27 minutes agoFan worms (turquoise) and sponges (orange) under the sea ice in Antarctica near Casey Station. Credit: Graeme Clark (Phys.org) —Slight changes in the timing of the annual loss of sea-ice in polar regions could have dire consequences for polar ecosystems, by allowing a lot more sunlight to reach the sea floor. The research by scientists at UNSW and the Australian Antarctic Division predicts that biodiversity on some areas of the polar seabed could be reduced by as much as one third within decades, as the poles warm. The study, "Light-driven tipping points in polar ecosystems," will be published in the journal Global Change Biology. Dr Graeme Clark, of the UNSW School of Biological, Earth and Environmental Sciences, says the team's research shows that polar ecosystems may be even more sensitive to climate change than previously thought. "Even a slight shift in the date of the annual sea-ice departure could cause a tipping point, leading to widespread ecosystem shifts. On the Antarctic coast this may cause unique, invertebrate-dominated communities that are adapted to the dark conditions to be replaced by algal beds, which thrive on light, significantly reducing biodiversity," Dr Clark says. The invertebrates lost could include sponges, moss animals, sea squirts and worms. These animals perform important functions such as filtering of water and recycling of nutrients and provide a food source for fish and other creatures. "This is a prime example of the large-scale ecological impacts that humans can impose through global warming – even in places as remote as Antarctica," says UNSW team member, Associate Professor Emma Johnston. "Our modelling shows that recent changes in ice and snow cover at the poles have already transformed the amount of light reaching large areas of the Arctic and Antarctic annually." For the study, the team deployed light meters on the sea floor at seven sites near Casey Station in Antarctica, at depths of up to 10 metres. They used cameras to photograph the coast at midday every day for two and a half years, to determine sea-ice cover. They determined the growth rates of Antarctic algae in the lab in different light conditions, and conducted experiments in Antarctic waters to test the sensitivity of algae to available light. They also surveyed species living on sub-tidal boulders, to see how communities varied with ice cover. Tipping points are events where small changes in environmental conditions cause rapid and extensive ecological change. The amount of sunlight reaching the poles is highly dependent on the seasons because the Earth's tilt causes the sun to be above the horizon for considerably longer during summer than winter, and the lower solar angle during winter increases reflectance from the water surface. "Early melt that brings the date of sea-ice loss closer to midsummer will cause an exponential increase in the amount of sunlight reaching some areas per year," says Dr Clark.
More information: onlinelibrary.wiley.com/doi/10.1111/gcb.12337/abstract Why are natural resources not evenly distributed around the surface? Jul 25, 2013 Is there an exact reason for the non-uniformness or is it all just random?I mean in the early stages of earth's development when It was still hot,...Earth From Space DocumentaryJul 22, 2013 I original posted this in GD. It may be more appreciated here. It is a lot more than just pictures. It is long so get a drink and a some snacks...Why do clouds have flat bottoms?Jul 21, 2013 I know clouds are just condensed water vapor forming tiny droplets. Why do they have flat bottoms and all at the same plane? Is their a air density...NZ EarthquakesJul 21, 2013 hi Gang :) interesting set of earthquakes in the central NZ region in Cook Strait, between the 2 main islands Image:...Smog-Eating SidewalksJul 16, 2013 This is very interesting... The concrete is treated with titanium oxide and absorbs nitrogen oxide from the air. These measurements were taken from a...variation of EM radiation(Sun) in different latitudesJul 06, 2013 So we know that there is variation of EM radiation in different latitudes we receive from Sun. My question is, it same through all EM radiation like...More from Physics Forums - Earth Related StoriesWhy Antarctic sea ice cover has increased under the effects of climate change
The first direct evidence that marked changes to Antarctic sea ice drift have occurred over the last 20 years, in response to changing winds, is published this week in the journal Nature Geoscience. Scient ... Ancient ice melt unearthed in Antarctic mud
Global warming five million years ago may have caused parts of Antarctica's large ice sheets to melt and sea levels to rise by approximately 20 metres, scientists report today in the journal Nature Geoscience. As ice cover disappears, life in the frigid Antarctic moves fast
It might be cold in the Antarctic, but that doesn't mean that life there necessarily moves slowly. A report appearing in Current Biology, a Cell Press publication, on July 11 reveals the discovery of a s ... Antarctic sea ice thickness affects algae populations
