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Earth's oceans are wide-reaching and

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teeming with life

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one microscopic aquatic organism plays a

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major role in making life on Earth

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possible phytoplankton if it weren't for

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phytoplankton the earth as we know it

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would probably not be able to exist life

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on this planet pretty much depends upon

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phytoplankton light and the presence of

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nutrients in the surface waters make

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phytoplankton growth possible physical

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processes like ocean circulation and

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upwelling help to regulate the

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distribution and abundance of the plants

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for the last decade scientists have used

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satellite measurements of ocean color to

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determine the global distribution of

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phytoplankton and to begin to link its

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variability to environmental factors the

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beauty of studying the oceans from space

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in a consistent way that satellites

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allow us to do is that you can study

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phenomena both on different time and

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different space scales using data from

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an instrument called seawifs researchers

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observe that both natural and

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human-induced events caused levels of

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phytoplankton to shift from their usual

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rhythms under certain conditions

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excessive phytoplankton growth can

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result in an area known as a dead zone

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dead zones form when big blooms of

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phytoplankton at the surface trigger

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large quantities of organic matter which

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then sink to the bottom

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bacteria break down the organic material

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releasing carbon dioxide but absorbing

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oxygen as they work most marine

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organisms need oxygen for survival and

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dead zones prove fatal for many aquatic

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species

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many human activities on land trigger

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the seasonal appearance of dead stones

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fertilizers runoff lawns and farmland

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they seep into the network of rivers and

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streams that comprise a local watershed

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and provide a jolt of nutrients to

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phytoplankton that edge the shore the

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Mississippi River watershed drains

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directly into the Gulf of Mexico where

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dead zones frequently occur satellites

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cannot actually see dead zones but they

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can monitor the distribution and

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abundance of phytoplankton including

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conditions that may lead to phenomena

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like dead zones there is no question

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that the earth is changing in the

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decades since its launch seawifs has

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enabled us for the first time to monitor

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the biological consequences of that

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change to see how human activity and how