Why Do We Need to Halt the Cascading Effect of Species Extinction?

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In the realm of ecology-related dangers we are facing, the loss of biodiversity has been deemed an even more significant threat than climate change. Half of Earth’s species will be at risk of extinction by the decade’s end. No matter how insignificant a species may seem, it plays an important role in its ecosystem and deserves to be preserved. In the face of this worsening crisis, the loss of species serves as a reminder that we are using Earth’s resources far beyond the limits of sustainability. We must work together to turn this alarming trend around. 

So what exactly is causing such a rapid pace of extinction? Human activity is definitely the leading cause of this issue. According to biologist Paul Ehrlich of Stanford University in California, “We want to build highways across the Serengeti to get more rare earth minerals for our cellphones. We grab all the fish from the sea, wreck the coral reefs and put carbon dioxide into the atmosphere. We have triggered a major extinction event.” Human activity can either directly or indirectly influence populations and lead to extinction. Exploitation, such as overhunting and overfishing, is the leading cause of the issue, accounting for 37% of extinctions globally. Sometimes we don’t recognize the consequences of our actions. According to a logistic growth curve, the population of an organism grows the fastest when it’s at half of its carrying capacity. As it approaches the carrying capacity, the increase slows down, and it goes the same when the population is extremely low. An incorrect approximation can also lead to overfishing, an example of which was the collapse of the northern Atlantic cod fishery in 1992. The second leading cause would be habitat change or degradation. This includes the more well-known threats such as global warming, ozone depletion, ocean acidification, and many more. Changes in temperature or the UV level are major alterations to the abiotic factors of an environment for a terrestrial ecosystem. Ocean acidification can also damage biodiversity since some organisms cannot obtain the nutrient or energy they need for survival. 

Another cause of the large-scale extinction is the artificial introduction of invasive species, which is a non-native population that tips the balance in an ecosystem. They compete with the native species for resources and usually do not have predators, allowing them to thrive beyond what the habitat can maintain. A well-known example is the spread of lionfish across the east coast of the United States. They are native to the Indo-Pacific oceanic region and likely got introduced to the east coast by unaware people dumping them into the ocean. A small amount can lead to a massive problem since these lionfish do not have a natural predator due to their venomous dorsal spines that warn off other organisms. Invasive species can be dealt with by introducing a predator into that area, but we must keep in mind that this can further disrupt the balance. Damaging the natural food web in an ecosystem can sometimes turn out to be an irreversible action, and now we will look at the consequences of the extinction of species.

Photograph by Neil Carthy, MyShot

Extinction can pose many threats to our world as a whole. The loss of biodiversity can be caused by the extinction of a species. Before the population of that organism can be replenished, a trophic cascade can occur. For example, if a predator becomes extinct, its prey will thrive, and that will impact the vegetation in that ecosystem. This can lead to habitat destruction due to the loss of plants and the toppling over of the whole food chain. According to Kelsey Wooddell, assistant director of the Earth Institute Center for Environmental Sustainability, “Even if it’s not a keystone species [a species that others in an ecosystem depend on], its loss will weaken the functionality of the entire ecosystem, which just makes it easier for that ecosystem to stop working.” Saving one species can mean saving its habitat and surrounding species. Nevertheless, even though it seems like losing an ecosystem can’t affect humans that much, the truth is that it really can. Damaged biodiversity can lead to deadly diseases and food shortages for us. We have to deal with the consequences of our own actions. 

There is another issue similar to extinction that is damaging our environment just as much: extirpation. Extirpation, also known as local extinction, is when a population disappears from a specific geographical location. It sounds less alarming than extinction since the species is not completely gone. Although they might still be present in other parts of the world, extirpation can lead to a decrease in genetic diversity and various other negative impacts. Extirpation can occur due to many forms of human impact, just like extinction. Habitat destruction, excessive hunting, and the introduction of invasive species can all lead to this issue. It is not a problem to be taken lightly since it can affect the ecosystem that the organism lived in, as well as the diversity of the species all over the world. 

Trophic Cascade (Author Ccarroll17)

All the species within an ecosystem are connected in one way or another. The extinction of a seemingly harmful population can potentially destroy a whole ecosystem that it’s part of. Our science world cannot determine all the complex relationships between organisms yet, but we are becoming more aware of the seriousness of our actions in the past few decades. However, with our new advancements in technology and awareness, we can make a difference – and hopefully, reverse the damage we’ve done. 

Works Cited:

  • Cho, Renee. “Why Endangered Species Matter.” State of the Planet, Columbia Climate School, 26 Mar. 2019, news.climate.columbia.edu/2019/03/26/endangered-species-matter/.
  • Editors, B. D. “Extirpation.” Biology Dictionary, 5 Apr. 2017, biologydictionary.net/extirpation/.
  • “Effects of Species Extinction on the Ecosystem.” Wild Life Risk, 29 Apr. 2020, wildliferisk.org/effects-of-species-extinction-on-the-ecosystem/.
  • National Geographic. “Invasive Species | National Geographic Society.” Education.nationalgeographic.org, 27 Sept. 2022, education.nationalgeographic.org/resource/invasive-species/.
  • “The World Counts.” Www.theworldcounts.com, www.theworldcounts.com/challenges/planet-earth/forests-and-deserts/species-extinction-rate.

This column was submitted by high school student Iris Wang. Student STEM Columns are submitted by high school or advanced middle school students who wish to share their passion for STEM. Students interested in submitting a column should email us at info@areteem.org.

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