EXTINCT & ENDANGERED

SPECIES

What is Biodiversity?

Biodiversity is the degree of variation of life. It is a measure ofthe variety of organisms present in different ecosystems. Thiscan refer to genetic variation, ecosystem variation,or species variation (number of species) within an area, biome,or planet. Terrestrial biodiversity tends to be highest nearthe equator, which seems to be the result of thewarm climate and high primary productivity. Biodiversity is notdistributed evenly on Earth. It is the richest in the tropics.Marine biodiversity tends to be highest along coasts in theWestern Pacific, where sea surface temperature is highest andin the mid-latitudinal band in all oceans. There are latitudinalgradients in species diversity. Biodiversity generally tends tocluster in hotspots, and has been increasing through time butwill be likely to slow in the future.

But Why Is It Important To Talk About

Biodiversity

Biodiversity is important since it provides us with raw materials that we useto make products such as clothes, shoes and paper. We humans live in anenvironment filled with biodiversity. Our each and every activity affects us aswell as our environment. Some may be useful and other may be adverse.

Although we use many natural products andmaterials in our daily lives, we also use manyhuman-made chemical cleaners, fertilizers, bugspray, pesticides, and many others. Even though weuse them to help us, they have many sideeffects. Toxins and pollutants are very harmful tobiodiversity. The chemicals that we use end up in ourwaterways. Plants and animals are killed by oilspills. Wildlife gets caught in plastic trash.

What affects Biodiversity?

Humans affect their surroundings through their activities in manyways.

Some major human activities about which we will discussin detail, are:-

Deforestation

Pollution [Air, Water & Soil]

Dam Construction

Industries

Mining [and]

Uncontrolled Resource Extraction

Human Activities

Deforestation is the permanent destruction of forests inorder to make the land available for other uses. An estimated 18million acres (7.3 million hectares) of forest — roughly the size ofPanama — are lost each year, according to the United Nations'Food and Agriculture Organization (FAO).

Deforestation is considered to be one of the contributingfactors to global climate change. Trees absorb greenhouse gasesand carbon emissions. They produce oxygen and perpetuate thewater cycle by releasing water vapor into the atmosphere.Without trees, forest lands can quickly become barren land.

Deforestation

Pollution is the introduction of contaminants into thenatural environment that cause adverse change. Pollution can take theform of chemical substances or energy, such as noise, heat orlight. Pollutants, the components of pollution, can be either foreignsubstances/energies or naturally occurring contaminants.

Air pollution:- The release of chemicals andparticulates into the atmosphere. Common gaseous pollutantsinclude Carbon monoxide, Sulphur dioxide, Chlorofluorocarbons (CFCs)and Nitrogen oxides produced by industry and motor vehicles.Photochemical Ozone and Smog are created as Nitrogen oxidesand Hydrocarbons react to sunlight. Particulate matter, or fine dust ischaracterized by their micrometre size PM10 to PM2.5.

Pollution

Water pollution, by the discharge of waste water from commercial

and industrial waste (intentionally or through spills) into surfacewaters; discharges of untreated domestic sewage, and chemicalcontaminants, such as chlorine, from treated sewage; release ofwaste and contaminants into surface runoff flowing to surface waters(including urban runoff and agricultural runoff, which may containchemical fertilizers and pesticides); waste disposal and leachinginto groundwater; eutrophication and littering.

Soil contamination or pollution occurs when chemicals arereleased by spill or underground leakage. Among the most significantsoil contaminants are Hydrocarbons, heavy metals, MTBE, herbicides,pesticides and chlorinated Hydrocarbons.

When a dam is constructed, be it for hydropoweror water supply, the destruction is highly visible.But the environmental impacts of a dam stretchmuch further downstream than the location ofthe actual dam site.

Dams block migratory fish species from their spawning and feeding sites.

Dams disturb natural fluctuations in water flow. This can be

particularly damaging in seasonal floodplains, affecting deposits of nutrients as well as the lifecycles of species that depend on these fluctions for feeding and breeding grounds. Dams change daily flows by releasing water as a reaction to human demands, like energy and irrigation, instead of as nature intended.

Water quality can be degraded Reductions in water quantities can

increase salinity and make the water unusable for drinking and irrigation. Decomposition of organic matter and the leaching of mercury from the soil can introduce toxins.

Dam Construction

The transport of sediment along the river is disrupted. This affects the morphology* of the riverbed, downstream floodplains, and even coastal deltas. In turn, this can increase flood risk

Reservoirs can emit climate-changing greenhouse gases.Particularly in tropical areas, the release of carbon dioxide (CO2) and methane as flooded trees and plants decompose is a serious cause for concern that needs more investigation.

Dams destroy the nearby vegetation completely. Dams require very large piece of land for their construction. Therefore large area is cleared.

Morphology*- Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, colour, pattern) as well as the form and structure of the internal parts like bones and organs.

(In this text morphology deals with river)

1. It leads to the depletion of natural resources.

2. It leads to air pollution, water pollution and soil pollution.

3. Global warming, climatic changes are the major consequences of industrialization.

4. It causes acid rain.

5. It leads to the degradation of land quality.

6. It leads to the generation of hazardous waste whose safe disposal become a big problem.

7. These industries are responsible for the adverse diseases and ill effect like silicosis and pneumoconiosis, tuberculosis, skin diseases and deafness.

Industries

1. Metallic contaminant like Cd, Zn, Hg, etc., destroy bacteria and beneficial microorganisms in the soil.

2. Industrial wastes including toxins enter in the food chain causes number of undesirable effects to living beings and animals.

3. Industrial effluent damages the natural biological purification mechanism of sewage treatment causing several soil and water borne diseases.

4. Radioactive industrial pollutant cause undesirable disease when food containing radio-nuclides is taken by man.

ILL Effects of Industries:

Adverse effect of mining includes erosion, formation of sinkholes, loss

of biodiversity, and contamination of soil, groundwater, surfacewater by chemicals from mining processes. In some cases,additional forest logging is done in the vicinity of mines toincrease the available room for the storage of the created debris andsoil. Besides creating environmental damage, the contaminationresulting from leakage of chemicals also affect the health of thelocal population. Mining companies in some countries are requiredto follow environmental and rehabilitation codes, ensuring the areamined is returned to close to its original state. Some miningmethods may have significant environmental and public healtheffects.

Mining

The exploitation of natural resources started to emerge in the19th century as natural resource extraction developed. During the20th century, energy consumption rapidly increased. Today, about80% of the world’s energy consumption is sustained by the extractionof fossil fuels, which consists of oil, coal and gas. Another non-renewable resource that is exploited by humans are Subsoilminerals such as precious metals that are mainly used in theproduction of industrial commodities. Intensive agriculture is anexample of a mode of production that hinders many aspects ofthe natural environment, for example the degradation of forests ina terrestrial ecosystem and water pollution in an aquatic ecosystem.As the world population rises and economic growth occurs, thedepletion of natural resources influenced by the unsustainableextraction of raw materials becomes an increasing concern.

Uncontrolled Resource Extraction

• As a result of all this, many species arebecoming extinct. Oxygen level is decreasingday by day.

• It is now very dangerous to collect waterfrom many rivers because of water pollution.

• Consumption of food grown incontaminated soil is a great threat to livingbeing.

• There are many more affects.

Affects of these activities

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Content Sources:-

A Science Presentation By-

Kushagra Garg

Ixth ‘E’Delhi Public School,

Gwalior