Biodiversity is crucial in any ecosystem. It provides an environmentally sustainable life for the current and future generations. However, increasing human populations bring about various biodiversity threats.
This article outlines five major threats. These threats create a biodiversity crisis, leading to the extinction of nature as we know it. We will also explore means of preserving nature and from human activity.
Related Read: Conservation Strategies.
What is Biodiversity?
Biodiversity refers to all life forms on earth. It is animals, plants, fungi, and microorganisms that make up nature. Biodiversity doesn’t exist on its own. Individual species support each other. They work together in ecosystems like an intricate web to maintain balance.
5 Threats to Biodiversity
Threats to biodiversity are external factors that disrupt the intricate balance of biodiversity. These threats often trigger a biodiversity crisis. Here are five threats to biodiversity:
1. Habitat loss
One of the biggest threats to biodiversity is habitat loss. Animal species have low survival rates outside their natural habitats. They have no access to shelter from natural weather conditions, disasters, predators, and human activities.
There are three types of habitat loss. First, habitat destruction refers to the destruction of a natural habitat through human activities. These activities include cutting down trees, filling wetlands, mowing, and dredging rivers.
Second, habitat fragmentation refers to the division of wildlife's natural habitat. When fragments become smaller, it will be harder for animal species to survive. Habitat fragmentation happens due to urban development of roads, dams, and water diversions.
The third form of habitat loss is habitat degradation. It occurs when the ecosystem experiences disruption because of pollution, invasive species, or natural disasters. A degraded habitat cannot support wildlife, thus increasing the extinction risk of many species.
Habitat loss, a major threat to biodiversity, has many causes. Most of these causes are because of human activities and our need to develop urban areas and natural resources.
Many species lost their habitat due to the creation of croplands for extensive farming. Even today, conservation lands are turning into croplands for commercial plant and animal farming. We also convert wildlife areas into housing developments, roads, parks, offices, and other urban infrastructures.
The freshwater environment also experiences habitat loss. We release untreated sewage, pesticides, fertilizers, and other waste into freshwater sources. These pollutants contaminate marine ecosystems, kill lifeforms, and make them uninhabitable.
Over-exploitation is another threat to biodiversity. It refers to the excess consumption of natural resources by one species, which affects others.
We often exploit terrestrial animals as sources of food, clothing, jewelry, medicine, and pets. For instance, we often remove turtles, birds, and amphibians from their natural world for the pet trade. We harvest pangolins for their scales and meat, while we poach elephants and rhinos for their valuable ivory and horns.
Close to 30% of the bird population is near extinction due to overhunting. Certain species, like parrots, pigeons, and pheasants, are hunted for sport and entertainment. The Carolina parakeet parrot was once the only parrot species in the U.S., but humans hunted it to extinction early in the last century for food, to protect crops, and for its feathers.
Also, the fishing industry has become more industrialized, given the increase in the global demand for seafood. The fishing industry takes more fish from oceans and lakes than necessary. The populations of unique fish species like tuna, whitefish, swordfish, and cod have reduced drastically.
Overfishing has caused whitefish, walleye, and sturgeon populations in the Great Lakes to decline. Also, we remove freshwater species from their habitat and keep them in aquariums for entertainment2.
The overexploitation of animals causes an imbalance in the ecosystem services. A perfect example is the wolves of Yellowstone Park. Hunters targeted the wolves around the areas of Yellowstone Park and hunted them to near extinction.
The wolves were under the Endangered Species Act in 1973. However, the absence of the apex predator, which maintains the balance of the ecosystem, has caused the overpopulation of elk and other prey species. They overgrazed the lands, eliminating habitat for many species and reducing the quality of local waterways.
3. Introduction of invasive species
The introduction of alien species threatens biodiversity to a great extent. This threat to biodiversity could be diseases, plants, organisms, or animals introduced into the ecosystems through trade, travel, and agricultural practices.
They are any type of wildlife species not native to an ecosystem and cause harm. Invasive species harm natural resources and threaten biodiversity and even the local economy. We also call species that reproduce rapidly and spread aggressively, with the potential to cause harm to the environment.
