In 2016, more than 20 species made it to the extinction list. The next year, in 2017 it was more than five. In 2018 it was three. And so far 2019 has added one more to that list.
We know that species are going extinct at an alarming rate. Several times throughout the year we have seen headlines about the last of a kind dying. But that tends to feel a bit foreign, like it’s somebody else’s baby because we assume that it’s happening in tropical rainforests or in an African savanna. But what about extinction in the United States?
We’ve covered the rapid global decline in biodiversity before. In this post, we’re taking a closer look at the local consequences. We’re zooming in on…
The silent death of American wildlife
We tend to think of endangered species like polar bears, pandas, or other exotic and photogenic animals. But what about those in our own backyards?
As of February 2018, the United States has more than 1,300 endangered or threatened species.
This includes 94 species of mammals, 36 species of amphibians, 46 species of reptiles, more than 108 endangered arthropods and at least 167 species of fish. We havn’t even brushed on clams, corals, plants, or fungi, but you can look them up here.
These can feel like arbitrary numbers, as most of us don’t have any idea how many species of animals there are in the U.S. The International Union for Conservation of Nature (IUCN) clarifies this in an alarming way.
“The IUCN classiﬁes 18 percent of all remaining animal species and 30 percent of all remaining plant species in the United States as threatened.”- Center for American Progress
How the heck did we get to a point where 18% of the animals in our country, and 31% of the plants, are at risk of extinction?
The short answer is human activity, but as with most subjects, this covers a range of different and often intertwined causes. Here are the most prominent causes (we don’t have a lot of poaching in the U.S.):
Overexploitation is not a new concept.
In North America, extinction of large mammals set in long before the Mayflower went to shore. As early as 8500 BCE, the American mastodon that had roamed the North American prairies died out.
So did several species of bison, mammoths, and even a sloth.
And all that occurred between 8500 BCE and 2000 BCE.
Since Europeans started settling in North America, overexploitation has been a lead cause of animal extinction in this region. Among the now gone species are the…
And these are just land mammals.
In the 1970s and 1980s, the Atlantic cod stocks were severely overexploited, leading to their abrupt collapse in 1992. International waters are of course complicated in terms of regulation, but the freshwater fish populations in North America have also dwindled.
As of 2012, 39 species of freshwater fish (3.2% of North America’s freshwater fish population) and 18 subspecies had disappeared over the past century.
Habitat destruction and degradation
As of 2016, more than 44% of the area of the United States is classified as farmland. Whenever wilderness is converted to farmland, cities, highways, strip malls, or other human habitats, biodiversity is put under strain. Less breathing ground, fewer food resources, and more noise makes survival a hard game to play.
Bumblebees are one of the species hit hardest by habitat loss. They, and other pollinators, are vital for our food production.
That in combination with fragmentation, climate change, and pesticides, is making it harder to bumble.
—Like we said, lots of different factors are at play here.
Yep, we still have some ground to cover. According to The United Nations Economic Commission for Europe (UNECE);
“Ecosystems are impacted by air pollution, particularly sulphur and nitrogen emissions, and ground-level ozone as it affects their ability to function and grow. Emissions of both sulphur dioxide and nitrogen oxides deposit in water, on vegetation and on soils as “acid rain”, thereby increasing their acidity with adverse effects on flora and fauna.”— UNECE
These added nitrogen oxides cause algal blooms in water bodies, which results in hypoxia (a lack of oxygen).
Yeah, it really sucks.
The good news, however, is that trees and other vegetation absorb these pollutants, and therefore help to improve air quality.
Introduction of exotic invasive species
Though this sounds like a cool, sci-fi movie, where aliens descend on earth, the truth is more grim.
An invasive species is a species that is not native to a specific location.
The new species, be it plant, fungi, animal, or other, has a tendency to spread and cause damage to the environment.
One example is the hemlock woolly adelgid. Coming all the way from Asia, this invasive insect infested hemlock trees, killing most of them. In some parts of the Eastern United States, it is estimated that up to 80% of hemlock trees are dead because of the hemlock woolly adelgid.
Another example is the blue gum eucalyptus in California (see photo). Non-native to the area, it’s dry bark poses a fire hazard,and serve as a poor habitat for native spices.
In the U.S., invasive species cost an estimated $120 billion per year! This is due to costly control methods and the loss of environmental resources.
As if invasive species weren’t bad enough, it turns out that climate change makes the situation even worse!
“IAS [(invasive alien species)] are compounded by climate change. Climate change facilitates the spread and establishment of many alien species and creates new opportunities for them to become invasive.” — International Union for Conservation of Nature (IUCN)
Global warming is changing habitats and limiting food supply, making it too warm for certain species to survive. In January 2019, one single heat wave killed 1/3 of all flying foxes in Australia. Not to mention the extreme coral bleaching. Australia is the first to be hit, but American corals are under pressure as well.
Continuing the tragedy down under, in February 2019, Australia became the first nation to suffer a climate change-driven extinction of a mammal. The mosaic-tailed rat.
So that was the bad news.
But don’t worry, we have good news for you as well.
All of the above problems can be fought with one weapon:
Environmental conservation, preservation, and reforestation all counteract the negative effects of the above issues. They do so by ensuring adequate habitats for a number of species.
From prairies to water bodies, reserving land area for natural preservation also prevents overexploitation and gives the natural stock a chance to recover.
By preventing more habitat loss, species under pressure are given the space to breed and replenish their numbers.
In short, environmental conservation gives biodiversity a chance to rebuild itself. We’ll be going into more detail in a later post.
For now, you can read about how conversation, in addition to protecting wildlife, also helps fight climate change and can create jobs.