In the waters off Antarctica, algae grow and live in the sea ice that surrounds the southern continent-a floating habitat sure to change as the planet warms. As with most aquatic ecosystems, microscopic algae form the base ... Scientists outline long-term sea-level rise in response to warming of planet
A new study estimates that global sea levels will rise about 2.3 meters, or more than seven feet, over the next several thousand years for every degree (Celsius) the planet warms. 1000-year Antarctic Peninsula climate reconstruction provides new insight into accelerating ice melt
A new 1000-year Antarctic Peninsula climate reconstruction shows that summer ice melting has intensified almost ten-fold, and mostly since the mid 20th Century. Summer ice melt affects the stability of Antarctic ... Recommended for youA NASA infrared baby picture of Tropical Depression 7E
Tropical Depression 7E formed in the Eastern Pacific Ocean during the morning of July 30, and a NASA satellite was overhead to get an infrared baby picture. NASA's Aqua satellite passed over the depression ... NASA sees little rainfall in Tropical Depression Flossie
Tropical Storm Flossie weakened as it interacted with the Hawaiian Islands and became a depression. NASA's TRMM satellite saw mostly light rain and one isolated area of heavy rainfall within the storm after ... Satellite shows ex-Tropical Storm Dorian's remnants elongated
Former Tropical Storm Dorian has been hanging around the Caribbean Sea for a couple of days, and appears stretched out on satellite imagery. Cracking how life arose on Earth may help clarify where else it might exist
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A technique for trapping the greenhouse gas carbon dioxide deep underground could at the same be used to release the last fraction of natural gas liquids from ailing reservoirs, thus offsetting some of the environmental impact ... Santa's workshop not flooded—but lots of melting in the Arctic
(Phys.org) —Santa's workshop at the North Pole is not under water, despite recent reports. A dramatic image captured by a University of Washington monitoring buoy reportedly shows a lake at the North Pole. ... User comments : 0More news storiesIs life on Mars related to life on Earth?The idea that there is life on other worlds is humbling and exciting, and finding life on another world would change everything. This has been a driving force for scientists for decades. We find life wherever ... Rare atmospheric phenomenon observedCameras operated by the Armagh Observatory have recorded one of the very few observations from the UK and Ireland of a very rare atmospheric phenomenon known as a 'sprite'. The detection, which was made around ... Could planting trees in the desert mitigate climate change?As the world starts feeling the effects of increasing atmospheric carbon dioxide and consequent global temperature rise, researchers are looking for a Plan B to mitigate climate change. A group of German ... Australia: Greenhouse emissions stable over decade as GDP grew 31%There has been no growth in greenhouse gas emissions in Australia over the last decade, despite economic growth of 31% over the same period, a new report has found. Cracking how life arose on Earth may help clarify where else it might existDoes life exist elsewhere or is our planet unique, making us truly alone in the universe? Much of the work carried out by NASA, together with other research agencies around the world, is aimed at trying ... Field study shows tigers in India follow corridors between groups to maintain gene flow(Phys.org) —A team of researchers working in India has found that tigers living in separate geographic areas mate with tigers from other groups by traversing natural corridors. In their paper published in ... A micro-optical method for thwarting counterfeitingIn order to thwart forgeries, EPFL researchers propose a new miniaturized authentication system. By combining both, moire patterns and microlithography techniques, it can be easily recognized by the naked eye and impossible ... Random, scattered, and ultra tiny: A spectrometer for the futureSometimes a little disorder is precisely what's in order. Taking advantage of the sensitive nature of randomly scattered light, Yale University researchers have developed an ultra-compact, low-cost spectrometer ... Stabilisation of microdroplets using ink jet processProgress means that many things that are used in everyday life are becoming more manageable, practical and generally smaller. This also applies to biological and chemical experiments. To save material and ... A new tool for brain researchPhysicists and neuroscientists from The University of Nottingham and University of Birmingham have unlocked one of the mysteries of the human brain, thanks to new research using functional Magnetic Resonance ... © Phys.org™ 2003-2013  
