Question

List out the various causes for biodiversity losses.

List four causes of biodiversity loss.

Answer 1

There are four major causes of biodiversity declines and losses.

• Habitat loss, fragmentation and destruction (affects about 73% of all species).
• Pollution and pollutants (smog, pesticides, herbicides, oil slicks, and GHGs).
• Climate change.
• Introduction of alien/exotic species.
• Overexploitation of resources (poaching, indiscriminate cutting of trees, overfishing, hunting, and mining).
• Intensive agriculture and aquacultural practices.
• Hybridization between native and non-native species and loss of native species.
• Natural disasters (Tsunami, forest fires, earthquakes, and volcanoes).
• Industrialization, Urbanization, infrastructure development, Transport - Road and Shipping activity, communication towers, dam construction, unregulated tourism, and monoculture are a common area of specific threats.
• Co-extinction.

Answer 2

There are four major causes popularly known as ‘The Evil Quartet’.

1. Habitat loss, alteration, and fragmentation: Human beings encroach and exploit the natural habitat of plants and animals for various reasons, such as the cultivation of crops having commercial value, extracting resources, and so on. The transformation of natural areas results not only in the loss of plant species but also in a decrease in the animal species associated with them. When large habitats are fragmented by various human activities, mammals and birds that require large territories, as well as certain migratory animals, are severely affected, leading to population declines.
2. Over-exploitation: Human beings are dependent on nature for their basic needs, such as food, clothing, and shelter. But with technological advancements, human beings have explored many other uses of nature. Therefore, their need has turned into greed. Activities such as hunting, fishing, and others have led to the extinction of various species, a result of our overexploitation of natural resources. The extinction or nonparticipation of a single species significantly affects the ecological balance.
3. Alien species invasion: When a new species gets introduced into any ecosystem accidentally or intentionally, there are chances that it proves harmful for existing species. Sometimes, it can lead to the extinction of local species. In such a case, it is called an invasive species.
4. Co-extinctions: Many a time, organisms are associated with each other in an obligatory way. In such cases, extinction of one variety leads to loss of associated variety from the ecosystem.