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Aug 1, 2001 5:00 AMNov 12, 2019 4:52 AM


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More than 70 percent of the Earth's surface is covered by water, but only 2 percent of that is the liquid most vital to humans: freshwater. Worse, most of that is locked in the polar ice caps. Nonfrozen surface freshwater is scattered around the globe in rivers and large lakes, including Japan's Biwa, Africa's Victoria, and Siberia's Baikal. But the largest reservoir of accessible freshwater is often overlooked: the Great Lakes. Together, lakes Superior, Michigan, Huron, Ontario, and Erie contain one fifth of the world's liquid freshwater surface area. Celebrating these assets is the job of the one-year-old Great Lakes Aquarium in Duluth, Minnesota. "The Great Lakes don't get the respect they deserve," says David Lonsdale, executive director of the $34 million 62,000-square-foot facility. "Unless we can build up the importance of the Great Lakes, and excitement about them, we're going to have a real fight on our hands to maintain them for the future well-being of mankind and the Earth."

The nation's only all-freshwater aquarium (www.glaquarium.org) features scores of species of fish— gar, sculpin, whitefish, dace, smelt, and sturgeon (which can live more than 100 years and reach more than 7 feet long), to name a few, as well as dozens of varieties of birds, snakes, salamanders, turtles, and otters in five major habitat exhibits and 19 satellite tanks. The habitats showcase life in and around Superior, the largest of the Great Lakes, with 3 quadrillion gallons of water. The Baptism River exhibit, for example, centers on a fast-moving stream vital to breeding salmon and brook trout, while the St. Louis River exhibit spotlights slow-moving waters that are home to game fish, including perch, walleye, and smallmouth bass. The Pictured Rocks/Kakagon Slough habitat mimics a wetlands area on the lake's southern shores, which is an important spawning ground for fish, thanks to its abundant food and cover and more temperate climate.

In the satellite tanks, the not-to-miss exhibit is sea lampreys. These eellike parasites, which clamp onto fish with their sucker mouths, were accidentally introduced into the Great Lakes about 54 years ago and wreaked havoc on the local fishing industry. The lamprey population is now controlled via the construction of barriers in its breeding grounds and by the use of a chemical that kills lamprey eggs.

Visitors also shouldn't miss the interactive weather station, where they can determine the day's forecast, then walk a gangplank three stories above the ground to check its accuracy. It's harder than it seems. Because of their vastness and the fact that water doesn't change temperature as quickly as air does, the Great Lakes create their own weather. In summer, warm breezes washing over colder water produce cool temperatures and fog. In winter it's reversed: Frosty air gusting over warmer water results in moderate temperatures and copious "lake effect" snow.

After spending several hours indoors gazing at exhibits and reading placards, guests at the aquarium get a terrific bonus: They can step outside and revel in the beauty of Lake Superior itself. Says Lonsdale: "When people get up here and actually see it, they always fall in love."


All Pumped UpForget batteries. This zippy new plane operates the old-fashioned way— on compressed air

High-tech toys may be the rage, but every now and then, don't you long for a less-sophisticated plaything? Something that doesn't have microchips, require battery packs or a computer, and doesn't break your bank account? If so, you're in luck. From Spin Master Toys comes the Air Hogs XT-9 ($30, www.spinmaster.com), an ultralight single-prop plastic and Styrofoam plane that can fly the length of a football field, climb 250 feet into the sky, and even do tricky loops. Air Hogs operate solely on compressed air.

The single-prop Air Hogs XT-9 also has wind-driven rotors on each wing that recall the autogiro, a forerunner of the helicopter, enabling it to do tricky loops and hairpin turns.Photograph courtesy of Spin Master Toys

Delivered through a hand pump that fits on the aircraft's nozzle, the air is forced into the hollow fuselage and held by a ball valve. When the propeller is flicked to start it rotating, its shaft pushes a connecting rod down into a spring-loaded piston that in turn forces the ball valve down. The high-pressure air rushes into the piston chamber, forcing the piston back up and putting the ball stopper back in place. The piston pushes the connecting rod, which turns the propeller. The air that drove the piston escapes through an exhaust hole at the top of the piston chamber, and that plus the now-spinning propeller's inertia makes the piston fall and start the cycle over. The process is quick: The plane's propeller turns 4,000 times a minute.

