5 Ways Humans Are Unraveling the Web of Life

The profound impact of The Silent Spring by Rachel Carson generated waves. Carson’s novel marked a turning point for public awareness of human-caused environmental harm in 1962. Moreover, decades after Carson’s novel, we find history repeating itself as we are faced with another catastrophic decline. While her novel focused on the chemical assault against wildlife, the threats of today extend even further.

Whether deliberate or unintentional, our actions have contributed to the decline of many wildlife species. Some species, like vultures, are killed simply for being unappealing, regardless of the ecosystem services they provide. According to the WWF Living Planet Report 2022, monitored populations of mammals, birds, amphibians, reptiles, and fish have declined by around 73% between 1970 and 2020, largely as a result of human actions and the neglect and degradation of key ecosystems. Follow along while I detail how humans have fueled this decline and what, if anything, can be done about it.

1. Habitat Loss and Degradation

Numerous human activities like deforestation, urbanization, and agriculture have led to the destruction and fragmentation of natural habitats. These activities reduce or destroy the resources and ecosystems available for wildlife. Habitat fragmentation is the division of a once continuous habitat into smaller and more isolated patches. The division of habitats can significantly reduce genetic diversity by encouraging inbreeding through the isolation of habitats.

Habitat fragmentation can occur intrinsically from natural disasters, but its occurrence has increased due to human activities. The deterioration of an environment is defined as the damage or changes to a once-sustained environment. These factors are among the leading causes of local extinctions. Urbanization leads to the disappearance of natural habitats, forcing many animals to adapt to urban areas. Though some organisms have found a way to amicably coexist in urbanized environments, it is difficult to assess their longevity in these spaces.

2. Pollution

Ever used a mercury thermometer? What was once used commonly in lab practices and households everywhere actually contains a leading chemical pollutant: mercury. Mercury is a naturally occurring toxic metal sourced from volcanoes, wildfires, and the natural weathering of rocks. From power plants burning coal to mercury-containing products, humans have increased the levels of mercury in our environment. Activities like waste incineration and electricity production also play a part in increasing mercury levels.

Humans are responsible for approximately two-thirds of the mercury emissions to the atmosphere. When mercury levels increase, so does its ability to leak into our ecosystems and environments. As a recent example, high levels of mercury contamination were found in alligators of the Okefenokee Swamp in southern Georgia. This contamination is likely to have come from the heavy metal pollutants in the region. What is even more alarming is that younger alligators had high mercury levels, suggesting the mothers are passing mercury down to their offspring. Mercury is not only a pollutant of wildlife, but this toxic metal can cause significant damage to humans as well. Humans who interact with mercury can suffer injuries to their brain, lungs, liver, and heart, and in some extreme cases, mercury poisoning can be fatal.

3. Climate Change

Rising temperatures, sea levels, and changes in weather patterns are dismantling ecosystems. With global warming effects increasing, species are losing the ability to adapt to these conditions and survive. Since about 1850, the Earth has warmed about 2 degrees Fahrenheit. This may not sound like much, but this increase has contributed to an increase in wildfires, habitat loss and degradation, and exposure to extreme weather events. Climate change can destabilize the balance between wildlife and their ecosystems. As an example, bloom patterns can shift for insects. Since insects typically ime their emergence and are active around host plant bloom times, this can be detrimental for their populations.

4. Overexploitation of Resources

Deforestation, unsustainable hunting and fishing, and poor agricultural practices can lead to the depletion of wildlife populations and the loss of biodiversity. Monoculture plots, slash and burn farming, and other unsustainable agricultural practices leech the soil of its nutrients and make it unviable for native plants and insects. And though our demand for food increases with the world population, roughly a third of the world’s food is wasted (approximately 1.3 billion tons of food a year).

Exploitation of organisms like plants, birds, invertebrates, mammals, amphibians, fish, and other aquatic species is another common thread in wildlife decline. Many of these organisms are hunted and collected for sport, fur, their skins, or food. Others are put into the pet trade or used in medicine. The issue with the collection and harvesting of these organisms is that it is done at a rate at which they cannot be replenished.

Probably one of the biggest exploitations occurs every day in the tropical rainforest. Even though tropical regions hold most of the world’s biodiversity, they only make up a small portion of the planet. Tropical regions also experience the highest rate of deforestation. Heartbreakingly, when these resplendent ecosystems disappear, so do their treasures in biodiversity. This is extremely concerning as tropical forests play a large role in carbon storage and water cycling. As if that weren’t enough, rainforests are homes to many ancestral territories, depending on the forest for their survival.

5. Invasive Species

Another destroyer of wildlife and ecosystems includes non-native species or invasives. Invasive species compete with natives and threaten their survival. Non-native species are usually introduced by humans and can be plants, animals, fungi, or bacteria. Species that are native can become invasive when they grow to an uncontrollable amount.

Typically, species that are invasive lack natural predators to keep them in check, which can make them surpass native populations. In other cases, they are able to adapt to their environment quickly and better than native populations. Below are defined some of the most invasive species in the nation.

Domestic Cats (Felis catus)

As much as I adore my quirky, cute, black cat, she is a non-native and invasive species. Cats moved into the Americas and established themselves very quickly as predators. Cats contribute to the extinction of more than 60 species of birds, mammals, and reptiles.

European Starlings (Strunus vulgaris)

These beautiful spotted birds look like they are kissed with gold dust from afar, but they wreak havoc where they land. Starlings can destroy crops and contribute to the spread of various diseases to livestock, humans, and other organisms. These birds are also violent towards other native species and have been documented destroying other nests and pecking holes in eggs laid by other birds.

Wild hog (Sus scrofa – feral)

These creatures escaped domestication and launched a full-scale rampage. Wild hogs compete with other wildlife forms and damage plants and crops. Not to mention, they carry a cocktail of diseases that they can transmit to humans, livestock, and other organisms.

Where We Go From Here

Much of our planet is facing substantial decline. According to a 2023 NatureServe report, in the United States, 34% of plant species, 40% of animal species, and 41% of ecosystems are at risk of extinction or collapse. And unfortunately, many important species are not the focus and poster children like the monarch butterfly, and honeybees take over conservation movements. What about the rusty patch bumblebee, the shevaroy stilt bugs, and the shevaroy hills earth snake? These are all vital and important species in their own ways.

The story of wildlife decline is unraveling all around us, with every species and ecosystem lost being a thread pulled from a bigger tapestry: one of life. The biggest thing we can do is continue to act. Support the local conservation groups, continue to plant native species, reduce pesticide use, and maybe keep your cat indoors. Voting for science-based environmental policy and learning the species around you, and standing ten toes down for them is important. Conservation is more than the animals; it’s about the systems that sustain life itself, including us. Try to remember our future depends on how urgently and deeply we choose to care.

The post 5 Ways Humans Are Unraveling the Web of Life appeared first on A-Z Animals.