Boris Sirenko and Sergei Gagayev spent much of a recent voyage through Arctic waters leaning over the starboard side of their research ship, dredging the sea floor for crustaceans.
The so-called graceful decorator crab, or Oregonia gracilis, had never been found anywhere near this cold northern water. "It's real evidence of warming - maybe," Sirenko said in his cabin aboard the Professor Khromov research vessel.
The duo were part of a rare joint U.S.-Russian expedition through the western Arctic to study the impact of global warming in the only region where the two nations share a border.
But it could be years before the biological, physical and chemical data are pieced together to form an accurate picture.
The narrow Bering Strait between Russia and Alaska is the only gateway where Pacific Ocean waters flow into the Arctic.
Scientists are worried about dramatic loss of ice cover in the last quarter century and suspect changing climate and atmospheric pressure as well as warm ocean currents moving further north are to blame.
Using satellite images, recent NASA-funded research has shown that Arctic sea ice that lasts through the summer is shrinking by 9 percent a decade, reaching a low in 2002.
This has major implications for the rest of the world as sea levels rise with the melting of glaciers on land and coastlines erode. In the Arctic, some stocks of fish and other marine life have diminished, possibly due to the changes.
Governments are agonizing over how to cut emissions of greenhouse gases like carbon dioxide from the burning of fossil fuels, thought to be speeding the warming.
But here, where even in late summer the sky stays light for nearly 24 hours a day, distrust between Russia and the United States long kept exploration to a minimum.
EXPLORATION HAS LAGGED
Hence the expedition, arranged by the U.S. National Oceanic and Atmospheric Administration and Russian Academy of Sciences.
"NOAA is dedicated to setting up observation networks around the world in the oceans, and the Arctic is an area that has been really under-observed in comparison to everything else," said Kathleen Crane, the agency's coordinator on the trip.
There have been studies of the black, churning waters of the western Arctic, but little coordinated research bringing together several disciplines from both countries.
Twenty Russian scientists and 15 from the United States sampled zooplankton, fish and crustaceans at various depths across a huge area of the Bering Strait and Chukchi Sea.
Researchers also ran high-tech pressure, temperature and organic content test of the sea in the first of what is hoped will be a series of studies.
"That's how we set it up - to be able to come back on a regular basis and to monitor and observe over a fairly long period," Crane said as she watched live images of starfish from a remotely operated Russian video camera on the Chukchi seabed.
This is why no one is jumping to conclusions about the crab. Perhaps it existed undiscovered in this under-explored region for a long time, she said.
HIGH SEAS CLIMATE DEBATE
Sirenko, head of marine research at his St. Petersburg institute, is sure that isn't the case. He is skeptical, though, that global warning is a recent phenomenon.
He pointed to a passage from a 1952 Russian textbook describing a warming trend north of the Bering Strait. "It is a usual change of climate with humanity or without humanity," he said.
His view is only part of a huge spectrum of opinion on the hot topic, even among scientific colleagues on the Khromov.
Igor Lavrenov, head of the oceanographic division at the Russian academy's Arctic and Antarctic Research Institute, is convinced of rising average temperatures and changing currents in the last 10 years.
"There are variations, but there is a trend," he said on the deck of the Khromov as it steamed north on a sunny evening. "In the Arctic, the biggest evidence is a reduction in the total average coverage of ice."
Russian scientists and their American counterparts dropped monitoring equipment in western waters of the Bering Strait, which will provide further clues to a high-stakes mystery. It has been a decade since instruments to gauge water temperature and currents were anchored there.
"I believe that the time will be long enough within one year to get some conclusions," Lavrenov said. "But in general, I believe that we will find some differences and the differences will be connected to the climate changing."