Habitat loss stands as the biggest source of extinction today. Right next to it is the threat of invasive species. Demonstrated by the numerous examples in National Geographic’s Strange Days on Planet Earth documentary, exotic species are altering the compositions of the world’s ecosystems. What makes this otherwise natural phenomenon alarming is the rate at which invaders are introduced to new parts of the world and the rate at which species are phased out. The biotic background for evolution is accelerating at a pace determined by compounding number of species involved and increasing exchange rates. Competitive interactions lead to niche displacements and ultimately in many cases, extinction. In a study attempting to simulate the worst case scenario of invasions, the world is depicted as a supercontinent with no geographic barriers while retaining its abiotic characteristics such as climate and landscape. Massive extinction would predictably result, with species losses of 65.7% for land mammals, 47.6% for land birds, 35% for butterflies, and 70.5% for angiosperms. If current trends continue, our age will be seen as the sixth great extinction, making it comparable to the famous End Cretaceous extinction that ended the existence of dinosaurs.

A lot of times I ask myself whether the species mixing is inevitable, a product of our own movement, and whether all the attention put on the subject is worth it at all. I think it is our ethical responsibility to at least attempt species management, especially if endangerment of extinction is man-made.

The methods used to fight invasive species seem to have their trade offs. Local efforts to physically remove the invader is selective and inefficient. I think that the educational value of community involvement is the biggest plus; knowing how issues directly effects the people is the essence of good citizenship. Closely monitoring areas for invaders makes prevention for feasible and seems to be the most efficient method. I don’t quite know what the termite control method actually does.

http://www.pnas.org/content/98/10/5446.full

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VJ1-4CX6XXG-2&_user=38557&_coverDate=09%2F01%2F2004&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1457249298&_rerunOrigin=scholar.google&_acct=C000004358&_version=1&_urlVersion=0&_userid=38557&md5=21a00aef54349a33d894ef1754f4071d&searchtype=a

“Strange Days on Planet Earth” is a short documentary narrated Edward Norton about invasive species.  It highlights several invasive species such as water hyacinth, Nile perch, termites, and Miconia. The film also has an excellent general overview of invasive species.  The documentary skillfully illustrates the effects an invasive species can have on the invaded cosystem, economy, and health of local humans.  All aspects of invasive species are covered in the film.  It discusses how invasive species are introduced into a new environment, what advantages they have over native species, and how they can cause massive collateral damage.  For example, the termites that invaded the south (New Orleans in particular) were brought to the United States in crates (accidentally) from Japan following their surrender in World War II.  The termites had one significant advantage over the indigenous termites.  The Japanese termites burrowed above ground as well as below, while the native termites burrowed only underground.  This allowed the termites to invade large areas and significantly number the native species.  The resulting cost is tens of millions in property damage.

But financial costs aren’t the only adverse side effects invasive species can cause.  The Miconia invasion in Hawaii is destabilizing the soil of the islands as it pushes out native plants.  During heavy rains the shallow roots of the Miconia fails to hold the soil, often resulting in landslides.  The efforts to combat the Miconia invasion costs millions of dollars. Without local efforts, the Miconia would likely overwhelm local plant species and cause severe ecological repercussions.  However, the Water Hyacinth causes health problems as well as financial and ecological.  It chokes the shorelines of Lake Victoria which provides stagnant water for malaria ridden mosquitoes and other disease bearing creatures.

The documentary does an excellent job of discussing the general impact of invasive species and the potential harm they can cause if left unmolested.  Given the massive international shipping and trading industries, the spread of invasive species is likely to increase.  If the industries continue to grow but the efforts against invasive species does not, invasive species will become a global catastrophe.  The film postulates that once geographic barriers are removed, as many as two-thirds of the Earth’s species could be made extinct in a mass survival-of-the-fittest free for all.

I personally believe that “Strange Days on Planet Earth” is an excellent documentary.  It discusses every aspect of invasive species with plenty of depth.  It seems incredible how easy it is for invasive species to be transported accidentally.  All it takes is a few plants or animals to devastate an ecosystem and cost billions of dollars.  The film was also incredibly illuminating.  I  never thought of invasive species being such a major problem, but after just that short documentary I am aware of how serious it really is.  “Strange Days on Planet Earth” is well constructed and extremely informative.