Major ecosystem shift in Arctic seas
Bering Sea at sunrise. Listen to a 9-minute podcast with Jackie Grebmeier from the new Earth & Sky Clear Voices podcast series. (Photo by ra64)
In Earth’s warming north polar region, entire ecosystems are moving north.
That’s according to Jackie Grebmeier, a scientist from the University of Tennessee at Knoxville. She is lead author on a study of the Northern Bering Sea, between Alaska and Siberia. Grebmeier told Earth & Sky that, over the past decade, ice in this northern sea has retreated earlier in spring and refrozen later in fall.
Clams form the base of the food chain in this region. As the cycle of ice melting and refreezing changes, less food for the clams is produced, and their population shrinks. Other species of clams move in. As a result, threatened sea ducks that feed on the clams are finding it difficult to survive.
Jackie Grebmeier: The other clams that are coming in are thicker shelled and have less meat. So basically, the birds are getting less bang for their buck. They have to dive, they have to expend so much energy, but what they’re bringing back for their net carbon is less.
Gray whales have changed their yearly migration patterns in this region, too. They’ve moved north into shared feeding grounds with other whale species, crowding them. Grebmeier said she expects populations of ice–adapted mammals – like walrus and polar bears – to decline.
She said she’s not yet able to predict a timeline.
Our thanks today to NOAA, the National Oceanic and Atmospheric Administration.
Jackie Grebmeier added: “I would say that we are seeing more of the warming in the polar regions, with the caveat of variability. And that’s one of the things about system changes: you tend to get more variability before you get to another state.”
“The polar regions are kind of the first indicators of what is happening as far as the warming, but I think the weather patterns and the differences we’re seeing around the world are ramifications of that.”
Additional Arctic research from the University of Tennessee
Western Arctic Shelf–Basin Interactions Project
NOAA’s Arctic Change Indicator Website
Our thanks to:
Jackie Grebmeier
Research Professor and Project Director
Dept. of Ecology & Evolutionary Biology
Marine Biogeochemistry and Ecology Group
University of Tennessee at Knoxville
doom doom doom !here in florida this very last month we had record cold temperatures i believe some study should be made that heat is not an effect of global warming but our temps are an effect of global cooling. and if you read an actual textbook on temp shifts you will find that a rise in co emmissions preceed an ice age. i want a study on violence in our society and how it can be traced to popular music, video games, and movie violence!
Ummmm… sam, i believe that the rate at which the CO2 in our atmosphere has been increasing is pretty much unprecedented. the increases that may have preceded any ice ages were most likely slow and natural, not caused at an extreme exponential rate like we have seen since the industrial revolution. i personally cannot believe that it is a coincidence that this increase began naturally right around the time that we humans began pouring emissions (including CO2) into the atmosphere. scientists are well aware that “global warming” will cause erratic weather patterns, including record cold temperatures in florida. [note Jackie Grebmeier’s comments above, which I just noticed :-) ] if you lived in a colder climate, you would probably have more opportunity to notice that frequent and severe weather shifts have been occuring over the past few years. here in Pennsylvania, we have had temperature changes of 30-50 degrees over the course of 24 hours multiple times already this year. that is an effect of global warming.
if you purchase a used college textbook on geology or any of the earth sciences you will find that changes in co levels are not in fact unprecedented. instead you will find that cycles both gradual and abrupt are not new. before we jump on the media bandwagon that the sky is falling we should personally endevor to seek the truth and i speak not of the truth as according to brittany spears. just the other day i saw rosie odonell state thet the twin towers collapse was a hoax. in her words she stated thiat it was phsicly impossible for fire to melt steel. if you check with a fireman you will find that not only is it possible but that they are trained for this thru their career. you will also find that not only is steel not a product of fairy dust but that celebrities should stick to entertaing us. this could very well be either politically motivated (see al gore who was vice president for 8 years) who had our attention but did not realise he could speak of this disaster, but also see that mainstream actuall climatologists are not running thru the streets yelling the sky is falling.this issue is worthy of study but not scare tactcs and panic.
Let me rephrase… unprecedented when compared to gradual changes of the past. Of course there have been abrupt CO2 increases in the past… due to cataclysmic events. i was not trying to say that there have never been changes in CO2 levels before. look, i am not an expert on climate change. i studied environmental engineering, and have read a good bit of scientific information about research on the topic. i probably know more about it than 90% of the population (at least), but i am still not an expert because i don’t devote every waking hour to studying climate change. i guess the only point i am trying to make is that humans are adversely affecting the Earth’s ecosystems and climate, and that those of us who understand this have a responsibility to try to make others aware of it too. i would have to agree that celebrities like Rosie O’Donnell probably don’t have much of a clue when it comes to science, but some are actually well read and are simply trying to use their fame to draw attention to the fact that we are causing more harm than is necessary. and i really can’t see how what Al Gore has done is politically motivated…perhaps if he was running for president that would make sense, but he’s not. i would be open to hearing an explanation of how Al Gore’s activism and “An Inconvenient Truth” (which I haven’t even seen) was/is politically motivated. I’m not saying it wasn’t in some way, but i just can’t see how it was right now. a person can’t expect this site to ignore the negative effects our collective actions are having on the Earth just because they don’t want to have to hear about it. these are also stories about science. i look at it as motivation to do more every time i read a story on the subject. more and more people are beginning to realize what is going on because of reports like this one. plenty of climatolgists are saying that we need to change our ways… why do people have such a hard time accepting that our current way of life may not be the best way?