Sea, The

hmm on all sides the land is encompassed by the sea off the coast there exists another world another environment to the air-breathing creatures of the land it is a strange world that is rarely entered although from the dawn of history man has used the sea as a rich hunting ground and he has become proficient in the transport of his civilization from one continental island to another but man has even closer ties with the sea but we believe that it was in this favorable environment that life on our planet originated covering three quarters of the earth's surface the vast mass of the sea continues to make life possible for it is the source of all our water and it controls the climate making the earth habitable soaking up energy from the sun stirred by the moon and by the winds the sea is the most powerful force on earth sweeping across the oceans the waves gnaw and gouge the rock that serves as only a temporary buttress for the land constantly it etches new designs in the stone a continual story of erosion but the sea also builds building a sandy beach with the granulated remains of the rocks giving back what it has stolen from the land in small golden change on these sandy beaches there are few animals for there is nothing solid for them to hold on to when the waves come sweeping in the small crustaceans and mollusks that live here have to contend not only with voracious gulls at low tide they also have to face the problem of drying out in the air so they bury themselves in the wet sand or find shallow pools on a rocky coastline the seaweeds and the animals are able to fasten themselves securely to the rocks and so avoid being cast up on the beach or smashed against the stones in the pockets of water left by the retreating tide there is gathered a rich variety of animal life brilliant red sponges beautiful sea anemones in these quiet tidal pools crabs and starfish find havens until the sea returns in the meanwhile their normal pattern of life continues the anemone's flower-like beauty is deceptive a nereid worm caught in the tentacles is injected with poison before being dragged down into the animal sack-like body but there are some creatures of the intertidal zone that can withstand exposure to the air the clams barnacles and limpets that cover the rocks use their shells to prevent their body water from evaporating and they anchor themselves tightly to the rock so that the rushing tide cannot pry them loose the cold fingers of the rising tide creep over the rocks and the intertidal zone will again be covered by the sea living permanently beneath the surface are creatures that do not have to contend with the hazards of tides and surf sitting quietly on the sea floor live the bottom dwelling creatures looking more like plants than animals the sponges lead completely sedentary lives they feed by simply pumping food-laden water in and out of their hollow bodies in a large colony of coral polyps flower worms have made a home in the shallow coastal seas the water is like a rich soup full of microscopic plants and animals the worms have only to stretch out their hairy gills to capture the minute food particles from the water when danger threatens the worms quickly retreat into their tubes barnacles feed in a similar way they've been described as animals that lie on their backs and kick their food into their mouths with their feet surrounded by food locomotion isn't necessary for many bottom dwelling animals they just sit and eat but there are other creatures like the sea urchin and the starfish that need to search out a supply of mollusks however as their prey is anchored to the rock they hardly need to hurry sea slugs crawl over poisonous polyps and even eat them with immunity food and therefore life is so abundant in the shallow waters that living space is crowded a brittle star crawls over a whole colony of polyps in which a red fire sponge has somehow managed to find room and the hermit crab having found an empty shell for its temporary home also has to carry around the anemone that has enveloped the outside of the shell there are some specialized mollusks that propel themselves rapidly over the sea floor they strain the water of food in one area then move off to a new location but most of these bottom dwelling animals are very conservative in their movements and when a sea urchin is pursued by a helmet conch the strange chase has all the qualities of a nightmare swinging from side to side the huge mollusk inches forward on its muscular foot oblivious to the sharp spines the giant snail rears over its victim it will soon cut its way through the shell and get at the urchin soft inner body many of these benthic creatures the bottom dwellers of the seafloor live by scavenging the animal refuse they help to keep the seas clear of dead fish and other decaying matter living in rock crannies the octopus feeds on the crabs and leaves their remains outside its den to be eaten by other scavengers the vicious looking moray eel also lives in rock crevices with its savage jaws and a mottled skin for camouflage the moray is a dangerous adversary but the master of camouflage is the scorpion fish it walks about the sea floor on its pectoral fins then settles down to weight small fishes mistake the tags and tatters of its skin as something edible mistakes of this sort are usually paid for with one's life all these benthic animals that live and die on the bottom have one thing in common they cannot rise above it they are fettered to the ocean floor quite different are the free swimming animals like the shark and the ray the rays which burrow in the sand for clams may feed off the bottom but they have the tremendous advantage of mobility buoyed up by the water they can move through it in any direction and are able to forage for their food over large areas of the sea the free swimming fish are the monarchs of the open waters their successes due to their mobility their keen senses and their relative intelligence here a fish is having its scales cleaned of parasites by one of the smaller brethren even unto the jaws of death the little fish pursue their task an interesting relationship one partner gets the parasites to eat the other has an irritation removed some fishes browse on the algal plants that grow like a furry slime on the rocks but most fish are predators and in this truly three-dimensional world of the waters predators can strike from any angle however there are some inhabitants of the open waters that are well equipped for a defensive existence at the approach of danger the spiny puffer inflates itself its erect quills a formidable deterrent to potential aggressors though not so well endowed the tiny boxer shrimp can nevertheless fend off large fish with its war-like display but most creatures of the sea usually find a crack in the rocks or bury themselves in the sand when not actively engaged in the search for food however there are many predators such as the triggerfish that are not only dangerous they are also intelligent enough to know from experience where to search for prey blowing hard the queen trigger prospects for a possible victim disturbed the crab retaliates violently being careful to evade the powerful claws the trigger will try to bite off the crabs protruding eyes or sever an arm in her strong jaws using her superior mobility to the full able to attack from any direction the fish has a great advantage the crab loses an arm but it still battles on to the inevitable conclusion but there is a beauty in the sea as well as violent death a school of graceful squid hover