Lifeguard Joshua Jadolon doesn't need a scientist to tell him the Great Lakes are receding.
It's all in the sand, he explains.
"Feel this sand," he says. "It's really rough." He lets it run through his stocky fingers. "The sand up there is really fine," he says, pointing to last year's shoreline 15 feet up the beach.
Mr. Jadolon, clad in red shorts and a red safari hat, has been patrolling Milwaukee beaches for the past six summers. Each year he finds the shore farther away.
Longtime lake dwellers will tell you that highs and lows are part of the water's charm, with levels rising and falling by several feet each decade. But now that water levels are at a 35-year low, the Great Lakes' lovable quirks have become serious problems for everyone from shippers to water skiers.
As scientists try to understand why lake levels have dropped faster than ever before during the past three years, boaters are finding their piers useless and entire marinas are becoming beaches. More than that, freighters are leaving hundreds of thousands of dollars' worth of cargo at the dock in order to navigate shallow harbors.
With no end in sight, recreationists and fresh-water sailors are worried that this might be more than a cycle of nature.
"This drop in lake levels is unprecedented; it is the largest drop in the past 100 years," says James Lubner, a biologist with the University of Wisconsin's Sea Grant Institute, part of the Great Lakes Research Facility in Milwaukee.
Since 1997, lakes Erie, Huron, and Michigan are down by more than 3 feet. Lakes Ontario and Superior are down by 1-1/2 feet. Overall, that's a loss of some 63 trillion gallons.
Debate over the cause
But while scientists agree that the drop in water level is significant, they disagree on the cause. The culprits: drought, heat, La Nia, and human impact.
Dr. Lubner points to hotter weather. Contrary to popular belief, he says, precipitation has been good. May, for instance, had above average rainfall.
Yet warmer summers have increased the amount of heat stored in lakes, increasing evaporation. "We've had significant evaporation in the face of near normal precipitation," Lubner says.
Low lake levels are much harder to cope with than high lake levels. "There are certain things you can do to protect yourself from flooding, like moving water around in the system," says Michael Donahue, executive director of the Great Lakes Commission in Ann Arbor, Mich. "It's pretty hard to add more water when there isn't any to add."
For his part, he lays the blame on lower-than-average precipitation and higher-than-average temperatures. But he also notes that climate fluctuation is becoming more extreme, and that could be leading to extreme fluctuations in the lakes. Ten years ago, the lakes were at record highs.
"From here on out, we may see much more variable weather patterns and wilder swings as the climate is becoming more variable," says Dr. Donahue.
Ship companies are already feeling the bite. They work on a slim profit margin and normally try to carry the maximum amount. But the 1,000-foot iron-ore and coal carriers are leaving as much as 6,000 tons on the docks to avoid hitting bottom in certain ports. Six thousand tons is worth more than $200,000.
The Lake Carriers Association in Cleveland estimates that the losses could run into the millions as ships make more trips.
Deep in the port of Milwaukee
So far, Milwaukee hasn't had major problems with low water, since its harbor is naturally deep. Inside a warehouse here, dockworkers prepare to load an incoming ship bound for India with bags of wheat and corn. In another warehouse, steel rolls wait for a train.
"Everything from beer to brassieres to chocolate comes through this port," says Kenneth Szallai, director of the Port of Milwaukee. "Coal, grain, steel, iron, frozen butter, dried milk, you name it."
The port is affected by low water levels in other ways, though. More carriers are having to unload part of their shipments in Milwaukee before pulling into shallower ports to unload the remainder.
"When I first got here [in the mid- 1980s], the chief engineer gave me some advice about the people complaining that the lake was too high," says Mr. Szallai. "He said, 'Wait a couple years and people will be complaining that the lake is too low.' And he was right."
Many commercial ports and towns have set aside money for dredging. Also, residential requests to the Army Corps of Engineers for dredging permits have doubled since last summer.
At a downtown marina, Mark McBride is just coming back from a day aboard his boat, the PDQ. Many marinas have installed floating docks that move up and down with the water levels, but that hasn't happened here at McKinley Marina. Instead, owners have had to build ladders to reach the boats.
"You can see how far down those steps go. That's almost 3 feet," he says, pointing to makeshift ladders and once-submerged rusty poles. "I've heard some boats have had problems dragging the bottom."
While much of the country still continues to struggle with drought, places west of the Great Lakes have been getting plenty of rain in recent months. But according to the Army Corps of Engineers in Detroit, Lakes Huron and Michigan - the hardest-hit - are still 20 inches below average.
Adam Fox, a hydrologist with the corps, places part of the blame on La Nia, a cooling of the eastern Pacific Ocean that brings dry hot summers to the Midwest. "La Nia seems to be backing off, which may mean the lakes will return to normal," he says.
Still, no one has been able to accurately predict changes in the lake levels. The Army Corps of Engineers only makes predictions up to six months. Even with a forecast, engineers say, there's little they can do to prevent the changes.
(c) Copyright 2000. The Christian Science Publishing Society