The lake as a laboratory

Experts from the Academy of Natural Sciences have gone to the other side of the world to help unlock the secrets of a lake in Mongolia that has gone largely untouched for 40 million years.

Oroginally published on Nov. 14, 1994.

Winter comes hard and early to northern Mongolia. The ground is frosted when we rise, and Clyde Goulden's neoprene chest waders are frozen to the ground beside his tent, as if reluctant to re-enter the icy water of Hovsgol Lake.

Goulden, one of the world's leading aquatic ecologists and curator of limnology (the study of freshwater systems) at the Academy of Natural Sciences of Philadelphia, has been up since before dawn writing in his log book and labeling specimens from his previous night's work. After a cup of coffee and a quick bowl of oatmeal, he will be back in the water collecting more of the endemic fish and tiny invertebrates that have brought him to this mile-high research site in Central Asia.

Hovsgol Lake, one of the most ancient and pristine in the world, lies some 200 miles southwest of its better known sister, Lake Baikal in Siberia, and a 600-mile bone-jarring jeep ride across the Mongolian steppes from Mongolia 's capital, Ulan Bator. It is this rare combination of inaccessibility and age that makes Hovsgol Lake so important for Goulden's research. Unlike the world's few other truly ancient lakes - Lakes Victoria in Malawi, and Tanganyika in east Africa, and even Lake Baikal, all of which have been affected (and in some cases virtually destroyed) by human activity - Hovsgol is still in a virgin state. The deep blue and turquoise water is so pure it can be drunk without fear of illness, and so clear one can see fish swimming more than 30 feet below its surface.

Incredibly, the lake has never been studied by Western scientists - until now. Goulden was accompanied at the lake for more than a week by B. Batjargal, a colleague from the National University of Mongolia. Three other expedition members worked on other lakes in Siberia.

No one knows for sure how old Hovsgol Lake is, but estimates run from 40 million to 60 million years, making it 400 times older than North America's Great Lakes, 20 times older than Lake Tanganyika and second only to Lake Baikal as the oldest lake in the world.

"We have at Hovsgol the aquatic equivalent of the tropical rain forests for biodiversity," explains Goulden in a hushed tone that borders on awe. "Plants and animals have been evolving here without interruption since the days of the dinosaurs."

Goulden has spent more than 30 years studying lakes in North and South America, Africa and Europe, but for him, Hovsgol is by far the most exciting.

"An opportunity for this kind of study is so rare as to be almost unimaginable," he observes. "What's more, there is an opportunity to preserve this beautiful place as an evolutionary time capsule and laboratory for future generations."

The larch- and aspen-studded watershed that surrounds this 4,000-square-mile lake is home to the region's still plentiful populations of wolves, elk, moose, bear, wild boar, sable, Argali sheep and snow leopard. It's designation as a national park was among the first official acts of Mongolia 's new democratic government in 1992. Working in concert with regional administrators, the country's Ministry of Nature and the Environment is now in the process of developing guidelines for the lake's future use.

To help with this, Goulden and a team of American and Mongolian scientists have come to Hovsgol on the invitation of the Mongolian government, the National University of Mongolia, and Khan Altai Foundation, Mongolia's first and only popularly-based environmental organization. "Hovsgol Lake has long been sacred to the people of Hovsgol Aimag (provence)," says Khan Altai's founder and president, Gendenpiliin Yavgaan. "We hope that one day it will be recognized as an international treasure as well. It's spectacular beauty is self-evident" - it's known locally as "the blue pearl" - "but it will take scientific study to confirm its significance as a living museum of evolution."

Extending roughly 100 miles north to the Siberian border from the village of Hatgal, Hovsgol Lake was created by a massive shifting of the earth's tectonic plates. As India moved north to collide with the rest of Asia (forming the Himalayas), Central Asia's tectonic plates shifted east and west to accommodate the pressure, creating the dramatic topography that defines today's Mongolian-Siberian frontier. The Sayan Mountains that surround Hovsgol Lake pushed up, while Hovsgol, Baikal, and a half-dozen other tectonic basins dropped down. Lake Baikal's depth has been measured at more than a mile, making it the deepest land depression on the planet. Hovsgol is today about 800 feet deep, but it grows deeper each decade as Asia's plates continue to move.

Goulden and his colleagues have been traveling through Mongolia and Siberia since late August looking at Hovsgol, Baikal and a number of related tectonic lakes and basins on an expedition sponsored by the Academy of Natural Sciences with help from several Philadelphia-based foundations and a planning grant from the National Science Foundation's Division of International Programs. Of all the lakes he has seen, Goulden considers Hovsgol the most significant. He hopes to translate this year's survey into a long-term study here, beginning in 1995. "We've done some preliminary collecting of fish and invertebrates," explains Goulden, "but we have only scratched the surface."

Though previously unstudied by Western scientists, Hovsgol has been of interest to scientists from Mongolian National University since the early 1970s. In 1989, they produced the first detailed geological atlas of Hovsgol Lake, providing an invaluable base for the biological and evolutionary studies now planned by Goulden and his colleagues. "My hope," says Goulden, "is to work with the university's students and faculty to develop a comprehensive biological inventory of the lake. Once we know what is here, there are any number of exciting questions about evolution we can begin to explore."

Among the issues Goulden wants to investigate is whether Lakes Hovsgol and Baikal were once connected and, if so, for how long. "The point at which they separated is the point at which independent evolutionary processes began," explains Goulden. "By learning more about how life has evolved in these related but quite separate inland seas, we can shed much light on the Earth's history and the nature of evolution itself."

Mongolia, closed to the Western world since the 1920s, is the least densely populated country in Asia, with only 2 million people in an area more than twice the size of Texas. It is also, traditionally, the most environmentally sensitive, with some conservation laws dating to the Middle Ages. A Mongolian law of 1294, for example, forbade hunting or trapping large mammals during their mating and cub-raising seasons, an approach not taken in Western countries until late in the 19th century.

As the country struggles to convert from communism to a free-market economy, its environmental interests persist. "It is significant that Dr. Goulden is in Mongolia at the invitation of the Mongolian people," says Bill Chang of the National Science Foundation. "This is a rare case of mutually beneficial interests: the local people revere Hovsgol Lake and want it protected. Dr. Goulden can help them by better understanding the lake and its ecosystems. Both the people of Mongolia and the international scientific community will be richer for his efforts."

Working conditions at Hovsgol Lake have not been easy. The one large (60-foot) boat that plies Hovsgol (the only vessel in land-locked Mongolia's "navy") has been unable to operate for almost a year due to fuel shortages. Its sister vessel, overloaded with cargo, sank in one of Hovsgol's frequent storms in 1983.

The lake's largest settlement and the most likely base for future studies here is Hatgal, a village of 4,000 people at the southern tip of Hovsgol. It has no electricity, no running water, and is fueled entirely by firewood and yak dung. Even in summer, food is in short supply. Except for wild-gathered nuts and berries, fruits and vegetables are virtually nonexistent. Staples of the local diet include airag (fermented mare's milk), boiled sheep fat and vodka.

"By American standards, these conditions may seem difficult, but one quickly adjusts," says Goulden, laughing, as he struggles into his frozen waders. "The warmth of the Mongolian people more than makes up for the cold . . . and the potential for significant discoveries is enormous. I can hardly wait to come back."

The expedition members, who returned to Philadelphia early last month, are still assessing their collections and planning for their return to Hovsgol Lake next year.