Scientists cruising the Antarctic have often noticed that seabirds like hanging around icebergs. A team from the Monterey Bay Aquarium Research Institute wanted to know why, so in 2005 they sampled water around two massive bergs and found that wherever the ice goes, so does a trail of phytoplankton and krill -- in other words, bird lunch.

That got the scientists thinking: maybe icebergs, as they melt, infuse the surrounding water with iron and other nutrients they picked up before they broke free from land. So on two more recent expeditions, they attacked an iceberg from all sides. They piloted a remote-controlled model airplane to drop GPS trackers onto the iceberg's surface and sent a remotely operated submersible to look for life underneath it. They even deployed sediment traps underwater to catch falling organic material.

The data they collected confirmed their hunch and also showed that the halo of life extends for up to 12 miles. What's more, when the organisms nourished by an iceberg defecate or die, carbon is sequestered in the ocean. That makes the floating ice an important cog in the global carbon cycle -- one that had been overlooked until now, except, of course, by the birds.