Ronnie Ballentine, age 11p of Blythewood, s. C:, for his questions
What are pelagic animals?
The words pelagic and archipelago are related and both ire coined from an older name for the sea. Pelagic animals are sea dwellers but because of the vastness of the oceans the experts use the term to describe the creatures that live only in a certain zone the pelagic zone.
Life in the oceans is so different from life on the land that we may find it hard to imagine this watery world. Popeyed fish from the abysmal, depths might be our idea of bug eyed monsters from outer space. Tentacled squids might be imaginary men from Mars.
We become used to the streamlined fish, the lobsters, the clams, oysters and starfish that live in our coastal waters. These waters are shallow, for the sea floor dips down gently as it leaves the land and reaches toward the deep ocean basins. These waters of the continental shelves teem like green meadows with plant and animal life.
Suddenly the shelves end in plunging cliffs, the steep sides of the deep ocean basins. Down here the water is suddenly anywhere from two to seven miles deep. All the sunlight is filtered out below 2000 feet. The miles of water beneath this surface area have existed blacker than blackest midnight since the great oceans were formed.
The pelagic lone is the dimly lighted surface area above the black abyss. These waters teem with pelagic plants and pelagic animals, There are living things deep in the midnight depths. Sometimes, especially at night, countless squid and rainbow colored sea worms come up from the dark depths to feed at the surface. Then they too join the throngs of pelagic animals.
Life in the pelagic zone, like life on the land, follows a food chain. Small creatures feed on plant life, the tang algae and diatoms that throng the sunlit waters. The green sea salad is mixed with shrimps, fish eggs and larvae baby crabs and barnacles. Herring and mackerel comb to feed on the mixed salad. Sharks and tuna come to feed on the herring and mackerel.
The first and most vital link in the chain is the mixture of plants and tiny animals,, a sea salad cabled plankton. This plankton food drifts with the currents and thrives with certain seasons. Bigger animals must go where it goes, In a cup of plankton rich sea water there may be trillions of little animals and an equal number of little plants.
When s marine biologist refers to pelagic animals, he is most likely referring to these little plankton animals. However, larger creatures that live in or merely visit this zone may also be called pelagic animals.