HIPPO

The world is losing species and biodiversity at an unprecedented rate and its cause go deep ranging from a complex combination of social, economic, political and biological factors. There is a biodiversity crisis that has done irreparable harm to the countless species and the assaults come from so many directions that nature can’t adjust. 

 E.O Wilson a revolutionary biologist has coined the acronym HIPPO to describe these multiple assaults: habitat destruction, invasive species, pollution, population increase and over-grazing. 

HABITAT DESTRUCTION

The word ‘Habitat’ means living space. This refers to the process which habitat is unable to support the species present, resulting in the species being displaced or destroyed and a reduced biodiversity. Clearing habitats for agriculture is the primary reason of habitat destruction. Mining, logging, trawling and urban sprawl as also some other reason. . About 89% of bird species, 83% of mammals and 91% of plant species have become extinct due to habitat destruction. As the climate changes, the current habitats of innumerable plant and animal species will no longer be suitable for them, because of changes in temperature, precipitation, storm frequency etc.  

-          Impact of Habitat Destruction: When a habitat is destroyed the plants, animals and any other species occupied in that habitat are threatened since the habitat no longer has the capacity to sustain the species.

INVASIVE SPECIES

This refers to when non-indigenous species compete with the current species in a habitat for resources.

Invasive species refers to species, plants and animals which are non-indigenous or non-native and have an adverse affect on the habitat they invade. They disrupt by dominating the region. This term has been uses by International Union for Conversation of Nature (IUCN).

Invasive species could also include when native species disrupts the habitat by becoming dominant due to loss of natural controls. (For example overpopulation a particular species). Common traits of an invasive species are: the ability to reproduce both asexually and sexually, fast growth, rapid reproduction, high dispersal rate, ability to adapt to suit the conditions. These are also reason for its dominations in habitat areas. Lantana in India is a common invasive species.

Examples – Nile Perch are large fish found in River Nile which were introduced in Lake Victoria in Africa and thus were responsible for the destruction of one entire habitat. Water hyacinth, water species from Mexico, have choked water bodies in India and replaced natural vegetation. Eucalyptus and Wattle have destroyed native forests in the mountains of the Western Ghats in Tamil Nadu.

POLLUTION

Pollution comes in three forms: solid, liquid and gaseous waste. Hence there are three types of pollution: air, water and soil pollution. Pollution occurs when there is presence of substances beyond their permissible limits in the atmosphere or water. It is the most subtle form of habitat destruction, leading to loss of biodiversity and contamination or disturbance of existing equilibrium. Pollution can also cause reduction and elimination of sensitive species. Water pollution is caused by dumping organic and human wastes, agricultural wastes and industrial effluents into the river and ocean systems. Pesticides get mixed with the water and poison the fish. Coral reefs are in danger by pollution and industrialization. Inorganic wastes lead to Eutrophication or dying of water bodies. Air Pollution is one of the major causes of Global Warming.  Sulphur Dioxide, Nitrogen Dioxide and suspended particles have an adverse effect on plant and animal species. Pollution through biomagnifications can affect all forms of life.

POPULATION

The population of the world is 6.2 billion and is expected to rise to 9 billion by 2050. This raises the question whether there will be enough resources to sustain the population. The large global population of today, has put immense pressure on the habitat to sustain itself. Natural resources are exploited at a destructive rate. There are water shortages, soil exhaustion, loss of forest, air and water pollution.  Most developed economies are consuming faster than they can regenerate.

Protecting the environment and achieving better standard of living go hand in hand. Slowing the increase of population will reduce pressure on the environment, and gain time to improve standard of living on a sustainable basis. Human Settlements and our expanding needs have turned into encroachment on habitats of species. Most developed economies are consuming faster than they can regenerate. There is a need for population stabilization and resources conversation for the world to meet the challenges of sustainable development. 

  

OVER-HARVESTING

It is essentially about sustainable use of renewable resources whether it is forests or fisheries. Overharvesting pushes the ecosystem beyond repair. A large number of forest lands are continuously cleared to convert it to grazing land for cattle. India has a grazing land of only 13 million hectares and so more land is cleared. The animals trample the seedlings and lead to a decrease in the water storing capacity of the soil. Overgrazing destroys grasslands; plants become weak and have reduced root strength. It leads to the inability of the forests to perform their functions like acting as the catchment for rivers etc.

@Notes courtesy of Aparna, Shruti Gokhale, Dhanika and myself