Research scientist James McClintock was on the ice one day in Antarctica, peering into the water through a dive hole, when he noticed an odd sight.
"I saw a little shrimp swim by in the dive hole, and it was holding and carrying a little sea butterfly on its back. I thought to myself, 'Why in the world is this shrimp going to all the trouble to capture and carry a sea butterfly?'"
McClintock, a renowned Antarctic climate and chemical ecology expert from the University of Alabama at Birmingham, told a room full of local students at the Tennessee Aquarium on Friday that the sea butterfly, like many sea creatures at the earth's bottom, has developed chemical defenses against being eaten -- and shrimp know it.
A sea butterfly actually is a snail with frilly edges. The frigid water discourages the development of hard shells, so the sea butterfly's chemical defense is a bad taste, McClintock said. Fish that try to eat a sea butterfly spit it back out.
"We began looking and saw many more shrimp carrying sea butterflies," he said. "We caught some shrimp and found that most of them were carrying the sea butterflies. ... We offered a fish a shrimp with a sea butterfly on it back, and the fish spit them both out. And the shrimp happily swam away."
McClintock's shrimp-and-sea-butterfly research was published in Nature magazine in 1990. The work set him on track for a lifetime of researching chemical ecology for medicine.
His research from 13 two-month missions to Antarctica has contributed to ongoing research on an H1N1 flu preventive patch, a possible skin cancer cure and medication for cystic fibrosis.
On Friday, the stories of his research fanned what McClintock called the "excitement of discovery" for about 200 high school students from Tyner, Baylor, Girls Preparatory and McCallie schools.
Aquarium spokesman Thom Benson said the researcher helped students see how new chapters in marine biology are being written. But Benson said McClintock's message does more.
"When people have an opportunity to meet a researcher like Dr. McClintock, they get an unbiased, scientific view of how climate change is impacting wildlife and what may be at stake for all of us," Benson said.
McClintock said his work has raised his concerns about climate change.
"We could lose species. We could lose a cure for cancer," he said.
Ten years ago from his office at Palmer Research station, he and co-workers would hear the sound of ice breaking away from the Antarctica ice shelf about once a week.
"That would send us all running to the window to look," he said. "But last year, we would hear them crashing about five times a day. We're talking ice sheets, some the size of Connecticut, breaking off of Antarctica."
As temperatures rise, so does the humidity, he said, and humidity means more snow.
Adélie penguins, the "Happy Feet" penguins, are hardwired to lay their eggs at the same time each year. These days, that time of year also is one of heavy snow. As the snow melts, the eggs drown.
And as the Antarctic ice shelf recedes, the surviving penguins must use valuable energy to swim farther and farther away from their nesting ground for food.
"We used to see 15,000 breeding pairs near our station. Now they are down to 3,000 breeding pairs," he said.
Another climate-change phenomenon is the advance of king crabs up onto the Antarctic shelf from the warmer depths of the ocean, he said.
King crabs, with their crusher claws, have never before been a threat to the shell-less and soft-shelled creatures of the Antarctic because the cold water near the surface once kept the crabs away,
Although the crabs are not at the same level as the other creatures yet, he said, they are getting closer, and the soft-shell coral and other animals may not be able to adapt as quickly as necessary to avoid being eaten.
"Over millenniums (of normal cyclical climate change), organisms have the opportunity to adapt, but this is happening over decades, not millenniums," he said.
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