A new study has found
that the Bering Sea ecosystem is responding
to changes in arctic climate and the effects
could extend from base of food chain to
native hunters. 13/03/2006 - Physical changes--including
rising air and seawater temperatures and
decreasing seasonal ice cover--appear to
be the cause of a series of biological changes
in the northern Bering Sea ecosystem that
could have long-range and irreversible effects
on the animals that live there and on the
people who depend on them for their livelihoods.
In a paper published March 10 in the journal
Science, a team of US and Canadian researchers
use data from long-term observations of
physical properties and biological communities
to conclude that previously documented physical
changes in the Arctic in recent years are
profoundly affecting arctic life.
The northern Bering Sea provides critical
habitat for large populations of sea ducks,
gray whales, bearded seals and walruses,
all of which depend on small bottom-dwelling
creatures for sustenance. These bottom-dwellers,
in turn, are accustomed to colder water
temperatures and long periods of extensive
sea ice cover.
However, "a change from arctic to
sub-arctic conditions is under way in the
northern Bering Sea," according to
the researchers, and is causing a shift
toward conditions favouring both water-column
and bottom-feeding fish and other animals
that until now have stayed in more southerly,
warmer sea waters.
As a result, the ranges of region's typical
inhabitants can be expected to move northward
and away from the small, isolated Native
communities on the Bering Sea coast that
subsist on the animals.
Jackie Grebmeier, a researcher at the University
of Tennessee and one of the paper's co-authors,
said:
"We're seeing that a change in the
physical conditions is driving a change
in the ecosystems."
Grebmeier said the new report is unusual
in that it looks at the potential effects
of a changing climate in the Arctic primarily
through a life-sciences lens, rather than
an analysis of the physics of climate change.
"It's a biology driven, integrated
look at what's going," Grebmeier said.
Grebmeier is chief scientist for the Western
Shelf-Basin Interactions (SBI) research
project, which conducted a series of research
cruises to observe changes in the carbon
balance of the offshore areas of the Alaskan
Arctic and their effects on the food chain.
The cruises included a number of researchers
supported by the US National Science Foundation
(NSF), the US National Oceanic and Atmospheric
Administration (NOAA), and other US federal
agencies.
NSF and the Office of Naval Research (ONR)
jointly funded SBI.
