I was thinking about Lopez’s whales when I saw a recent article describing how the songs that whales use to communicate, orient themselves and find mates are being drowned out by human-made noises. Increased commercial ship traffic, seismic surveys and a new generation of military sonar are all playing a part in confounding whales and further threatening their very survival.
In just one example, beached whales are turning up on the world’s beaches with tissue damage similar to that found on divers suffering from decompression sickness, which is caused by surfacing from underwater too rapidly.
Scientists suspect that the use of military sonar and seismic testing may be frightening the whales into diving and surfacing beyond their physical limitations. Another study has shown that the blue whale, which used to communicate across entire oceans, has lost 90 percent of its range over the past 40 years.
You’ve got to feel sorry for the blue whale. It is the largest animal on the face of the earth, reaching lengths of over 100 feet and weights of 150 tons or more.
In fact, it is the largest animal that has ever existed. Its tongue alone weighs as much as an adult elephant. Its heart is the size of a Prius. It has blood vessels wide enough for a grown man to swim in. It swims at speeds of up to 20 knots.
In one of those odd juxtapositions that offer proof that God has a good sense of humor, or at least a fondness for the absurd, this largest of earthly creatures feeds almost exclusively on one of the smallest, consuming up to 40 million krill every day. While its fully expanded mouth can hold up to 90 tons of food and water, the dimensions of its throat do not allow it to swallow anything bigger than a beach ball.
Blue whale calves are 20 feet long and weigh nearly three tons at birth. They consume up to 150 gallons of fat-rich milk every day, gaining 200 pounds every 24 hours, or only slightly less than a typical Thanksgiving weekend for me.
They are at home in every ocean on the planet but, like college students at spring break, every winter they head to warmer tropical climates to breed. Scientists think blue whales live to be about 80, but nobody knows for sure because much of the life of Balaenoptera musculus remains a mystery. Unlike college students, little is known about blue whale mating rituals.
They usually travel alone or in pairs, and scientists don’t even know exactly where their breeding grounds are. We don’t really even know the precise purpose of their songs, deep and rhythmic vocalizations lasting between 10 and 30 seconds that used to carry for a thousand miles undersea, often falling just below the range of the human ear.
Herman Melville called them sulphur bottoms in “Moby Dick” because of their distinctive coloring. They exist in the same family as minke whales and humpbacks, and were once called Sibbald’s Rorquals. The blue whale’s only natural predator is the orca, but its primary predator has always been man.
From 1900 to the mid 1960s, the blue whale was hunted nearly to extinction. From a population of some 350,000, only 5,000 to 12,000 remain today, spared by the belated protection of the International Whaling Commission in 1966 after more than 90 percent of the world’s population had been killed.
Because of its long rate of gestation period (over a year) and small litter size (only one or two calves at a time), whale populations take significantly longer to recover than smaller mammals that reproduce much more rapidly such as mice, rabbits and college students.
Although I’ve never met one, I hate to contemplate a world without blue whales and their obscure but exemplary lives. Ask not for whom that sonar sounds; it sounds for all of us.
Islander Tom Tyner is an attorney
for the Trust for Public Land. He is author
of “Skeletons From Our Closet,”
a collection of writings on the island’s latte scene.