ATLANTA - The entrance to the world's largest fish tank was turned into an art studio Saturday, and dozens of children took paintbrushes in hand to scrawl aquatic figures next to a giant whale shark that environmental artist Wyland had painted earlier.

"If we're going to have a sea change, an environmental renaissance, you've got to get kids involved," said Wyland, who goes by one name, as the children went to work on a massive mural to be hung at the Georgia Aquarium.

The aquarium was one of the first legs of Wyland's Clean Water Challenge tour, which travels the country with a mobile learning center designed to teach children the importance of water conservation. The goal of the tour is to reduce water waste by 10 million gallons over the next year.

It's the fourth year of the Wyland Foundation's tour, which traveled the East Coast in 2004, the West Coast in 2005 and barged down the Mississippi River last year. This year, the foundation rolls from the Chesapeake Bay to the Rockies, stopping in seven states to paint murals and showcase a mobile classroom that tells the story of a river ecosystem and the impacts of development on local lakes.

Wyland, who estimates he's painted with more than 1 million children in 25 years, said allowing children to help paint murals is a way to connect.

"If we continue to inspire young people, they'll come up with solutions we never thought about," he said.