In-danger-ed: The Web of Life
Life abounds on Planet Earth. From the Arctic to the Amazon to the deepest depths of the seas, some 8 million species of creatures have figured out how to adapt and thrive. Together, they form an intricate web of competition, cooperation and co-existence that has been millennia in the making. Today, however, these creatures are at a crossroads not of their own choosing. Humankind has become the dominant presence on Earth, ushering in what is being called the Sixth Great Extinction period in Earth’s history. And the so-called Anthropocene Era not only brings the extinction of hundreds of species every year; those that remain are being stressed and drawn down, to the point that there are only half as many living creatures on Earth as there were just 45 years ago.
Why does it matter?
Why should we care that other living things are in danger of being lost to our planet? Some would say that these creatures have as much right to be here as we do. Others point to religious teachings that call us to “serve and protect” life on our planet. And there are the intangibles of wolves’ howls, birds’ brilliant plumage, the graceful lumbering of an elephant family across the Serengeti.
On a more practical level, pollinators help 30 percent of our fruit and nut crops thrive. Frogs and snakes keep down mosquito and rodent populations. Native communities and many of the rest of us depend on wild game for food. Man-eating tigers protect some of the last mangrove forests along coastal areas of India, which sequester carbon, stem erosion and combat rising sea levels. Fish are an important source of protein for half the world’s people. Wolves bring tourists to Denali; lions do the same for Maasai Mara, as do coral for Belize and moose for New England. As keystone predators, sharks keep a lid on skate and ray populations, not allowing them to over-eat their fav foods, shrimp and scallops (which some of the rest of us like). Scavengers give waste a second life. Ants, earthworms and bacteria enrich the soil, from which springs the plants that are the foundation of the food chain. Birds, one in eight species of which are in danger of extinction, may truly be canaries in the mine—harbingers of environmental threats to our own health.
Cause and Effect
First, the effect. As mentioned above, the population of living creatures on earth has fallen by half in the past 40 years. The USA has seen bird populations decline by 800 million in that period of time, with 230 species now facing threats to their survival. While some species of fish, plants and animals are rebounding from previous declines in the Rich World, this is in part due to increased protections and restoration of habitats, and in part a result of having outsourced our resource extraction to the Poor World, where steep drops in wildlife populations more than offset these gains.
The causes are many, with habitat loss leading the way. Whether forests cut for palm oil in Indonesia, or swamps giving way to sugarcane in the Everglades, or the latest housing development reaching farther into “undeveloped” land, humans are not good at sharing space with other living things. There is increasing international demand for palm oil, beef, soy and wood, fueling the illegal destruction of tropical forests at an alarming rate. And often “we know not what we do”—clearing land of “undesirables” such as milkweed plants unwittingly leads to the loss of creatures such as monarch butterflies, for which milkweed is an essential food and host for its eggs.
Over-harvesting also takes a toll. Two-thirds of global fish stocks are now considered over-fished. When roads are made into forested areas in Africa, animal populations plummet as local hunters clean out forests to supply urbanites’ longing for “bush meat".
A different kind of harvest is that done by housecats on the prowl. A recent Smithsonian report claimed that 1-3 billion birds and up to 15 billion small mammals are killed by let-loose and feral cats every year in the USA.
Yet another kind of over-harvesting is carried out by the world’s poachers and other illegal wildlife trade. Whether killing whales, elephants, rhinos or reintroduced wolves, capturing tropical birds and fish, or absconding with body parts thought to have medicinal properties, this $19 billion global industry further depletes already-threatened species.
Pollution is another cause of creatures’ demise. Runoff from mines, farms, industries, roads, and lawns kills stream life and creates Dead Zones in the world’s oceans and bays—400 at last count. The oceans also average46,000 pieces of plastic per square mile—a deadly hazard to marine life—some scientists say causing more death to living things than climate change. Pesticides increasingly threaten aquatic species, with 90 percent of US urban streams affected; pesticides also are responsible for the deaths of over 70 million birds in the US every year.
And the most insidious pollutant of all—greenhouse gases and the changes in the world’s climate they are causing. Over one-quarter of the world’s reptiles and amphibians are at risk of extinction by 2100 if present warming trends continue. The clock is ticking for moose, native fish are losing ground, darker colored insects are having to get outta town.
And even our good intentions go awry. Wind turbines installed to reduce climate change and thus abet living creatures kill nearly a million bats and as many as 300,000 birds a year in the USA. A simple adjustment in their off/on switch could fix this. However, coal-related eco-impacts kill many more than all other forms of energy production combined.
What to do
Sources: 2012 Living Planet Report, Greenpeace fisheries report, NYTimes report on threats to bats, Treehugger.org on Dead Zones, Bushmeat.org, Say No to Palm Oil, climate change and extinction, Trout Unlimited