in the water holding their tentacles so tightly together that they look more like slender beaks these squid and the beautiful marine jellyfish are really living fossils swimming by rhythmic contractions of their cup-shaped bells their ancestors lived and thrived in the warm seas of the pre-cambrian age 600 million years ago 200 million years later large squid-like creatures dominated the seas even today there are squid that are 50 feet long giants that battle the predatory sperm whales half a mile beneath the ocean surface originally creatures of the land the whales invaded the sea some 70 million years ago with their bodies better supported by the water they developed into a massive size blue whales 100 feet long and weighing 150 tons are the most gigantic creatures that have ever lived the dolphins members of the whale family are intelligent social creatures they communicate with each other by squeaks and have complicated brains comparable to man's all these mammals of the sea whether whales or seals are true warm-blooded creatures that breathe air and bear their young alive the world of the sea is an environment that is inextricably linked with the creatures of the land but although man has traveled its surface and suffered the ravages of its storms for centuries fear of the unknown and fear of terrible sea monsters severely discouraged active exploration only in comparatively recent times as man started to scientifically explore the sea oceanographers and marine biologists the scientists of the sea chart the oceanic rivers the currents and study the ocean floor and the plant and animal populations by sending sampling bottles to various depths they can analyze the water for salt content and nutrients biologists determine the distribution and variety of the animals on the ocean's floor by using large dredges sweeping across the bottom they scoop up samples of the life that exists in the deeper waters but these dredging operations however useful are really only a primitive fumbling in the dark to appreciate the problems of deep sea research one must know something of the geography of the sea around the coasts the sea is relatively shallow this is the continental shelf and most of the seeds creatures live in these sunlit waters for it is only in the upper few hundred feet that there is enough sunlight to sustain the plants of the sea beneath the sunlit surface lie the great depths of the ocean a steep plunge of 12 and sometimes eighteen thousand feet down into the dark waters of the abyss although parts of the seafloor are completely flat there is also a rugged submarine terrain of mountain ranges and active volcanoes that tower thousands of feet above the sea floor it is this vast environment that oceanographers are determined to explore with echo sounder dredge even in person to invade these stygian depths man has encased himself in a steel shell the pioneer of deep sea exploration was william bibi but it was left to august picard's bathuscaf to make the ultimate descent seven miles down to the bottom of the mariana trench realizing its great potential the united states navy purchased picard's bathtub to pursue man's personal exploration of the abyss this is a free-floating submersible not tethered by a steel umbilical cord to a mother ship but operating in much the same way as a balloon it uses gasoline for buoyancy and steel shot for ballast the two-man crew work in a steel sphere that is attached to the underneath of the float slowly the intruders leave the sun behind and gradually sink into an uncharted land of perpetual night the sea has been called a silent world but special microphones have now been used to record the weird animal noises that can be heard underwater [Applause] [Applause] hmm without light there can be no plants so the basic food supply of this sunless place consists only of the morsels of dead animals and plants that have drifted down from the surface waters with food at a premium the life of the deep ocean is sparse in this dark void live the strange creatures of the abyss the successful predators of this fringe community have inherited large mouths and needle sharp teeth to seize every possibility for survival life must be a grim struggle for existence in this hostile environment although their appearance is frightful the creatures of the abyss are small only a few inches in length perhaps because of the scarcity of food seen in the dark many of the fish are luminescent their lights are probably used to lure prey within reach of their sharp teeth even in the depths of the ocean the sea is not still for there are changes in density that cause an upwelling of the bottom waters as the water rises to the surface it carries with it the valuable minerals that have settled on the ocean floor these minerals are the essential nutrients for the plants of the ocean the phytoplankton these minute plants drift about with occurrence and are so small that they can only be seen through a microscope but the diatoms single cells only a thousandth of an inch in diameter are nevertheless the basic food supply of the sea on these tiny plants feed the zooplankton minute animals like the copper pot the zooplankton consists of a myriad of microscopic animals tiny squid the larvae of sea urchins and crabs a whole world of small animals and all of them feed on the diatoms and each other the zooplankton in turn are the food for the smaller fish and these food chains continue inexorably for the sea virtually every free swimming animal lives off a creature smaller than itself although most fishes go after their prey with lightning speed some use deception and patient guile to hunt their prey hanging vertically to mimic the nearby finger sponges the trumpet fish drifts slowly towards its victim the creatures of the sea are engaged in a never-ending cycle of eating and being eaten of being hunter and haunted predator and prey in the face of this constant struggle for food one might feel that the animal population would be completely decimated that is until one realizes the massive scale of reproduction in the sea a herring may lay a million eggs at a time a codfish five million of the thick clusters of eggs that are spawned only very few will not be eaten but enough will survive to preserve the species intact birth and death are sometimes intertwined this is the very rare sight of squids during mating the climax results in the parents death and their bodies litter the sea floor with extravagant reproduction balancing the enormous death toll from disease and predators the oceans of the world will continue to provide a rich and almost inexhaustible harvest this world of the sea referred to by the ecologists as the marine biome this rich and varied community of interdependent plants and animals is also a world of great natural beauty but the beauty of nature cannot be based on sentiment animals have essential needs which must be fulfilled if they are to survive the graceful stalking of a crab is in itself a drama that has a certain grim beauty all life is conditioned by the availability of a suitable food supply and the creatures are wonderfully well adapted to their needs the swift graceful movements the keen eyesight the highly evolved nervous system from the eternal night of the deep ocean to the sunlit shallows of the coast the sea unfolds the richest variety of animal life on earth from out of the sea life arose because of the sea the climate on earth is bearable the sea dominates the past and the present and it is the sea that will control the future of all life on earth so you