Shark swims 12,400 miles in nine months

October 07, 2005

A 12-foot-long great white shark has made what scientists are calling the fastest-known round-trip ocean migration by a marine animal.

The female shark, dubbed P12, was fitted with a satellite radio transmitter on Nov. 7, 2003, off Gansbaai, South Africa. She turned up 99 days later off the northwest coast of Australia, 6,900 miles away. En route, she made frequent dives to 3,200 feet, into 38-degree water.

Her average speed - 2.9 mph - is the fastest sustained, long-distance speed known among sharks, scientists said. By Aug. 20, 2004, the same shark was back off South Africa, ending a nine-month round trip of 12,400 miles.

American and South African scientists, writing in the current issue of the journal Science, say they don't know how P12 navigated the entire Indian Ocean. But tracking data revealed she spent two-thirds of the trip within 16 feet of the surface, a hint to scientists that the big fish use "celestial cues" to find their way.

They say the new tracking data support previous genetic evidence that female great whites from South Africa mate with males off Australia, then return to produce their young off South Africa.

The sharks' long swim outside protected South African and Australian waters increases their exposure to the international shark fishery. The authors conclude that "global protective measures ... are warranted to ensure the effectiveness of local protective legislation currently in place in a handful of countries."

--Frank D. Roylance

Did you know?

Percy Spencer, a Raytheon scientist, patented the first microwave oven in 1945.

People's Pharmacy

I'm seeking advice regarding "bird" flu. I'd like to try to take precautions now if I can. Is it too late to get Tamiflu? What about masks? What other precautions can we take?

No one knows yet whether the avian flu (H5N1) will mutate into a virus that spreads easily from one human to another. So far, the people who have gotten sick with this potentially lethal virus seem to have caught it from infected birds.

Tamiflu appears to be effective against the H5N1 flu. Some countries are stockpiling this antiviral drug.

If your physician prescribes Tamiflu, you will be able to fill the prescription. Whether a surgical mask or something even more sophisticated could protect you is unclear.

My husband and I have been married for 15 years, but in the past six months I have not been able to keep up with his sex drive. I am only 43, and I would like to return to my former level of interest.

I keep wondering if the medicines I take are contributing to this issue. I'm on Zocor to lower my cholesterol and Prozac for my mood.

I've heard that testosterone can help restore libido, but I am worried that regular use could cause side effects. Could I just take it on weekends?

A number of prescription drugs, including Zocor and Prozac, might lower libido. Ask your doctor whether an alternative might be appropriate for you. The antidepressant Wellbutrin, for example, may be less likely to interfere with sex drive than Prozac.

Testosterone may stimulate sexual desire, but regular use can deepen the voice, cause unwanted hair and lead to acne.

Taking testosterone under the tongue can increase sexual interest several hours later.

In their column, Joe and Teresa Graedon answer letters from readers. Write in care of King Features Syndicate, 888 Seventh Ave., New York, N.Y. 10019, or e-mail them via their Web site: www.peoplespharmacy.org.

In Brief: Fitness

Exercising more, adults report

More American adults appear to be getting off their duffs and engaging in more leisure-time exercise.

Those who say they engage in no physical activity or exercise outside of work declined from 29.8 percent in 1994 to 23.7 percent a decade later, according to surveys of up to 296,000 adults in all 50 states, reported today by the Centers for Disease Control and Prevention.

The steepest gains in physical activity were found among men in their 50s and women in their 60s. Highest inactivity rates were found among Hispanic women (39.6 percent).

Even so, men ages 18 to 39 were the only groups whose activity rates met national goals. Physical inactivity is linked to increased risk for cardiovascular disease, diabetes, osteoporosis and other chronic conditions.

--Frank D. Roylance

Diet

Costly produce bad for the waistline

A new study suggests the price of fresh fruits and vegetables has a stronger connection to weight gain among children than whether they live near fast-food outlets - adding confusion to the muddy picture of what causes youngsters to gain weight.

Advocacy groups suggest a strong link between obesity and the proximity of fast-food restaurants or the lack of supermarkets stocked with fresh food. But the new study by the Rand Corp. think tank, released this week, found little support for that connection.

The study examined the weight gain of 6,918 children of varying socio-economic backgrounds from 59 U.S. metropolitan areas as they advanced from kindergarten to third grade.

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