27 minutes agoFan worms (turquoise) and sponges (orange) under the sea ice in Antarctica near Casey Station. Credit: Graeme Clark (Phys.org) —Slight changes in the timing of the annual loss of sea-ice in polar regions could have dire consequences for polar ecosystems, by allowing a lot more sunlight to reach the sea floor. The research by scientists at UNSW and the Australian Antarctic Division predicts that biodiversity on some areas of the polar seabed could be reduced by as much as one third within decades, as the poles warm. The study, "Light-driven tipping points in polar ecosystems," will be published in the journal Global Change Biology. Dr Graeme Clark, of the UNSW School of Biological, Earth and Environmental Sciences, says the team's research shows that polar ecosystems may be even more sensitive to climate change than previously thought. "Even a slight shift in the date of the annual sea-ice departure could cause a tipping point, leading to widespread ecosystem shifts. On the Antarctic coast this may cause unique, invertebrate-dominated communities that are adapted to the dark conditions to be replaced by algal beds, which thrive on light, significantly reducing biodiversity," Dr Clark says. The invertebrates lost could include sponges, moss animals, sea squirts and worms. These animals perform important functions such as filtering of water and recycling of nutrients and provide a food source for fish and other creatures. "This is a prime example of the large-scale ecological impacts that humans can impose through global warming – even in places as remote as Antarctica," says UNSW team member, Associate Professor Emma Johnston. "Our modelling shows that recent changes in ice and snow cover at the poles have already transformed the amount of light reaching large areas of the Arctic and Antarctic annually." For the study, the team deployed light meters on the sea floor at seven sites near Casey Station in Antarctica, at depths of up to 10 metres. They used cameras to photograph the coast at midday every day for two and a half years, to determine sea-ice cover. They determined the growth rates of Antarctic algae in the lab in different light conditions, and conducted experiments in Antarctic waters to test the sensitivity of algae to available light. They also surveyed species living on sub-tidal boulders, to see how communities varied with ice cover. Tipping points are events where small changes in environmental conditions cause rapid and extensive ecological change. The amount of sunlight reaching the poles is highly dependent on the seasons because the Earth's tilt causes the sun to be above the horizon for considerably longer during summer than winter, and the lower solar angle during winter increases reflectance from the water surface. "Early melt that brings the date of sea-ice loss closer to midsummer will cause an exponential increase in the amount of sunlight reaching some areas per year," says Dr Clark.
More information: onlinelibrary.wiley.com/doi/10.1111/gcb.12337/abstract Why are natural resources not evenly distributed around the surface?Jul 25, 2013Is there an exact reason for the non-uniformness or is it all just random?I mean in the early stages of earth's development when It was still hot,...Earth From Space DocumentaryJul 22, 2013I original posted this in GD. It may be more appreciated here. It is a lot more than just pictures. It is long so get a drink and a some snacks...Why do clouds have flat bottoms?Jul 21, 2013I know clouds are just condensed water vapor forming tiny droplets. Why do they have flat bottoms and all at the same plane? Is their a air density...NZ EarthquakesJul 21, 2013hi Gang :) interesting set of earthquakes in the central NZ region in Cook Strait, between the 2 main islands Image:...Smog-Eating SidewalksJul 16, 2013This is very interesting... The concrete is treated with titanium oxide and absorbs nitrogen oxide from the air. These measurements were taken from a...variation of EM radiation(Sun) in different latitudesJul 06, 2013So we know that there is variation of EM radiation in different latitudes we receive from Sun. My question is, it same through all EM radiation like...More from Physics Forums - Earth Related StoriesWhy Antarctic sea ice cover has increased under the effects of climate change
The first direct evidence that marked changes to Antarctic sea ice drift have occurred over the last 20 years, in response to changing winds, is published this week in the journal Nature Geoscience. Scient ... Ancient ice melt unearthed in Antarctic mud
Global warming five million years ago may have caused parts of Antarctica's large ice sheets to melt and sea levels to rise by approximately 20 metres, scientists report today in the journal Nature Geoscience. As ice cover disappears, life in the frigid Antarctic moves fast
It might be cold in the Antarctic, but that doesn't mean that life there necessarily moves slowly. A report appearing in Current Biology, a Cell Press publication, on July 11 reveals the discovery of a s ... Antarctic sea ice thickness affects algae populations
In the waters off Antarctica, algae grow and live in the sea ice that surrounds the southern continent-a floating habitat sure to change as the planet warms. As with most aquatic ecosystems, microscopic algae form the base ... Scientists outline long-term sea-level rise in response to warming of planet
