As a chemical compound,  nothing could be simpler than water: two atoms of hydrogen joined to one of oxygen. From a human point of view, simplicity fades. Though water covers our world, more than 97 percent is salty. Two percent is fresh water locked in snow and ice, leaving less than one percent for us. This “precarious molecular edge on which we survive,” as Barbara Kingsolver says in this month’s special issue, will only grow more precarious. By 2025, 1.8 billion people will live where water is scarce.

In the pages to come, we bring to life the drama behind that statistic. And this is only the start of a larger commitment, at the magazine and throughout the National Geographic Society, to explore the world of water. To that end, the Society recently named Sandra Postel its first National Geographic Freshwater Fellow. As a researcher, lecturer, and writer, Sandra has worked in the field of sound water management for 25 years. The initiative she heads will not only educate; it will “reshape how people and communities think about, use, and manage fresh water. It will provide the tools to enable individuals, corporations, and communities to become part of the solution,” Sandra says. 

Vernon Yates took one of his 18 tigers to a party—his fee varies by event. “You can’t trust tigers,” a guest said. To prove her wrong, he told her he’d stick his head in the animal’s jaws and tug its tongue for $20. She had to pay up.

The antlered animals weren’t made for this—to stumble onto a boat in the middle of an autumn night and bump and sway on the water for six hours until they attain solid ground again and resume their overland migration to a winter refuge. In Norway, both reindeer and their seminomadic herders, members of the indigenous Sami, are struggling to find their balance as development intrudes on traditional grazing lands, changing the way humans and animals move.

When Louisiana lawmakers named the brown pelican the state bird, they missed an important point: There were no brown pelicans left there. That was in 1966, after years of pesticide runoff had ruined eggs and silenced once teeming coastal rookeries. Not long after the legislative gaffe, biologists set about reviving the state’s nesting colonies, relocating young birds from Florida. It was a huge success: 350,000 pelicans were born in Louisiana after 1971. Then came the hurricanes.

The muskox may look otherworldly, but it’s very much a creature of the Earth. In fact, this 800-pound primal relative of sheep and goats has roamed the Arctic for about a million years, since the Pleistocene. Scientists want to make sure it stays around for a long time to come. 

Call them cougars, mountain lions, or pumas. Americans think they see them everywhere. That’s no surprise in the West; strict management helped the predatory cat make a remarkable recovery after “varmint hunters” took numbers very low by the mid-1900s. Eastbound cougars are also turning up in the Midwest. South Dakota has a breeding population of 200-plus; just last year, Chicago cops cornered and shot one on the North Side.

There’s no question we love the Atlantic bluefin tuna (above). The problem is we love it only for its taste. Flopped out in a Japanese market, the best specimens of the sleek fish, which grow up to 15 feet long, can fetch $100,000 or more.