The XT-9 also boasts free-spinning unpowered rotors on each wing to add lift and allow the plane to almost hover during flight. The design recalls the precursor of the helicopter, the autogiro. First successfully flown in 1923, it used a single large top rotor that spun in reaction to the craft's forward movement. The XT-9's two rotors also give it the ability to do quick turns and loops in flight; wind blowing from the side causes one rotor to turn more than the other, giving more lift to that wing. However, perhaps due to a strong head wind and lack of flying practice, this pilot was unable to successfully perform complex maneuvers. Still, putting a little elbow grease into pumping will make the XT-9's flying time unlimited, so you should easily reach ace status in no time. Fenella Saunders


Dive Right InPerfect reads for summer address the wonders and perils of water

Writing on Water Edited by David Rothenberg and Marta Ulvaeus The MIT Press, $24.95.

Rothenberg and Ulvaeus have put together an engrossing mix of environmental reporting, meditative essays and poems, and evocative photos and art, all around the theme of water.

H20: The Beauty and Mystery of Water

Hans Silvester, Bernard Fischesser, and Marie-France Dupuis-Tate Abrams, $49.50.

Photographer Silvester's dramatic photographs of geysers and glaciers, rain clouds and snowfalls, along with graceful text by agriculture and forestry engineer Fischesser and ecologist Dupuis-Tate, illuminate how water has shaped the land and our lives.

Reefscape: Reflections on the Great Barrier Reef Rosaleen Love Joseph Henry Press, $24.95.

Love leads readers on a scientific and poetic tour of the stunning natural formation off Australia's eastern coast.

Blue Frontier: Saving America's Living Seas David Helvarg W. H. Freeman and Company, $24.95.

Helvarg sounds a loud wake-up call to the myriad threats, including overfishing, development, and pollution, that are imperiling our greatest environmental treasure.

Twelve Days of Terror: A Definitive Investigation of the 1916 New Jersey Shark Attacks

Richard G. Fernicola, M.D. The Lyons Press, $27.95.

Shark Attacks: Their Causes and Avoidance Thomas B. Allen The Lyons Press, $24.95.

Fernicola's gripping re-creation of a notorious incident at the New Jersey seashore and Allen's comprehensive examination of sharks and their behavior are guaranteed to keep you out of the water and in your chair on the sand this summer

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Liaisons of Life: From Hornworts to Hippos, How the Unassuming Microbe Has Driven Evolution

Tom Wakeford John Wiley and Sons, $24.95.

Biologist Wakeford charmingly chronicles the once-heretical notion that symbiosis among plants, animals, and microbes is a major evolutionary force. Big surprise: Beatrix Potter was hounded out of a career in biology for espousing the idea.

In Code: A Mathematical Journey Sarah Flannery with David Flannery Workman Publishing, $24.95.

An Irish math prodigy tells how an algorithm she developed at age 16 revolutionized Internet cryptography.

Arctic Refuge: A Circle of Testimony Compiled by Hank Lentfer and Carolyn Servid Milkweed Editions, $15.

In short (and sometimes quite moving) essays and poems, scientists, native Alaskans, and former U.S. president Jimmy Carter warn against drilling for oil in the Arctic National Wildlife Refuge.

The Second Death of George Mallory: The Enigma and Spirit of Mount Everest

Reinhold Messner St. Martin's Press, $23.95.

Assuming Mallory's voice, legendary climber Messner mourns the disappearance of the spirit of amateurism that once drove adventurers to scale the towering peak.

Atom: An Odyssey from the Big Bang to Life on Earth. . . and Beyond

Lawrence M. Krauss Little, Brown and Company, $26.95.

In an engaging tour de force, physicist Krauss examines the universe and life by following a single oxygen atom on its journey from birth in an exploding star 12 billion years ago to its disintegration billions of years in the future.

Ancient Sichuan: Treasures from a Lost Civilization Edited by Robert Bagley Princeton University Press, $60.

A richly illustrated volume documents the trove of bronze, gold, jade, amber, and clay artifacts dating back to the 13th century B.C. that were unearthed from sacrificial pits discovered in China in 1986. An exhibit of objects is now at the Seattle Art Museum and will travel to Fort Worth, Texas; New York; and Toronto.

Why Elephants Have Big Ears: Understanding Patterns of Life on Earth

Chris Lavers St. Martin's Press, $24.95.

If you've wondered why reptiles dominate swamps or why the big land animals are all mammals— in short, why certain animals predominate in certain environments— ecologist Lavers has the answers.

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