A new study estimates that global sea levels will rise about 2.3 meters, or more than seven feet, over the next several thousand years for every degree (Celsius) the planet warms. 1000-year Antarctic Peninsula climate reconstruction provides new insight into accelerating ice melt
A new 1000-year Antarctic Peninsula climate reconstruction shows that summer ice melting has intensified almost ten-fold, and mostly since the mid 20th Century. Summer ice melt affects the stability of Antarctic ... Recommended for youA NASA infrared baby picture of Tropical Depression 7E
Tropical Depression 7E formed in the Eastern Pacific Ocean during the morning of July 30, and a NASA satellite was overhead to get an infrared baby picture. NASA's Aqua satellite passed over the depression ... NASA sees little rainfall in Tropical Depression Flossie
Tropical Storm Flossie weakened as it interacted with the Hawaiian Islands and became a depression. NASA's TRMM satellite saw mostly light rain and one isolated area of heavy rainfall within the storm after ... Satellite shows ex-Tropical Storm Dorian's remnants elongated
Former Tropical Storm Dorian has been hanging around the Caribbean Sea for a couple of days, and appears stretched out on satellite imagery. Cracking how life arose on Earth may help clarify where else it might exist
Does life exist elsewhere or is our planet unique, making us truly alone in the universe? Much of the work carried out by NASA, together with other research agencies around the world, is aimed at trying ... Sequestration and fuel reserves
A technique for trapping the greenhouse gas carbon dioxide deep underground could at the same be used to release the last fraction of natural gas liquids from ailing reservoirs, thus offsetting some of the environmental impact ... Santa's workshop not flooded—but lots of melting in the Arctic
(Phys.org) —Santa's workshop at the North Pole is not under water, despite recent reports. A dramatic image captured by a University of Washington monitoring buoy reportedly shows a lake at the North Pole. ... User comments : 0More news storiesIs life on Mars related to life on Earth?The idea that there is life on other worlds is humbling and exciting, and finding life on another world would change everything. This has been a driving force for scientists for decades. We find life wherever ... Rare atmospheric phenomenon observedCameras operated by the Armagh Observatory have recorded one of the very few observations from the UK and Ireland of a very rare atmospheric phenomenon known as a 'sprite'. The detection, which was made around ... Could planting trees in the desert mitigate climate change?As the world starts feeling the effects of increasing atmospheric carbon dioxide and consequent global temperature rise, researchers are looking for a Plan B to mitigate climate change. A group of German ... Australia: Greenhouse emissions stable over decade as GDP grew 31%There has been no growth in greenhouse gas emissions in Australia over the last decade, despite economic growth of 31% over the same period, a new report has found. Cracking how life arose on Earth may help clarify where else it might existDoes life exist elsewhere or is our planet unique, making us truly alone in the universe? Much of the work carried out by NASA, together with other research agencies around the world, is aimed at trying ... Field study shows tigers in India follow corridors between groups to maintain gene flow(Phys.org) —A team of researchers working in India has found that tigers living in separate geographic areas mate with tigers from other groups by traversing natural corridors. In their paper published in ... A micro-optical method for thwarting counterfeitingIn order to thwart forgeries, EPFL researchers propose a new miniaturized authentication system. By combining both, moire patterns and microlithography techniques, it can be easily recognized by the naked eye and impossible ... Random, scattered, and ultra tiny: A spectrometer for the futureSometimes a little disorder is precisely what's in order. Taking advantage of the sensitive nature of randomly scattered light, Yale University researchers have developed an ultra-compact, low-cost spectrometer ... Stabilisation of microdroplets using ink jet processProgress means that many things that are used in everyday life are becoming more manageable, practical and generally smaller. This also applies to biological and chemical experiments. To save material and ... A new tool for brain researchPhysicists and neuroscientists from The University of Nottingham and University of Birmingham have unlocked one of the mysteries of the human brain, thanks to new research using functional Magnetic Resonance ... © Phys.org™ 2003-2013  via Science - Google News http://news.google.com/news/url?sa=t&fd=R&usg=AFQjCNEJ0QdOjy6NCsr_Kc4mgRMH9Z4VXA&url=http://phys.org/news/2013-07-polar-ecosystems-vulnerable-sunlight.html | |||
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