Sea floor scourer: Sculptured iceberg in North Bay, Rothera Point, Adelaide Island, Antarctica.
Credit: Pete Bucktrout/British Antarctic Survey
Effect on sea life
On a local scale, ice scour eliminates populations of sea spiders, sea urchins and other benthic (sea floor) marine life. But on a regional scale it clears a space for marine life to grow, much like a large tree falling in the rainforest leaves room for new tree growth. Too much disturbance, however, could tip the balance and reduce diversity, the researchers say.
Previous research led by Smale, published in the journal Marine Ecology Progress Series in November last year, showed fewer species, fewer individuals and less of the seabed colonised where increased ice scouring had taken place.
Robin Beaman, marine geologist with the Collaborative East Antarctica Marine Census (CEAMARC), which surveyed the Antarctic seabed in December 2007, said the research was interesting and could be a good test of the ecological theory known as the 'intermediate disturbance hypothesis'. The hypothesis states that low diversity is a characteristic of both dynamic environments, where animals are eliminated by disturbance, and stable environments, which allow animals to out-compete each other.
"More ice scouring could suppress the life on the Antarctic sea bed. You literally bulldoze the environment into nothingness," said Beaman, who is based at James Cook University in Cairns, Australia.
