Humans Are to Blame for Increased Rate of Extinction

          

Photo by Nels Israelson

The earth is currently facing its most catastrophic crisis since the extinction of the dinosaurs; this time it is not due to natural events or due to evolution’s natural selection, but rather due to human activities like urbanization and pollution. The human population is to blame for causing what very well may be the Earth’s sixth mass extinction and unfortunately the mass catastrophe is occurring at an alarming rate. In the past, a multitude of species had time to evolve and adapt to their surroundings. Now, the rate of extinction in certain species is happening ten-thousand times quicker than before due to human interference, preventing species time to adapt to their ever-changing environments; it is predicted that thirty to fifty percent of all species will be endangered at risk of going extinct in fifty years (“Protect and Serve”). This can be witnessed within the last two thousand years when, for example, humans had colonized Madagascar who then caused the extinction of species like elephant birds, hippos, and large lemurs (“Human Population Growth”). Recent research has shown that the rate of extinction of both particular plant and animal species has increased; furthermore, they will continue doing so at a catastrophic rate unless human activities like urbanization, farming, and pollution are lessened to improve conservational regulations and restrictions that decrease their negative effect on the environment, protect endangered habitats and species, and diminish their domination over ecosystems at risk by doing away with processes that destroy natural areas.

The human population is growing to become the largest group of vertebrate animal inhabitants the planet has ever seen, thus causing destructive effects on other animal and plant populations. With such a large population, humans have transformed nearly half of Earth’s surface area for their own use; forty percent of the planet’s land and half of Earth’s fresh water is used for human food cultivation (“Human Population Growth”). Rainforests and other natural lands are being destroyed and replaced with human development in attempt to meet the needs of the multiplying population, thus causing the populations of animals and plants in these severed areas to decrease due to loss of habitat that these species reside in (“Contemporary Mass Extinction”).

Photo by Peter

To name a few, pollution, overharvesting, environmental shifts, and the introduction of invasive species are just some examples of the fatalistic effects of human development. It is these activities that have driven the rate of extinction up to its current alarming rate. Pollution in the form of pesticides, herbicides, fungicides, and insecticides are consumed by unknowing animal species, causing them to become ill; furthermore, the run-off of the chemical pollutants contaminate local water systems at a detrimental degree. Coral reefs, sea grasses, and kelps in the Caribbean been greatly reduced by pollutants in the form of runoff having a negative effect on local populations of sea life causing large number of species to become ill in the surrounding areas where the toxins are present (“The Current Biodiversity Extinction Event”). Overharvesting is a human induced activity that destroys habitats in order to harvest food leading to the transformation of habitats. This is evident in the Lake Victoria area, located in East Africa, where the overharvesting of certain fish species in the lake has caused terrible impacts on the lake’s biodiversity (“The Current Biodiversity Extinction Event”). Twenty-four to thirty-five percent of diatom, an algae with a transparent cell wall made of silicon dioxide and is hydrated with a small amount of water, has been harvested via fish harvests, drastically reducing its population.

Environmental shifts, such as climate change, are altering the natural world and this rate of change will escalate and accelerate. Global warming is a major concern for those discussing environmental shifts because the warming of Earth is causing the glaciers to melt which species rely on to survive and even cause the sea levels to rise worldwide, which will eventually harm thousands of coastal species as the high water levels give rise to flooding. Caused by global warming, the heating of oceans is also altering the flow of both warm and cool water currents, impacting the nutrient-rich upwelling from the floor in the Southern Ocean off of the coast of Antarctica which aquatic species depend on as a food source. The amount of nitrogen has doubled due to human activity, thus causing excess nitrogen to sink into soils and the water sources, causing a negative effect on biodiversity in ecosystems (“The Current Biodiversity Extinction Event”). The introduction of invasive species, either brought about intentionally or unintentionally, through human activities has triggered native species of plants and animals to become extinct due to their inability to compete for natural resources with the invasive species; for example, when the Nile Perch was introduced into Lake Victoria, it resulted in the annihilation of two-hundred endemic cichlids (“The Current Biodiversity Extinction Event”).

These human activities have catastrophic impacts on the biodiversity of habitats all over the world; however, there are ways to decrease their influence on the rate of extinction or even rid their negative affects altogether. One way to decrease the effects of pollutants in various environments is to decrease their overall use and lower the intensity of the toxins so much so that the species within habitats where pollutants that were present beforehand would then be able to overcome the negative effects and once again flourish. This will require experimental work to determine how and to what extent to decrease the amount of toxins present in pollutants which would hopefully decrease future cases that report on pollutants that cause mass destruction towards species within infected habitats. In the case of overharvesting, there have been success stories in constraining overfishing; regulations on fishing have caused species like summer flounder, mackerel, and striped bass to stabilize populations that were once endangered or on the verge of disappearing altogether. Furthermore, lobsters off the coast of Maine have increased in numbers due to regulations placed on lobster harvesting (“The Current Biodiversity Extinction Event”). Although there has been a few successes, further positive results will depend on more advanced multispecies models and better harvesting strategies. In the case of environmental shifts and climate changes, the first step to decreasing its negative impact on extinction rates is by simply recognizing that it is, in fact, a problematic situation that must be dealt with in a timely manner.

Photo by  Mingjia Zhou

Nitrogen is the main contributor to environmental shifts, so by regulating the production of the additional nitrogen, it will constrain and monitor its use for a better environment. The use of fertilizers is one of the most impactful human causes of emission of nitrogen into the atmosphere. Studies have been conducted in Mexico where scientists attempted to reduce the use of nitrogen fertilizers; both the crop yield and the economic situation were sustained and, in some cases, had even improved. This proves that economies and food production are sufficient even without the use of nitrogen producing fertilizers, thus giving all the more reason to cease the unnecessary production of additional nitrogen that causes harm to species of plants and animals. The main component to decrease the effect that invasive species have on the rate of extinction is through the regulation of the maintenance on ecosystems in which invasive species are present. In conclusion, regulating human travel in a manner will help put an end to the unintentional origination of invasive species and the fragmentation of habitats so that it restricts the gene flow exchange of the resident, noninvasive organisms.


Regulations and an increased conservation effort in these particular fields should decrease the negative human influence on the environment and rejuvenate the biodiversity that has been lost. There is hope, The United Nations Environment Programme (UNEP) has announced that an additional 6.1 square kilometers of areas of ocean and land have been set aside for the protection of habitats, making the total area of land set aside for protection on Earth roughly about the size of Africa (“Protect and Serve”). But this is not enough. If the rate of extinction of animal and plant species is to truly drop, then the human population as whole most make regulations and diminish harmful activities on the environment that they are directly responsible for. It is crazy to think that a single species can be accountable for the annihilation of thousands of others, but the human species and their impacts on their surrounding environment are proving this thought to be not so absurd. If nothing is done to correct the negative effects of human proceedings, then Earth could very well experience is next mass extinction.

Works Cited

"Protect and Serve" http://www.nature.com.prox.lib.ncsu.edu/news/protect-and-serve-1.16514

"The Current Biodiversity Extinction Event: Scenarios for Mitigation and Recovery" http://www.pnas.org/content/98/10/5466.full

 "Contemporary Mass Extinction" http://journalofcosmology.com/Extinction104.html

"Human Population and Extinction" http://www.biologicaldiversity.org/programs/population_and_sustainability/extinction/