Powered by Blogger.

Monday, March 1, 2010

Wildlife in distress

No comments :
 The wildlife is in distress in the whole world. Besides facing threats from natural calamities, animals are facing additional threats from human activities too. The increasing demand for different types of resources and pollutions of air, water and soil are some of the factors that have put wildlife in distress across the globe.  

The Global and Indian Scene

According to the IUCN- Red list-2000, about 1130 species of mammals and 1183 species of birds have been declared to be threatened on the global level. As per assessment made in 1996, there were about 169 species of mammals and 168 species of birds considered to be critically threatened in the world. These numbers increased considerably by the year 2000 and the number of critically threatened species of birds increased unto 182. The wildlife experts in the world are of the opinion that with the current trend of loss of species or the extinction, about 15 to 20 percent loss of species of wildlife is feared to occur over the next 100 years.

Extinction may be defined as a condition when no live individual of a particular species exists anywhere in the world, either in its natural habitat (in situ) or in captivity (ex- situ).Some species of wildlife are known to play more significant roles in a particular ecosystems than other species. Such species are called as key- stone species. The loss of such species becomes seriously destructive to ecosystems.


The Zoological Survey of India and the Botanical Survey of India have surveyed more than 70% of the total geographical area of India for the assessment of total number of species of plants and animals. So far, about 81,000 species of animals and 49,000 species of plants,have been recorded by these two institutions, respectively.
According to the IUCN- red list, released on 28th September 2000, the environmental status of species of plants and animals in India is detailed below.


Table. Status of species of plants and animals in India 



CAUSES OF LOSS OF SPECIES

The number of species of wildlife is declining through out the world at an unprecedented rate. Some of the important causes of this loss of species are mentioned below.


Habitat Destruction or Conversion of Land

Vast areas of forest lands are being converted into agricultural land, mining land, pasture land etc. Industrial, residential and municipal construction works grab vast areas of productive land at a fast rate due to explosion of human population. The varying pattern of land use like agricultural development, logging, construction of dams, and urban development lead to serious modifications of habitats. Water bodies like lakes and ponds, wetlands and even coastal lands are being reclaimed for different purposes. All these practices of habitat destruction are causing decline in the number of species of wildlife.

Virtually every type of habitat has come under stress over the past three decades. According to an estimate made by Food and Agricultural Organisation (FAO) , the forest covers in developing countries declined by 2 million sq. km in the world annually from 1980 to 1995. About 20 percent of the fresh water species have gone extinct or threatened.


Climate Change

The climate change has emerged as one of the major potential threats to the existence of wildlife especially to the small animals. The bleaching of coral reefs has been reported to occur due to rise in the global temperature. In Indian Ocean, bleaching of coral reefs caused mass mortality of corals (up to 90%) in an area of more than thousands of sq. kilometres. The decline of amphibian population in the Tropical Montane forests and mysterious extinction of the golden toads of Florida, have been reported to be caused due to the changes in the climate. Studies done on the depletion of the ozone layer reveal that excess ultra violet radiations reaching to the earth are killing embryos of Salamanders due to which these are being vanished from the earth.

Deposition of Nitrogen

The increasing use of fertilizers is causing the deposition of nitrogen in soil which is leading to the loss of soil organisms. Water bodies are subjected to nitrogen deposition due to joining of surface run offs from crop fields. This condition leads to eutrophication, increase in the toxic algal bloom and deaths of aquatic organisms.


The oil spills are causing loss of species of marine animals. A total of 108000 tonnes of oil were spilled into marine and inland environments as a result of 215 incidents in the world during the year 1998.

Hunting Poaching and International Trade

Hunting and poaching are dangerous practices causing mass scale loss of species of wild animals. Animals are being hunted for meat, sports and ill legal trade in their body parts since time immemorial. One of the most significant forms of hunting is whaling as a result of which stocks of whales have gone to the brink of extinction in many parts of the world. The international trade in animal body parts and products derived from them has reached up to the international value of US$ 10 000 million per year.
                      
Invasive Species

Foreign organisms that colonise native ecosystems are called as invasive species. The introduction of predatory snails named as Euglandina rosea caused serious loss of endemic land snail species named as Polynesia. Similarly, the introduction of Australian Brush Tail Possums caused serious decline in the New Zealand’s native birds.



Land snail

Pollutions

The pollutions of air, water and land are killing vast variety of birds, insects and aquatic organisms. The use of different types of deadly pesticides in agriculture is causing mass scale deaths of field sparrows, pea cocks and other birds. The population of the white-backed vultures is declining due to the presence of declophenacs in the dead bodies of cattle once treated with this anti- inflammatory drug. Fortunately, our scientists have become successful in synthesizing a new alternate drug named meloxicam.





Image:Vultures: Facing Extinction due to eating flesh of declophenacs contaminated dead bodies of animals.


NEED OF WILDLIFE CONSERVATION

We know that our environment cannot remain complete or balanced without the existence of wildlife. We need to conserve and manage our wildlife due to following reasons-

1. Living organisms regulate gaseous composition of atmosphere, hydrological cycles, and climate and soil fertility.

2. Marine organisms are important for the protection of coastal zones.

3. Micro- organisms and certain other animals are important for the disposal and breakdown of wastes.

4. A large number of insects, birds and other animals are associated with the pollination of crops and other flowers.

5. Plants play important roles in the absorption pf pollutants.

6. Wild organisms serve as important sources of medicines for human health. As per reports of UNEP-2000, out of 25 top selling drugs in 1997, 10 were derived from wild sources alone. The global market value of medicines derived from wild sources has been estimated to be US$ 75000 to 150 000 million annually. About 75 percent of the world population rely for health care on traditional medicines that are directly derived from plants and animals growing in the wild.

7. Wild life are regarded as social, cultural, and national assets in India .Hence, we have National Bird and National Animal as well as State Bird and State Animal on government levels.

8. Wildlife constitutes the biological basis for world food security and support for human livelihood. So many types of wild plants are of great importance to global and national economies. They are our important genetic resources also.

Key Words : wildlife, keystone species, species loss, IUCN, red-data list, golden toad, landsnail, UNEP, FAO, National Animal, State bird

No comments :

Post a Comment

Note: Only a member of this blog may post a comment.