Plankton is vital in the Coral Reef Food WebCORAL REEF FOOD WEB. Plankton, the living soup of creatures that live suspended and drifting with the water, plays a vital role in the coral reef food web and biology of coral reefs. Like cities and even countries, reefs must import food to sustain their dense populations. Feeding on plankton drifting past enables reef creatures to harvest the produce of an area of the sea many times larger than the reef itself. Virtually all of the attached reef animals depend in whole or in part on plankton for sustenance as do the clouds of plankton-feeding fishes that swarm above reefs. Plankton includes a host of diverse organisms ranging from microscopic single-celled bacteria, yeasts, fungi, algae, and protozoan’s through millimetre to centimetre-sized crustaceans, arrow worms, salps and numerous other creatures, to jellyfishes a half-metre or more in diameter. In addition to creatures that spend their entire lives drifting, plankton includes the eggs, larvae and juveniles of both free-swimming pelagic creatures and the denizens of various bottom communities including the reefs themselves. Most reef creatures in fact have planktonic eggs and/or larvae. This method of dispersal underlies both the widespread geographic distribution of most reef organisms and the ability of reefs to rapidly recover their populations when devastated by storms or other disasters. At the bottom line all sustainable systems must balance their books. The harvest of plankton by reefs is balanced by their contribution of eggs, larvae, and organic debris to the water as it leaves them. Energy, ultimately derived from the nuclear incandescence of the sun, is the real harvest in the coral reef food web. The nutrient molecules essential to storing such energy are simply exchanged. Life drifting weightless in a fluid environment without a substrate has afforded plankton the ultimate freedom of design. Some plankters have assumed the shape of spheres, cubes, rectangles, triangles and other geometric forms. Transparency is common. Certain jellyfishes are only slightly less fluid than the water itself. They literally pour into formlessness if lifted from their supporting medium. Feathery appendages and unwieldy spikes and spines are frequent accoutrements. Colonial creatures link up in gossamer chains. The planktonic stages of most bottom dwellers are not simply small versions of the adults, bugs like caterpillar and butterfly, radically and unrecognisably different. Only when they find a suitable substrate and settle down do they transform into a recognisable juvenile version of their parents. Reef creatures feeding on such a diverse food source employ a variety of techniques. Filtering is used by sponges, bivalves, and sea squirts to capture the smallest plankton. Grasping tentacles and tendrils are used by corals, anemones, certain sea cucumbers, and basket starfish for slightly larger plankton. Other related pages:
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