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PHYTOPLANKTON
IN NORTHERN OCEANS HAVE DECLINED FROM 1980s LEVELS
Phytoplankton
Press Release
Introduction
A
check up of the Earth's planetary health reveals that the lowest rung in the ocean
food chain is shrinking. For the past 20 years (early 1980s to present), phytoplankton
concentrations declined as much as 30 percent in northern oceans. Scientists from
NASA and the National Oceanic and Atmospheric Administration (NOAA) say warmer
ocean temperatures and low winds may be depriving the tiny ocean plants of necessary
nutrients. However, they still do not know if the loss of phytoplankton is a long-term
trend or a climate oscillation. Earth's
Checkup
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| | | Image
1 | | |
Scientist
can monitor ocean and planetary health through phytoplankton. Since the whole
ocean food chain depends on the health and productivity of phytoplankton, a significant
change could indicate a shift in our climate. Phytoplankton consists of many diverse
species of microscopic free-floating ocean plants that form the base of the ocean's
food chain. These plants thrive on sunlight and nutrients. Limit either one and
phytoplankton will not grow. This image from the SeaWiFS instrument on board the
Orbview-2 satellite shows the green clouds of phytoplankton pulsating around the
globe. Yellows and reds represent high concentrations of phytoplankton. Summer
Phytoplankton Around the World
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| | | Image
2 | | | Phytoplankton
concentrations have declined substantially in northern oceans since the early
1980s. This world map compares satellite data collected during the summer(July-September)
between 1979 and 1986 and 1997 to 2000 and reflects the changes in phytoplankton
concentrations over the last 20 years in the open ocean (away from the coast).
Deep blues show the greatest loss of phytoplankton, yellow represents almost no
change and browns, reds and oranges show phytoplankton increases. Black indicates
that no data is available.
Summer Phytoplankton in the North Pacific
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| | | Image
3 | | | The
largest phytoplankton decline was in the North Pacific where concentrations have
dropped by 30 percent since the 1980s. This image shows a close-up of the north
Pacific. While there is some red in this image representing a slight increase
in phytoplankton, it is not enough to make up for large decreases in the blue
areas. The data was collected in the summers (July-September) from 1979-2000.
Summer Phytoplankton in the North Atlantic
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| | | Image
4 | | | In
the North Atlantic, phytoplankton concentrations have dropped by 14 percent since
the 1980s. Like the North Pacific, there is a lot of red representing a slight
increase in phytoplankton but it does not make up for the large decreases shown
in blue. The data was collected in the summers (July-September) from 1979-2000.
 Color
bar for Images 2-4 Click
on bar to enlarge Summer
Phytoplankton 1979 to 1986
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| | | Image
5 | | | This
image shows summer (July-September) phytoplankton concentrations from 1979 to
1986. This data set was collected by the Coastal Zone Color Scanner (CZCS) on
board the Nimbus 7 spacecraft with additional sampling from ships and buoys in
the ocean. CZCS is a predecessor to SeaWiFS and was designed to monitor ocean
color. Ocean color reflects varying concentrations of phytoplankton that absorb
different levels of sunlight. Reds show high concentrations of phytoplankton,
yellow represents medium concentrations, green is the next rung down and blue
is low. | | |
North
Pacific, Summer, 1979-1986 | North
Atlantic, Summer, 1979-1986 |
Summer
Phytoplankton 1997 to 2000
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| | | Image
6 | | | This
image shows summer phytoplankton concentrations from Sea-viewing Wide Field-of-view
Sensor's (SeaWiFS) launch in 1997 through 2000. SeaWiFS data is establishing a
solid baseline for scientists to monitor the impact on phytoplankton of global
climate change. Reds show high concentrations of phytoplankton, yellow represents
medium concentrations, green is the next rung down and blue is low. | | | North
Pacific, Summer 1997-2000 | North
Atlantic, Summer 1997-2000 |

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