Tuesday, February 27, 2007
Marine Ecosystems Pressured from the Top and Bottom
A study published in the Feb. 23 issue of Science finds that climate change is contributing to ecosystem shifts in in the North Atlantic. Increased flows of cold, fresh water from increased melting of permafrost, snow and ice in the Arctic region are changing the abundances of phytoplankton, zooplankton and fish that live near the ocean's surface. Scientists had attributed these changes to the collapse of cod fisheries from overfishing In places like the Georges Bank off the coast of Massachussetts (shallow area in the NASA image above). The new study suggests that climate change is also playing a strong role.
"It is becoming increasingly clear that Northwest Atlantic ecosystems are being affected by climate forcing from the bottom up and overfishing from the top down," says Charles Greene, a Cornell oceanographer and lead author of the Science paper.