Some examples of alien species in terrestrial and aquatic ecosystems are:
- Lionfish are in the Atlantic, Gulf of Mexico, and Caribbean waters. Lionfish harm the native coral reef ecosystems. They prey on herbivores that consume algae. It disrupts the food chain, promoting algae growth to the detriment of coral reefs.
- Feral pigs are invasive species that threaten biodiversity in various ways. They compete with native species for acorns and other food sources. Feral pigs eat almost anything, including pigs. They also spread diseases like brucellosis.
- Cogongrass, an Asian plant, is one of the major threats to native plants in the United States. Native species can't eat cogongrass plants as they offer no nutritional value. They also increase the risk of wildfires because they burn faster than native plants.
- European green crabs compete with the native species in San Francisco Bay for food and shelter. They threaten the commercial fishing industry by eating shellfish in massive quantities.
Alien species contribute to biodiversity loss by reducing food and shelter sources. They reduce the light, moisture, nutrients, and space available to plants. Also, they reduce the forage potential for birds, insects, and other wildlife. Eventually, they end up replacing the native wildlife of the ecosystem if we do not take care.
4. Environmental Pollution
Environmental pollution is one of the top threats to biodiversity. Human history shows the various ways we pollute the environment. There’s water, land, noise, and air pollution. Environmental pollution leads to an enormous threat to biodiversity, climate change, and global warming.
Air pollution refers to the release of pollutants and contaminants into the atmosphere. The majority of these pollutants come from energy use and production. To produce energy, we burn fossil fuels. Burning fossil fuels releases harmful greenhouse gasses and chemicals into the air. These gasses damage the ozone layer by trapping heat in the atmosphere.
It threatens biodiversity and human health. Research shows that 4.5 million deaths occurred in 2019 because of outdoor atmospheric pollution, and 2.2 million died from indoor atmospheric pollution1. Other causes of air pollution are transportation and vehicle emissions, harmful substances released during disasters like wildfires, volatile organic compounds, and particulate matter.
Ground-level ozone damages crops, plants, and forests by reducing growth levels and harvest yields and affecting ecosystem services. Air pollutants like nitrogen oxides and ammonia degrade ecosystems, especially water bodies. Nitrogen oxides entering water bodies create excessive amounts of nitrogen, contributing to a process known as eutrophication.
Eutrophication is a process whereby excess nutrients increase the algae’s growth rate and reduce oxygen in the water. The lack of oxygen in water is terrible for marine mammals and other organisms.
It promotes the loss of species that rely on oxygen in water and encourages species that can thrive in ecosystems with high nitrogen levels. It also changes the chemical composition of lakes, rivers, and oceans through acidification. The acidification of an ecosystem destroys it and the wildlife residing in/on it.
Read more: Air Pollution Facts.
Land & water pollution
We often forget that the soil beneath our feet is another form of biodiversity. The soil contains various life forms, ranging from tiny organisms to earthworms and fungi. The soil stores nutrients that support plants’ growth and survival.
The use of agricultural fertilizers and pesticides, plastic waste, oil spills, and heavy metal waste are the major causes of biodiversity loss. We release lots of pollutants from industry and transportation activities. These pollutants travel deep into the soil fauna, disrupting the ecosystem and destroying the wildlife above ground.
Fertilizers help nourish plants and improve their growth rates. However, surplus fertilizer enters the soil and causes more problems. Excess nitrogen in the soil leads to excessive plant and algae growth.
It also pollutes lakes and rivers. Nitrogen in water sources reduces the oxygen levels, harming animals and plant species in the water. Other chemicals are released into the environment through our activities, especially plastic and animal agriculture waste.
We also pollute water and land through mining activities. Mining natural resources like oil, minerals, and rocks creates a runoff situation. Metals and chemicals from these mining operations contaminate nearby water sources and land.
Land and water pollution reduces crop growth because it disrupts soil productivity. Water and food become contaminated, causing health problems for the wildlife and human population. In the long run, interaction between wildlife species and polluted environments eventually leads to their demise.
Noise pollution is another one of the threats to biodiversity, especially to the aquatic ecosystem. Humans are very noisy. A lot of the activities we engage in produce noise. However, many people don’t know how noise affects biodiversity and the environment.
