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Effect Of Man Made Hazard On Wildlife And Aquatic Life

Effect Of Man Made Hazard On Wildlife And Aquatic Life

By Madhumanti Gupta & Nilanjana Deb (UG 3rd year, Department of Life Sciences, Presidency University)


Man-Made Hazards are events that are caused by humans and occur in or close to human settlements for the sake of development, tourism, transportation, etc. The events leading up to a man-made hazard may be the result of deliberate or negligent human actions, but their impact is devastating. Events such as gas leaks, oil spills, nuclear meltdowns, industrial fires, disposal of industrial wastes and plastics in water body and deforestation have grave consequences.


The forest covers 31% of Earth’s land. The plants and animals are integral part of the forest ecosystem and provides human with several benefits. But deforestation has led to the disturbance to the ecosystem. Deforestation is uncontrolled cutting down of trees and clearing of patches of forest to overcome the increasing demand of timber, food, space, commercial logging.

Consequences On Environment

The worst consequence of deforestation is increase in the rate of pollution, increase in CO2, leading to increase in global warming and weather change.

Consequences On Wildlife

Deforestation leads to direct loss of wildlife habitat. Removal of trees and vegetation reduce their available food source, shelter and breeding habit. It affects the birds, aerial animals, the tree dwelling animals and those living in the burrows of trees.Thus,leading to gradual disappearance and extinction of the vulnerable species.

Loss of trees – loss of food – increasing competition (intraspecific) – increasing competition (interspecific) – starvation- gradual decrease in number – biodiversity loss.

Interaction Between Human And Wildlife

Modernisation of human being leads to extension of rails and roads through the forest lands, thus blocking and destroying the corridor of the native habitants of the forest(wildlife). There are often reports on wildlife hit by vehicles when they try to migrate to a new space or roam about the forest. Since they have no idea about man and their discoveries. Herd of elephants hit by train, deer hit by vehicles. The man-made wildfire to clear out large patches of land at once causes death of several wildlife. Moreover to fulfil the greed, there is an increasing vulnerability to predation, poaching, slaughtering for hide, tusks, horns etc.

Oil Spills

Oil spills occurs due to leakage in oil tanker into the ocean while exporting or importing. Oil spills affects marine birds and mammals as well as fish and shellfish drastically.Oil destroys the insulating ability of fur-bearing mammals, such as sea otters, and the water repellence of a bird’s feathers, thus exposing these creatures to the harsh elements. Many birds and animals may ingest oil when they try to clean themselves, which can poison them. When adult fishes exposed to oil they experience reduced growth, enlarged livers, and changes in heart and respiration rates, fin erosion, and reproduction impairment. Oil also adversely affects eggs and larval survival thus challenging the population of fish.

Effect Of Plastics And Industrial Waste

Plastic is non biodegradable as it can neither be degraded by microorganisms nor by enzyme present in stomach of animals. Fish, seabirds, sea turtles, and marine mammals can become entangled in or ingest plastic debris, causing suffocation, starvation, choking and drowning. When these plastic objects are ingested,it take up space in stomach thus causing starvation. Sometimes plastic straw blocks nasal pathway. It also gets choked during ingestion, which can be hazardous.

Discharge of industrial waste into water bodies alters the pH due to which phytoplankton’s, fishes etc. die thereby disturbing the aquatic food chain and the ecosystem. There are many toxic chemicals which lead to mortality of aquatic animals and the animals which are drinking the water and feeding upon aquatic animals.


Radiations, air pollution, noise pollution, global warming, heavy metal poisoning are also threatening wildlife to great extent. Radiation from nuclear waste and leak in nuclear reactors causes DNA damage and altering of DNA sequences. Noise pollution terrifies animals and makes them homeless. Global warming affects the climate due to which migration of birds alters and sometimes proves to be life threatening to them. So, before it’s too late measures should be taken to prevent wildlife exploitation from man-made hazards.

Points To Ponder

  • When seals and otters try to clean oil matted on their coats, they ingest it. They also lose heat because spilled oil ruins their natural insulation, so they can die of hypothermia.
  • Marine plastic pollution has effected over 267 species worldwide as a result of ingestion, starvation, suffocation, infection, drowning, and entanglement.
  • It is estimated that about 3-7 billion tress are cut annually. Some of the most affected regions of the world are The Amazon Rainforest, Sumatran jungles, British Columbia.
  • Many wildlife has been marked as critically endangered like the Black Rhino, Amur Leopard, Orang-utans are endangered like the tigers, vulnerable by the record of the Red Data Book. The rate at which the human activity is interfering with the wildlife and ecosystem, they are soon going to be get extinct in the near future.
  • Oil spills affect mangroves adversely by blocking the pneumatophores which help them in respiration and results into their death which serves in deforestation and also loosening of soil.

Trees serve home for birds

Human interference with wildlife

Modernization – threat to wildlife

True residents of forests

Conservation of forests and wildlife