Facing Extinction

The Fifth Mass Extinction

Once specie becomes extinct there is no way in bring it back, despite what Jurassic Park may have led you to believe. However you may be shocked to find out that species extinction is a very common and natural phenomenon. Natural extinctions occur at 1 per million species annually which accounts for the fact that 96% – 98% of all species that have ever lived on earth are now extinct. In addition the earth periodically suffers a mass extinction in which large numbers of species are wiped out in a short period of time, the last example being the dinosaurs. However, scientists have discovered that extinction rates are on the rising and have reached 100 – 1000 species per million per year, not to mention there are unrecorded species that go extinct even before we discover them. To put that number in perspective it can be compared to the last five mass extinctions. This is due to the fact that humans destroy habitant, introduce pesticides, and over consume resources such as lumber and fossil fuels which create greenhouse gases further endangering the planet. It is said that “…one-in-five mammals assessed, one-in-eight birds, one-in-three amphibians, and one-in-four corals…” are on the edge of extinction and will disappear if nothing is done to stop it.

Fender’s blue butterfly

This rare butterfly is now on the verge of extinction

Habitat destruction is one of, if not the most dangerous threats to endemic (native) species. Deforestation for farming and ranching and suburban sprawl (increase of suburb areas around a large city) are just two ways that we redirect land use for our own gain. This leads negatively to the outcomes of fauna (animals) and flora (plants) around us. One such example is the Fender’s blue butterfly. Thought to have become extinct in 1937 the Fender’s blue butterfly (Icaricia icarioides fenderi) was only rediscovered in 1989. The reason why this graceful insect almost faded out of existence was due to destruction of its highly specific habitat. Much of the wild grasslands of where the Fender’s blue thrived were systematically converted into farmland. A plantfound only in wild grasslands of the Central American prairies, the Kincaid’s lupine,

The Fender's Blue butterfly larva are born and feed on this vital plant

acts as the primary food source for Fender’s blue larva, and without the lupine the butterfly cannot survive. Approximately 0.1% of the butterfly’s original grassland habitat exists today. Conservation sites have been established but butterfly populations have been in decline since 2001 due to drought. With increasingly unstable climate change the last of the Fender’s blue butterfly may finally disappear.

Rachel Carson’s Silent Spring and the effects of DDT

Spraying DDT was a common sight in the 1950-1960 regardless of what health side effects it would have caused

Even at a young age Rachel Carson was passionate for nature. Having grown up on a farm, she was instilled with an admiration of wildlife that would reflect her writing and work as a marine biologist. After graduating from John Hopkins University and publishing numerous books about marine life, Rachel received a chilling letter from a friend. Her friend had discovered an alarming amount of bodies of neighbour birds around her property. The area had just been sprayed with DDT to kill misquotes, but it seems it was just as deadly to non-targeted species.  Carson immediately started writing what would be her greatest work, Silent Spring. The title comes from a poem by John Keats that describes a spring without the sounds of birds. Her book which became a bestseller was much debated by chemical production companies and scientist who debating its scientific integrity. At that time DDT was a common and viable source of pesticide which made agriculture more successful. It could also have been said that DDT reduced the chances of malaria (a deadly disease that claims thousands of lives) which uses misquotes as vectors (An organism that carries disease-causing microorganisms from one host to another) . The absence of DDT in some scientist

The concentration of DDT increases as the tropic (food) levels rise

eyes would be a technological step back. Soon the president at the time, J.F. Kennedy, appointed a team of scientist to determine the validity of Carson’s case and after their investigation DDT was banned in the United States. This example proves that there is a trade-off to human invention; what we think may be the only solution may have more catalytic effects elsewhere. The banning of DDT was only a precursor and changed the way the public viewed the environment (this was before the mainstream concern of greenhouse gases, climate change, global warming, and recycling).  Here is a more detailed video of Rachel Carson’s life.

With all the facts about climate change, mass extinction, and humans tampering with the natural balance, one may find the future bleak and apocalyptic. However this does not have to be the case. People like Rachel Carson have made a tremendous change for a better future. If more individuals were willing to speak up and spark controversy, the rate of extinction would diminish and species such as the Fender’s Blue butterfly might be able to be preserved for future generations.

Given the information above, please comment on what you think the US government should have done with respect to DDT and why. On one hand banning DDT reduces the deaths of many vital species and prevents unknown human risks. On the other hand, DDT enhances food production for an already starving world and decreases cases of malaria which in parts of the world have killed thousands.

(update)

In my opinion the American government did the right thing by banning the use of DDT. The conservation of species far out weighs the improved production of crops. With modern industrialized agriculture we increased grain productions five-folds in the past century without the use of DDT in Canada. Secondly the spread of DDT is not localized within insect species. This problem is magnified when doses of DDT become more potently concentrated as it is consumed with each increasing tropic level. This may end up affecting larger predatory animals ranging from small pets, aquatic life, predatory birds, and larger carnivorous mammals with lethal doses. By introducing this toxin into the environment, mankind is endangering the survival of all species on earth and with the effects of climate change can ultimately wipe out the planet’s biodiversity.

Food Chain

Although the use of DDT can aid in eliminating the spread of malaria, the disease can be treated with less threat to the mosquito population. Although there is no current cure for malaria there are treatments and preventative measures against it. In addition the extermination of misquotes as a species may deleteriously affect the delicate food chain leading extinction of other connected species (see food chain).

Current chemicals being released that provide a similar affect on climate and the environment include industrial gaseous waste and carbon emissions. The gaseous waste include nitrogenous and highly acidic compounds. These compounds when condensed fall back to earth and acidify bodies of water, eat away plant tissue and endanger species. They also act as aerosols that reflect sunlight away from the earths surface.  Carbon emissions are produced by the combustion of fuels such as coal, oil and bio-fuels. substances such as carbon dioxide and monoxide act as green house gases and cause global warming. This emissions sadly are by-products of important chemical industrial reactions required to produce manufactured goods. The production of toxic fumes can only be banned once society as a whole can either find alternative ways of production or can function without this process.