Noise pollution is problematic because it disrupts information transmission among animals, especially when the noise produced is the same frequency animals use to communicate. Sometimes, the noise frequency from noise pollution can overpower animal sound frequencies.
It stresses animals and induces stress-related diseases. It also has the potential to reduce their population. Noise pollution threatens the survival of over 100 species. It affects courtship behaviors, causing birds to produce fewer eggs and fewer birds reaching the reproductive age.
It reduces the quality of wildlife habitat, causing animals to relocate to new habitats. Also, the noise changes animals' foraging patterns. For instance, marine mammals avoid a feeding area because of ship noises. Noise from commercial vessel traffic, seismic surveys, military sonar, and oil and gas exploration also causes beach strandings and collisions because it disorients aquatic animals.
5. Climate Change
Climate change refers to changes in temperature and weather patterns because of human activities. It is one of the top threats to biodiversity. Climate change is responsible for mass extinctions, changes in wildlife location and species richness, a decline in ecosystem services, and a rise in animal and plant diseases.
Climate change occurs because of an increase in greenhouse gas emissions. There has been a steady increase in greenhouse gasses from our activities. Greenhouse gases are carbon dioxide (76%), methane (16%), and nitrous oxide (2%).
The accumulation of carbon dioxide traps heat in the atmosphere and sends it back to us. We emit tons of greenhouse gasses by burning fossil fuels for energy production and manufacturing. Another cause of climate change is deforestation. Deforestation reduces the amount of trees available to sequester carbon from the atmosphere.
Climate change is a threat to biodiversity because it accelerates the extinction of wildlife species. The sea levels rise within a few years of climate change. It is difficult to analyze how much of a biodiversity crisis occurs because of climate change since other factors contribute to biodiversity loss.
However, evidence suggests the increase in temperature affects plants and animals. Wildlife moves to higher altitudes in search of cooler temperatures. Some species can't survive the unpredictable temperatures and eventually become extinct.
European birds change their breeding time, migration pattern, and species distribution patterns because of climate change. Studies show that climate change affects the reproductive abilities of species. It also affects plants’ flowering and fruiting patterns.
The marine ecosystem is the most affected. Corals are highly sensitive to heat and acid. An increase in water temperature will trigger the expulsion of the symbiotic algae from their tissues, leading to their bleaching. Coral reefs die when the bleaching lasts for several weeks.
How To Prevent Biodiversity Loss?
We should learn ways to protect biodiversity from current and future threats. Human activity is the primary cause of the biodiversity crisis. So, we need to take steps to ensure wildlife ecosystems are safe. Here are some ways to protect biodiversity:
- Raise awareness. Educating other people on the impacts of their activities on the environment goes a long way in preserving biodiversity. Learn as much as you can about nature and share your knowledge.
- Identify locations and threats to endangered biodiversity near you. Leave crucial wildlife habitats undisturbed, eliminate threats where possible, and leave the natural areas undisturbed.
- Watch your pet’s impact on biodiversity. Pets like cats are natural predators. They prey on small native species like birds.
- Maintain wetlands by conserving water and reducing irrigation. Don’t drain water bodies on your property unless it is necessary.
- Keep vehicles on main roads to reduce the spread of weeds and the disturbance to wildlife. Also, remove and control weeds on your property carefully. If possible, avoid using pesticides.
- If you must use pesticides, use natural products and methods to remove pests. Use pesticides with minimal residual effects, like insecticidal soaps, pyrethrins, and dormant oil sprays.
- The government should construct fences to protect endangered areas from the public population.
- Reduce carbon footprint by avoiding food waste, thrifting, and many more.
- Farmers should manage livestock grazing to prevent overgrazing.
- Protect old forests and trees because they usually house nest cavities for many species. It also gives room for new forest growth.
- Encourage and support local government initiatives and set up programs towards preserving biodiversity.
It is up to us to take conservation actions that protect biodiversity. Protecting biodiversity is simple as long as we know how our actions affect various life forms. Nature is beautiful. It sustains us. Let us prevent the biodiversity crisis in any way we can.