Whales are moving to new locations, and dying off, at a great rate. Some may be moving because they sense a change of temperature in the deep ocean, while others are dying off in their traditional waters due to toxins and noise pollution.
A large number of endangered sperm whales are making a home in the Gulf of Mexico, near the dangerously busy mouth of the Mississippi River, a few miles from the Louisiana coast. Sperm whales usually hunt far out in the ocean and it is unusual for them to remain so close to shore. Also, the presence of the approximately 500 of these creatures, some of them bigger than a Greyhound bus, presents a danger to the supertankers, barges, trawlers and warships in the area?and the ships could prove dangerous to the whales.
Scientists are undertaking two research voyages to learn why these waters have become an oasis for the whales. Biologists will attach digital tags to track the whales by satellite. They also will collect skin samples for DNA tests to determine whether the whales are newcomers or have lived in the northern Gulf for generations.
But the real danger to the whales, researchers say, is noise. The increasing industrial cacophony below the waves ? propellers, diesel engines, seismic booms, grinding drills and sonar pings ? could damage the whales? sensitive communications and navigation organs, with potentially fatal consequences.
?We didn?t expect to be running into sperm whales right off the Mississippi Delta, in the middle of all this activity,? said Randall Davis of Texas A&M University at Galveston. ?Their endangered status is supposed to afford them additional consideration for their protection. But these whales have not yet received a lot of attention.?
The northern Gulf is also one of the world?s most important oil fields. Drilling in deeper waters is a major part of the White House?s plan to expand energy production. At least 45 rigs in the Gulf operate at depths of 1,000 to 10,000 feet. Sperm whales are among the few creatures that can dive that deep. Industry officials say oil companies are exploring how to drill safely around the whales in compliance with the federal Endangered Species Act and the Marine Mammal Protection Act.
Several factors are drawing the whales closer to shore, scientists believe. First, the Continental Shelf plunges 1,000 feet just a few miles offshore. Sperm whales typically hunt in deep water and submarine canyons. Also, swirling warm and cold currents mingle waters from the Atlantic and Caribbean. Biological diversity erupts where these eddies converge. A third factor is the huge volume of freshwater pouring from the Mississippi River. It seeds the ocean with nutrients, spawning a rich food chain.
In recent years, fertilizer and livestock manure flushing from the nation?s Farm Belt have triggered an ecological chain reaction that depletes the water of oxygen, suffocating marine life. Yet the whales are flourishing on the deep-water edge of this ?dead zone,?and scientists can?t figure out what they could be eating. It?s another question researchers will try to answer this summer.
According to Robert Gisiner, of the Office of Naval Research, surviving marine life may be hiding there, trying to avoid tuna and other speedy, predatory fish. ?Whales are expert oceanographers,? he says. ?They?re having a field day.?
While the Gulf is gaining sperm whales, the creatures made famous by Moby Dick, San Juan Island, off Washington State, is losing its beloved orcas. Dozens have washed up on the beaches, including a mother with her young calf. The orcas have returned to the waters of Haro Strait to feed each spring for 10,000 years.
?We have had so many losses, I thought, ?Well, we are at the bottom,?? says Astrid Maria van Ginneken, a professor from the University of Netherlands who is studying the Orcas at the Center for Whale Research. Then the center announced that another 7 whales were missing and presumed dead, reducing the local population to 78. ?I thought, ?Oh God! This can’t be true,?? van Ginneken says. ?I thought, ?Where is this going to end???
Many things have gone wrong in the orcas? home waters: there are dwindling runs of their favorite salmon and toxins dumped in the water that accumulate in their fat. Several studies have suggested that an increase in underwater noise from boat engines and depth finders may be damaging orcas? hearing. ?It?s sickening; it?s sad,? says Carey Worthen, who keeps his 36-foot Maine lobster boat in Friday Harbor. ?And the season?s not over yet. I?d be surprised if we don’t lose another one or two whales.?
Van Ginneken estimates the chances of the whales returning at less than one percent. Mark Anderson, who heads the organization Orca Relief, agrees. ?When social structure is damaged, the death rates may go up.?
?It?s a real blow to the heart to realize that the family of whales is eroding,? says Gary Boothman, the mayor of Friday Harbor. ?It seems to be a symbol that a lot of things we?ve taken for granted are slowly going away.?
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