The smallest sea turtle
India has five kinds of marine turtles of which the most common and the smallest is the Olive Ridley turtle. As the name indicates, this turtle is olive green in colour. It has paddle shaped limbs that help it to swim in the oceans where it spends its life. Unlike the tortoises, the marine turtles cannot retract their heads and limbs into the shell. Olive Ridleys are often found near the mouths of rivers, in mangrove forests with low salinity waters. They are also seen in open oceans. In fact, they seem to travel very long distances to reach our shores.
The Olive Ridley nests all along the East Coast of India, from the Sunderbans to the Gulf of Mannar. A unique phenomenon occurs at the Gahirmatha beach at Orissa, when thousands of female turtles arrive in a single night to lay eggs. After filling the nest hole, the turtle smooths sand over it. It has also been known to cover its nest with vegetation growing nearby, usually a kind of creeper or grass. Olive Ridleys are omnivorous, feeding on fish, crabs and other shelled sea creatures.
Four other kinds of marine turtles are found in the seas around India. They are the Green turtle whose meat is popular and which is an ingredient of turtle soup; the Hawksbill turtle whose shell is coveted and highly priced; the Loggerhead turtle which has an enormous head and extremely strong beak and fins; and the Leatherback turtle which has a leathery, rather than a horny covering and is a strong swimmer.
The mangroves
Along the sandy and rocky shores of the mouths of rivers and muddy seashores, places where any other tree would perish as a seedling, lives and grows a special group of trees-the mangroves. There are many species of mangroves. They all have one common property- their tolerance to salt. What makes these trees salt resistant? Some mangroves take in sea water, extract the salt with special glands and then secrete it from their leaves. Others have roots that filter out much of the salt even as it enters the tree. The remaining salt is stored in the oldest leaves of the tree- those that are about to fall. Thus the salt does little harm.
Mangrove trees have to adapt not only to living in salty water, but also to growing in the continuously shifting sandy soil which gives little scope for the trees to get a firm hold. Mangroves anchor themselves to the soil by sending out long roots from their trunks and branches. These stilt roots support the tree and prevent it from toppling over. The muddy waters where they live contain very little oxygen. But mangroves have and ingenious solution to this problem too. The trees send out a second air-breathing root system, not downwards but popping up above the mud-like the snorkel of a diver.
In addition to the props that come down and roots that shoot up, mangroves have roots that trap the silt and debris from the sea as well as the trees' own fallen leaves. In course of time, this accumulation helps to create more land area around the trees, and a new habitat is created. Mangroves growing together create an entire ecological complex along some parts of our coast. These are also called mangals in India. Mangrove swamps perform a very important function-they nurture the seas and protect the land.
They help control floods by catching and spreading high velocity flood waters. They catch the fertile silt flowing away to the ocean with the rainwater, and trap it amongst their roots. Mangrove swamps provide vital breeding grounds and habitats for a great variety of shellfish. The nutrient rich soil provides food and shelter to innumerable organisms. The fallen leaves provide shelter to tiny shelled creatures. Floating mangrove leaves provide a base for larval growth and for micro fauna. The rotting fallen leaves of the trees provide food to insects, reptiles and shellfish. The smaller animals form food for the larger creatures that live or pass through the swamps. Many fish-eating birds come here for the abundant food and the shelter. It is a world teeming with life.
India has about 3,150 kilometers of mangrove cover. Our mangrove swamps or mangals have around 50 species of mangrove trees. The mangroves along our eastern coast are thicker when compared with those on the western coast. The best mangrove formation in India occurs in the Sundarbans in the Bay of Bengal, and in the Andaman and Nicobar islands. The Sunderbans has been designated a world heritage site- one of the natural wonders of the world.
All over the world mangroves are being degraded at an alarming rate. There are several reasons for this. There is a tremendous pressure on areas where they grow due to increasing industrialisation. Mangroves are exploited directly or indirectly, for food, duel, timber, medicines and fisheries. In India also, our mangroves are under threat. The trees are used as timber, firewood, charcoal and as a source of tannin. Honey is harvested in large quantities. Mangals have also been converted into salt pans. In the last 200 years, the area under the Sundarbans mangroves have been reduced to one third of its original size. These pressures are destroying unique ecosystems.
The Bengal Tiger
Among the tangled roots and the salty waters of the Sundarbans mangroves lives the Royal Bengal tiger. Great indeed is the adaptability of this majestic beast. For the tiger is equally at home in sweltering thick evergreen forest, arid tall grasses of dry lands, the heights of cold mountains and even in the swamps of the Sundarbans. Wherever it roams, the tiger needs three conditions for survival: vegetative cover, water supply and sufficient prey- be it deer, antelope, wild buffalo, porcupines, and even peafowl. It ma also prey upon domesticated cattle if it is hunting near human habitation.
The tiger hunts by stalking its prey. That is, it moves silently, hidden until it approaches close to its prey from behind. At an appropriate time, it lunges on the prey, knocking it down through sheer force, and then sinks its claws and teeth into the neck of the victim. It generally drags the kill to a secluded placeto eat. The hunt is neat and efficient. The tiger does not kill unless it is hungry. The tiger is a loner. It usually lives and hunts alone, except when it is courting, or when a tigress is with its cubs. Cubs stay with the mother till they are two years old. The tigress protects them and trains them to stalk and hunt.
The tiger has always been held in awe for its regal and majestic appearance. It has been used to symbolise power and strength. It is this very majesty that has proved its greatest undoing. For hundreds of years it has been hunted as a grand trophy. Hunting is now banned ut the treat continues from poachers who kill it for its skin, claws and bones which fetch extremely high prices in illegal markets. So grave is this danger that in the 1970s, this grand beast that once numbered 40,000 in India was on the brink of extinction. A big project titled Project Tiger, was initiated to ensure that this did not happen. The only way the tiger can be saved is by ensuring a healthy habitat, for not only the tiger, but for all the plants and animals that share it.