Icebergs revealed as biological hotbed
3 Oct 2007 by Evoluted New Media
Rather than free-floating frozen voids of life, icebergs are now thought to be biological hot spots, according to a new study.
Rather than free-floating frozen voids of life, icebergs are now thought to be biological hot spots, according to a new study.
Scientists from the Monterey Bay Aquarium Research Institute in California found high concentrations of krill, chlorophyll, and sea birds around the icebergs they studied, supporting the idea that free-floating icebergs continually release micronutrients to the surrounding ecosystems.
“These species are the same that are in the surrounding waters, it’s just a concentration of them around the iceberg because it’s an enriched area,” said lead study author Kenneth Smith, a senior scientist at the Institute.
Smith and his colleagues used satellite images to select the two icebergs in the Weddell Sea - part of the Southern Ocean - in their study and then sailed to the remote targets aboard a research vessel. The icebergs were up to 19km long and more than 37m high and one extended nearly 305m below the sea surface.
They calculated the increase in icebergs has increased biological productivity in the region by nearly 40%. This rise in activity, the researchers add, may play a role in soaking up the carbon dioxide that is causing Earth’s temperature to rise.
Kevin Arrigo, a biological oceanographer at Stanford University in California who led a separate study in 2002, said: “It’s the first time anybody’s actually documented increased biological activity around the icebergs.”
Based on lab work, Smith said the team assumes the meltwater has a large component of iron, which seeds the phytoplankton to grow. Further studies may determine if the concentration of marine life remains in the wake of the icebergs as they drift further out into the oceans around Antarctica.
The study appeared in Science.
