Patrick Crowe, age 10,of San Diego, Calif., for his question:
WHERE IS PLANKTON FOUND?
Wherever there are sizable supplies of water outdoors, there is sure to be plankton. We can search for it in ponds and lakes, streams and rivers, seas and oceans. However, most of its tiny fragments are too small for human eyes to see. So when we find it, we.may be unable to recognize it.
As we know, we share our wondrous world with multitudes of microscopic plants and animals, plus an assortment of bitsy bodies that are neither one nor the other. The most remarkable mixture is the plankton that drifts through our freshwater streams, lakes and salty seas. Though most of its mini members are too small to be seen, it also contains larger creatures that measure an inch or more.
Since most of the world's water belongs in the salty seas, this is where we find most of the plankton.
There it thrives in countless tons, drifting with tides and currents. During the day, the teeming populations tend to sink 100 feet or more below the sunlit surface. At night they rise to the top. Scientists are not sure why or how this amazing operation works.
They know more about why the plankton is thicker in certain areas and also why it multiplies at certain seasons. The mini plants and animals tend to prefer coolish waters, rich in dissolved minerals. Hence the richest plankton supplies are in polar seas and cool ocean currents. Seasonal winds drive back the surface waves and mineral rich water wells up from below. This is when population explosions occur in the thriving plankton.
In places where plankton is plentiful, there are sure to be lots of large and still larger fishes. This is because the remarkable material is a mixture of nourishing seafoods. Directly or indirectly it supplies the.basic food for all the creatures of the hungry sea. And its teeming one cell algae plants produce the oxygen needed by all sea creatures. What's more, much of this plankton produced oxygen escapes into the air. It drifts around the world to supply the land dwellers.
Nobody could list all the different plankton dwellers. Some are so small that they escape through the finest nets. Those large enough to be seen under a microscope look like glassy oddities from alien worlds. These creatures feed on specks of algae. Then they become food for larger creatures.