May 8, 2013

Scientists with the Arctic Monitoring and Assessment Programme held a conference in Bergen, Norway, on May 6-8, at which they discussed their findings on the increasing acidity of the Arctic Ocean. The cause of increasing acid levels in seawater worldwide is higher levels of carbon dioxide (CO2) in the atmosphere. In addition to increasing Earth’s temperature, atmospheric carbon dioxide is also absorbed into the sea water.  This effect slows global warming.  The chemical reaction, however, causes the water to become more acidic. The surface waters of oceans worldwide have become 30 percent more acidic since the Industrial Revolution in the mid-1800′s owing to this phenomenon.

The Arctic Ocean is rapidly becoming much more acidic because of increasing levels of carbon dioxide in the atmosphere. (© Corbis/SuperStock)

The Arctic Ocean is particularly sensitive to this process. That ocean is fed by many rivers and by melting ice. The amount of freshwater, that is, not saltwater, in the Arctic Ocean aids the process of acidification.  The cold temperature of the Arctic Ocean also makes it more vulnerable to increasing acidity.

Scientists believe this growing acidity will have a great effect on Arctic ecosystems, but they are not sure what that effect might be. Studies do indicate that many animals grow more slowly in more acidic water and shell-formation is affected in mollusks.  On the other hand, sea grasses thrive in more acidic water. It is the Arctic’s valuable fish—Arctic cod, for example, which is a food source for humans and marine mammals—that scientists are uncertain about.  More studies need to be undertaken to ascertain how Arctic fish will fare in their changing environment.

This change in the pH level of the Arctic Ocean comes at a time when the area is experiencing other great environmental changes: rising temperatures and diminishing sea ice. It is difficult for scientists to predict what the net effect of these climate-change induced alterations will be.

Other World Book articles:

• Arctic
• The Ocean’s Changing Chemistry: Tipping the Balance? (a special report)

Other websites of interest:

• Arctic Monitoring and Assessment Programme

February 19, 2013

Scientists announced this week that for the first time they had found living bacteria beneath a glacier in Antarctica. A team of scientists from the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD), funded by the U.S. National Science Foundation, made the find. The bacteria were discovered in Lake Whillans, which is about one-half mile (800 meters) below the West Antarctic Ice Sheet. The lake is about 5-feet (1.5-meters) deep, and scientists had to drill through the entire half mile of ice to take a sample of the lake water. After running a culture of the sample, they were able to see the bacteria under a microscope. The bacteria are members of a new ecosystem of living things that is able to survive with little light, at very cold temperatures, and under large amounts of pressure.

Lake Whillans sits at the upper tip of the Ross Ice Shelf in West Antarctica. (World Book map; map data © MapQuest.com, Inc.)

DNA testing is required for scientists to be able to identify the bacteria. Once identification has occurred, it might give scientists a better idea of what the bacteria use as food.

In addition to the excitement of finding life under Antarctic ice, scientists were also very interested in the bacteria because the conditions in Lake Whillan are not unlike some of the terrains found in outer space. For example, Jupiter’s moon, Europa, and Saturn’s moon, Enceladus, both have water that exists under ice. If the bacteria discovered under Antarctica is, for example, found to consume minerals from surrounding rock as food, a similar lifeform might be able to exist elsewhere in the solar system.

Additional World Book articles:

• Jupiter
• Europa
• Saturn
• Enceladus