Make your own free website on Tripod.com
Stephen Kingwell
ENDANGERED SPECIES

What are endangered species?

Animals like rabbits and insects like flies are extremely common. They are not in danger of dying out or becoming extinct. Yet other animals and plants species are very rare. Their numbers have been greatly affected by environmental conditions that don't support that particular species' survival in their current habitat. These species are listed by environmental researchers as vary rare. They are placed on a register of "endangered species" in danger of dying out for ever (see an excerpt of this register below).
When did `species' begin to disappear?

Ever since life began there have been endangered species. Throughout geological time, many more species have become extinct than exist today. These species slowly disappeared because of climatic changes and the inability to adapt to such conditions as competition and predation. It is a natural part of evolution. Although the extinction of plants and animals is a natural part of evolution, the number of species dying out per year has risen dramatically since the 1600s. If it continues to increase at the rate at which it is growing now, 50,000 species will become extinct each year by the turn of the century (see table below).


Dinosaurs once ruled the earth, but extinction ended thier future.

Why are there endangered species ?

Habitat DestructionSpecies become extinct or endangered for a number of reasons, but the primary cause is the destruction of habitat. Man has seriously reduced available habitats byDrainage of wetlands conversion of shrub lands to grazing lands cutting and clearing of forests (especially in the Tropics, where the rain forests will be gone by AD 2000 if destruction continues at its present rate) urbanisation and suburbanisation highway and dam construction.As the various habitats become fragmented into "islands," the remaining animal populations crowd into smaller areas, causing further habitat destruction. Species in these small islands lose contact with other populations of their own kind, thereby reducing their genetic variation and making them less adaptable to environmental change. These small populations are highly vulnerable to extinction; for some species, the fragmented habitats become too small to support a viable population.
Hunting for "Food and Fur"

Since the 1600s, commercial exploitation of animals for food and other products has caused many species to become extinct or endangered. For examplethe slaughter of great whales for oil and meatthe African rhinoceros, killed for its horn, the great auk became extinct in the 19th century because of over-hunting the Carolina parakeet perished as a species because of a combination of over-hunting and habitat destruction. Introduced diseases, parasites, and predators against which native flora and fauna have no defenses have also exterminated or greatly reduced some species. The accidental introduction of a blight, for example, eliminated the chestnut tree from North American hardwood forests. Predator and pest control also have adverse effects. Excessive control of prairie dogs, for example, has nearly eliminated one of their natural predators, the black-footed ferret. In Australia the introduction of rabbits and cats has caused the destruction of much of the wildlife. In Queensland the Great Barrier Reef is under serious threat by the Crown of Thorns starfish.


The cutest of creatures, killed for its fur ...

Pollution

Pollution is another important cause of extinctions. Toxic chemicals _especially chlorinated hydrocarbons such as dichloro-diphenyl-trichloroethane (DDT) and polychlorinated biphenyls (PCBs)_have become concentrated in food webs, affecting most strongly those species at the end of the chain. Both DDT and the PCBs, for example, interfere with the calcium metabolism of birds, causing soft-shelled eggs and malformed young. PCBs also impair reproduction in some carnivorous animals. Water pollution and increased water temperatures have wiped out endemic races of fish in several habitats. In Western Australia blue-green algae clogs the Swan and Canning Rivers. This algae thrives because of the amount of garden fertilisers that get washed into the waterways. The algae blocks oxygen supplies reaching the fish in the rivers and their numbers are at great risk.
Unbalanced Food Web

The Food Web set of interconnected food chains by which energy and materials circulate within an ecosystem. These webs are made up of individual food chains. In a grazing web, materials typically pass from plants to plant eaters (herbivores) to flesh eaters (carnivores). In a detrital web, materials pass from plant and animal matter to bacteria and fungi (decomposers), then to detrital feeders (detritivores), and then to their predators (carnivores).If one link in this food chain happens to become extinct there would be an imbalance in the chain. The consequences would be, that those animals that rely on that particular part of the food chain, if they are unable to adapt to knew or different food sources, will die. For example, the Australian Koala can only eat a particular species of gum leaves but habitat destruction has reduced the quality and quantity of those gum trees. The Australian Koala is on the brink of becoming an endangered species.


It wouldn't be Australia without Koala's, but it might have to be

What's being done to help?

Some private and governmental efforts have been mobilised to save declining species. One immediate approach is to protect a species by legislation. Countries all over the world make laws to ensure that there are mechanisms for the conservation of ecosystems on which endangered species depend. In 1972 the Environmental Protection Agency was established in America. Australia has also established agencies through Acts of Parliament (The Endangered Species Act 1992) and the Wildlife Protection Authorityto discouraged the exploitation of endangered species within Australia. It also supports other countries efforts by banning the importation and trade of any product made from such species. Countries have various agreements with other nations_for example, USA with Canada and Mexico for the legal protection of migratory birds.

International efforts center on the Convention on International Trade in Endangered Species of Wild Fauna and Flora, ratified by 51 nations. Its purpose is to restrict exploitation of wildlife and plants by regulating and restricting trade in species. The effectiveness of such laws in various countries, however, depends on enforcement and support by people and the courts. Because of a lack of law enforcement, the willingness of some segments of society to trade in endangered species, and the activities of poachers and dealers who supply the trade, the future of many species is in doubt in spite of legal protection. Australian species of wildlife are in great demand because they are unique, especially bird-life. Recently, in Australia, penalties for trafficking in protected and species have been increased. The court system is committed to strict application of the laws.
What are scientists doing to help?

In an efforts to save endangered species scientists are propagating breeding stock for release in the wild, either to restore a breeding population (as in the case of the peregrine falcon) or to augment a natural population (as in the case of the whooping crane). Due to breeding in captivity, the number of known California condors had risen from 27 in 1987 to 52 by 1992. Researchers are also involved in the determination of critical habitats that must be preserved for endangered species. These habitats may be protected by the establishment of reserves; the value of these may be limited, however, because of the island effect.In Australia environmentalists have lobbied for special locations such as Kakadu National Park to be included in the World Heritage Register in an effort to protect the species that make up this area. Scientists also have an important role in informing the public of the value of many species and the risks of loosing biodeversity through lack of commitment to the environment. In Australia scientists have introduced diseases that only attack pests like rabbits to remove a major enemy of many wildlife species.
Who is Greenpeace



Greenpeace is a privately run and funded worldwide organisation whose sole aim is to bring environmental problems to the attention of the world.Greenpeace has actively campaign against whaling and the killing of animals for their luxury furs. This organisation tries to act as the conscience of the world. It watches how governments and multinational corporations behave towards the environment. For example it has targeted Japanese corporations who still are involved in whaling and African countries who don't put maximum effort in applying the laws against poaching of endangered species.
Endangered Species List (extract only)






REFERENCES