Influence of Humans

Key Concepts

• Biodiversity
• Overexploitation
• Habitat loss and Fragmentation
• Biomagnification
• Poaching
• Overpopulation

Introduction: 

Biodiversity: A variety of plants or animals living on land, water, and in the atmosphere and their interdependency in a particular habitat. 

Biodiversity is important ecologically, and economically and it sustains life on earth. 

Biodiversity is changing drastically; we have seen animals going extinct. 

Deforestation has also resulted in habitat loss, with no trees and no shelter, causing animals to migrate or become endangered. 

So, certain human activities are leading to biodiversity loss. 

Explanation: 

Let us understand human activities leading to biodiversity loss. 

Apart from the causes shown in the figure, overpopulation of humans, poaching of animals, and pollution are the other causes of the loss of biodiversity.  

Overpopulation

Overpopulation occurs when the human population surpasses the carrying capacity of the natural environment. In an overcrowded environment, people may outnumber available necessary commodities for survival, such as transportation, water, shelter, food, and social facilities. 

With the growing population, urbanization increases resulting in habitat loss, loss of natural resources, increased agriculture, and over-exploitation; all of these lead to pollution and a rise in diseases, affecting the environment adversely.  

Poaching of Wildlife

Poaching of wildlife is the killing of wild animals for their meat, recreation, or products obtained from them. 

Like the skin of a tiger, a deer; fur of a yak, a grizzly bear, the horns of a rhino, and the tusks of the elephant. 

Poaching leads to an imbalance in the ecosystem leading to the extinction of animals or loss of biodiversity. 

Poaching damages biodiversity as well as entire ecosystems by removing endangered animals from their natural habitats.  

Wild animals, which grow more valuable as they get scarcer, are targeted by poachers.  

The extinction of one species can set off a cascade of events that result in the extinction of other plants and animals, or perhaps the collapse of the entire ecosystem. 

Habitat Loss

Habitat loss is the process by which a natural habitat loses its ability to support native species.  

The organisms that used to live on the site have been moved or killed, lowering biodiversity and species abundance. 

Many animals lose their habitat or become endangered or extinct due to excessive land use by humans for urbanization, deforestation, and land use for agriculture, mining, etc.  

Fragmentation is also a result of human activity where patches of habitat are cut into smaller pieces. 

Habitat fragmentation has a significant impact on biodiversity because it reduces the amount of suitable habitat available to organisms.  

Habitat fragmentation frequently involves the destruction of habitat as well as the segmentation of previously continuous habitat. 

Over Exploitation 

Overexploitation, which happens when harvesting of wild plant and animal species exceeds reproduction, continues to be a major threat to biodiversity.  

Overexploitation of a resource can lead to its extinction. 

Over harvest of medicinal plants for their use or overfishing may lead to ecological imbalance in the ecosystem leading to the loss of biodiversity. 

Introduction of Invasive Species 

An organism introduced into a new habitat where it does not belong is called an invasion. 

It is a threat to biodiversity, as these species multiply very soon, dominating other species. 

Generally, humans transfer these organisms or an invasion may occur accidentally. 

For example, This cane toad was introduced in Australia by humans to control insects in agriculture. These multiplied extensively and killed many organisms by releasing their poison. 

                                                         

Pollution

Pollution is an unwanted change in the physical, chemical, or biological features of air, water, or soil that can disrupt the life of any living organism or pose a health risk. 

 A pollutant is any material that produces pollution. There is a huge accumulation of gaseous, liquid, and solid pollution in the environment as a result of the lack of development of a pollution control culture. 

 It is necessary to clean it. Controlling pollution is a new environmental concern.  

Pollution is a man-made problem that primarily affects developing countries. 

Pollution is divided into three types: 

1. Air Pollution
2. Land pollution 
3. Water pollution   

Air pollution: 

Air pollutants from various sources like automobiles, industries etc., pollute the atmosphere leading to genetic variations, genetic diseases, and respiratory diseases in organisms. Air pollutants settle on plants and enter the food chain. 

Land Pollution:  

Overuse of chemical fertilizers and pesticides pollutes the soil making it unsuitable for agriculture. Also releasing non-biodegradable materials like plastic pollutes the soil and makes it unfavorable for plant growth. 

Likewise, these pollutants enter the food chain via producers and affect other organisms leading to the loss of biodiversity. 

Water pollution: 

Oil spills are one of the causes of water pollution as discussed. 

An oil spill is a pollution event that occurs when a liquid petroleum hydrocarbon is released into the environment, particularly the marine ecosystem, as a result of human activities.  

Whales, dolphins, seals, and sea otters are commonly killed by oil spills.  

10 Oil can clog whale and dolphin blowholes, preventing them from breathing properly and interfering with their communication abilities. 

Oil coats otters’ and seals’ fur, making them susceptible to hypothermia. 

Another major effect is biomagnification. 

The process in which pollutants released in the water enter the food chain in higher concentration. 

Mostly the heavy metals like arsenic, mercury, and DDT present in pesticide sprays find their way into lakes, rivers, and the ocean, where they are incorporated into the diet of aquatic organisms like zooplankton, which are then eaten by fish, which are then eaten by larger fish, large birds, animals, or humans. 

                                    

  

Some of the measures to prevent human activities are: 

• Reduce population through family planning, and birth control methods. 
• Reduce, reuse and recycle materials to limit waste. 
• Prevent illegal poaching methods. 
• Use of biofertilizers and biopesticides. 
• Stop the invasion of foreign species. 
• Avoid deforestation for housing or urbanization, and encourage afforestation. 
• Use of microorganisms to remove the oil spills instead of chemicals. 
• Creating natural sanctuaries for endangered species. 
• Reduce the use of fossil fuels and combustion, instead use biogas for cooking and solar energy in small-scale industries. 

Summary

• Biodiversity: A variety of plants or animals living on land, water and in atmosphere and their ecosystems in a particular habitat. Biodiversity is important ecologically, economically and it sustains life on earth.
• Humans contribute to the loss of biodiversity in the following ways.
• Over population: With growing population urbanization increases resulting in habitat loss, loss of natural resources, increased agriculture, over exploitation, leads to pollution and rise in diseases, affecting the environment adversely.
• Poaching of Wildlife: Poaching of wildlife is killing of wild animals for their meat, recreation or products obtained from them.
• Habitat Loss: Many animals lose their habitat or become endangered or extinct due to excessive land use by humans for urbanization, deforestation, land use for agriculture, mining etc.
• Fragmentation is also an effect, where patches of habitat are cut into smaller pieces.
• Over exploitation: Over harvesting of medicinal plants for their use or overfishing may lead to ecological imbalance in the ecosystem leading to the loss of biodiversity.
• Introduction of invasive species: An organism introduced into the new habitat where it does not belong is called invasion.
• Air pollutants from various sources like automobiles, industries etc., pollute the atmosphere leading to genetic variations, genetic diseases, and respiratory diseases in organisms.
• Overuse of chemical fertilizers and pesticides pollutes the soil making it unsuitable for agriculture.
• Reduce population through family planning and birth control methods are two examples of efforts to prevent human activities.
• To reduce waste, reduce, reuse, and recycle materials. Prevent the use of unlawful poaching techniques. Biofertilizers and biopesticides should be used.
• Stop the invasion of non-native species. Encourage afforestation instead of deforestation for housing or urbanization.
• Instead of using chemicals, microorganisms are used to clean up oil spills. Natural sanctuaries for endangered species are being established.
• Reduce the use of fossil fuels and combustion in small-scale companies and replace them with biogas for cooking and solar energy.