Phytoplankton off the Antarctic Peninsula are responded to climate change in two ways. In the north, the amount of phytoplankton has shrunk because they are pushed to depths where they can not survive.In the south the amount of phytoplankton has increased. There, less sea ice cover lets more sunlight get through, allowing phytoplankton to grow.
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Courtesy of Zina Deretsky / NSF

Warmer Temperatures are Changing Antarctic Phytoplankton
News story originally written on March 16, 2009

The Antarctic Peninsula is warming faster than most other places in the world. Warmer temperatures mean that there is now less sea ice in the nearby Southern Ocean. Plus winds are changing too.

Scientists have discovered that climate change is affecting some of the ocean’s tiniest creatures. These creatures, called phytoplankton, are changing as the area’s sea ice and winds change because of global warming. These single-celled creatures float in ocean water and, through photosynthesis, get their energy from the Sun.

The phytoplankton in the northern and southern areas of the Antarctic Peninsula is not changing in the same way because of global warming. That surprised the scientists.

In the north, there is less sea ice and more wind. This causes the seawater to mix more than it used to. The mixing causes less sunlight that gets through the water. With less sunlight, phytoplankton are doing less photosynthesis.

In the south, sea ice used to cover most of the seawater for most of the year. Now, there is less sea ice. This exposes seawater to sunlight. There is also less wind in the south, so less seawater is mixed than in the north. More sunlight gets through the water. More sunlight leads to more photosynthesis and more phytoplankton.

Last modified May 1, 2009 by Lisa Gardiner.

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