Human Impact on Biodiversity

Human impact on Loss of Biodiversity

Biodiversity is also made up of insects, fungi, bacteria, and other living beings. These have traditionally been hard to study and quantify due to their small size or "hard-to-access" living environments. Animals only represent a tiny portion of all biomass on Earth, and we believe that anthropogenic loss of biodiversity has been even more significant on plants and arthropods (insects - phylum Arthropoda).

Below, we will look at a few ways human are impacting biodiversity.

Direct exploitation

This is a type of exploitation in which humans normally come in direct physical contact with the biodiversity resources. This includes:

• Food: the nutritional or cultural values attributed to certain foods override the need for care needed due to the resource's scarcity. This includes the Bluefin Tuna Thunnus Thynnus and the Chinook Salmon Oncorhynchus tshawytscha. This means that they keep being caught and used in traditional cuisines around the world, despite becoming rarer.
• Fashion: in the USA, great egrets and roseate spoonbills had been overhunted in the 19th century for their bright feathers.
• Exotic pet trade: the African grey parrot Psittacus erithacus is endangered by the pet trade.
• Unsustainable traditional medicines: all parts of the tiger, including bones, internal organs, and whiskers, are believed to hold specific medicinal properties in Chinese medicine. The South China tiger is on the verge of extinction in the wild.
• Eradication of competition: the intentional elimination of a species for various reasons. 30 million American bison were culled in the 1800s due to the intraspecific competition for space and resources between human settlers and North American indigenous tribes. Pelicans may also be seen as pests by fishermen, although the pelicans' role in the ecosystem is extremely valuable.

Indirect Exploitation

Indirect exploitation is often unintentional, as it results from primary human activities that may not specifically target the elimination of biodiversity. This includes:

• Accidental introduction of alien species with negative consequences: earthworm Lumbricus terrestris introduced in North America; ash dieback fungus Hymenoscyphus fraxineus imported into the UK through the sapling trade.
• Bycatch: bycatch from industrial fishing alone can lead to species extinctions of sharks and dolphins, due to the rate at which they get caught in nets and asphyxiate.
• Changes in abiotic factors: heat island effect, soil compaction due to heavy weights, reduced humidity.
• Food chain impacts: primary extinctions can cause a number of other extinctions down the line, in a form known as the domino effect. The disappearance of the dodo bird from the island of Mauritius is leading to the extinction of the Calvaria major tree.
• Habitat loss: fragmentation brings the loss of genetic resources and leads to inbreeding (inbreeding depression) within existing populations limited by geographical conditions. Cheetahs are affected by this.

Human Impact on Biodiversity Examples

Each species and habitat has a unique role to play in the functioning of the ecosystem. The loss of even one species can have a ripple effect on an entire community and their habitat.

The Aral Sea - net biodiversity loss

68,000 square km of landlocked sea had completely dried up in 2014 for the first time in recorded human history, primarily due to a series of water extraction projects for irrigation of plants such as cotton, which unintentionally caused the ecosystem to collapse. Twenty-four species of endemic fish species went extinct in 60 years, and roughly 80% of native Aral Sea invertebrates might have died out.

The Great Pacific Garbage Patch

This is a 1.6 million square kilometres collection of floating marine debris which resulted from human activities - a collection roughly four times the size of Britain. This debris, mostly made of plastics, accumulates in the digestive systems and tissues of animals that feed at sea (e.g. jellyfish) causing health complications and even death.

The Molai Forest - net biodiversity gained

The origins of the Molai Forest Reserve are attributed to one person's efforts. A forestry worker named Jadav Payeng, born from the Mishing indigenous tribe, had planted and taken care of a forest in Assam, India, over several decades. This forest area now measures 550 acres and comprises various tree species native to the Indian subcontinent, such as the arjun Terminalia arjuna. Animal species such as Asian elephants, Bengal tigers and Indian rhinoceroses use the forest for foraging, shelter and reproduction.

Positive Human Impacts on Biodiversity

Human conservation efforts can help reverse biodiversity damage or loss caused by natural events and disasters, thus rendering an ecosystem more resilient. In most cases, regulations are in place to prevent over-exploitation by humans or to alleviate habitat damage.

Biodiversity Loss and its Impact on Humanity (Summary)

It is now widely recognized that biodiversity loss is one of humanity's most serious environmental problems. Biodiversity loss can be defined as a decrease in the number or variety of species in an ecosystem. This can happen through habitat loss or degradation, overexploitation of resources, pollution, invasive species or climate change. All of these threats are caused by human activity.

Effects of biodiversity loss include:

• Loss of livelihoods and income

• Health impacts

• Local migration

• Conflicts

• Loss of food resources

• Higher temperature variations, flood incidence, wind

For example, the loss of pollinators such as bees and butterflies has led to a decline in crop yields, with knock-on effects on food supplies.

Rainforests also provide ecosystem services such as:

• Regulating atmospheric moisture levels and precipitation patterns

• Other water cycle regulation

• Flood prevention

• Carbon storage

• Timber

• Food

• Medicine (discovered, and potential)

• And other natural resources that are vital to human society.

Hopefully you now have a better understanding of the impact that we have on biodiversity and also the ways that you can help mitigate them.