JACOB KONST/Arizona Daily Wildcat Geosciences professor Karl Flessa, aside from teaching courses in paleontology and oceanography, researches skeletal remains of marine mammals and fish from the Colorado River to learn about past ecosystems.

You can learn a lot from a mollusk. In fact, scientists like Karl Flessa have shown how mollusk remains unlock certain mysteries of past ecosystems.

Flessa is a professor of geosciences in the College of Science, where he teaches introductory courses in paleontology and oceanography, and also serves as an adviser to undergraduate and graduate students in the program.

Part of Flessa's research involves the study of clamshells, snail shells, bones of marine mammals and fish ear bones to determine what life was like in the Colorado River delta decades ago.

"We're putting the dead to work," Flessa said.

He said skeletal remains not only point to the different species that existed in the region during a particular time period, but also how scientists can study their features to measure environmental change over time.

Flessa said, for example, water temperature can be determined by analyzing the geochemistry of shell layers.

The process takes a certain amount of detective work.

"In a sense, it's forensic science," Flessa said.

He said studying the remains of marine life also helps scientists devise guidelines for the restoration of habitats that once existed in the Colorado River delta.

Flessa said there is a growing movement among environmental policy analysts to assign dollar values to ecosystems to determine the economic value of such areas as the Colorado River delta.

"In an economic sense, nature subsidizes a lot of human activity," Flessa said.

He said it is important to determine how much the water is worth in terms of the ecosystems it supports.

The Colorado River alone provides water for millions of people in cities throughout the Southwest, including Los Angeles, Las Vegas, Phoenix and Tucson.

Flessa said people who reside in these areas should be open to the idea of paying a few extra pennies in their water bill each month to support the preservation of ecosystems in and around the river.

He said this concept is gaining ground in environmental policy circles.

Flessa was born in Germany, but his family immigrated to the United States when he was a child, settling in Cheshire, Conn.

He said was always attracted to the features of the natural world, but it wasn't until he took a geology class as a college student that he realized he should pursue a career in geosciences.

Flessa earned a bachelor of arts degree in geology from Lafayette College in Pennsylvania, followed by a Ph.D. in geology from Brown University in Rhode Island.

His first job out of graduate school was at SUNY-Stony Brook, on the north shore of Long Island.

In 1977, he was offered a position at the UA, where he has remained.

Flessa said he has enjoyed his years teaching and conducting research at the UA.

"There's a tremendous amount of interdisciplinary freedom at this university," he said.

Flessa said he has benefited from learning how to bring the scholarship from other disciplines, such as biology, history, economics and law, to bear on important projects in his own field of study.

Flessa said he also enjoys having the opportunity to work closely with students in the geosciences program.

"Students are a really important part of my research," he said.

Flessa said he hopes students come away from his classes with the ability to find and evaluate scientific information so they can make intelligent decisions about their lives.

"We're faced with a lot of decisions that require scientific insight," he said, referring to such current debates as health care and the environment.

Flessa's students said they appreciate being able to apply what he has taught over the semester.

Bryant Smith, a pre-business sophomore in Flessa's oceanography class, GEOS 212, just returned from the class field trip to Rocky Point, although Flessa did not attend because the other oceanography professor, George Gehrels, organizes and chaperones the trip every semester.

"All the stuff we've learned in class we applied down there," Smith said.

Other students emphasize how he uses the techniques of paleontology and applies them to modern conservation practices.

"He's trying to make science work for society as a whole," said Ta-Shana Taylor, a fourth-year geosciences graduate student.

"His research affects so many people," Taylor said.

Taylor said Flessa only takes on students he really believes in, and he also supports women and minorities in science, pointing out how people from diverse backgrounds bring different insight and experiences to bear on her discipline.

"He's changing the face of science," Taylor said.