Alien Invaders

Matt Altstiel
4/20/05
BioGeog

Attack of the Alien Invaders

The March 2005 National Geographic Article entitled “Attack of the Alien Invaders,” sheds light on one of the largest ecological problems threatening native wildlife in the world today. The author even refers to the phenomenon of non-native invasive species spreading to new areas as a “giant biology experiment with no one in charge, (McGrath 96). While invasive species are not a new occurrence, the rate of spread and the negative economic impact of these dangerous new plants and animals is. Each year the United States loses more than “140 Billion dollars to invasive species,” (McGrath 98). The increased rate of spread of these non-native species, whether intentional or unintentional is partially explained by three factors: more widespread and faster transfer of goods, the release of ballast water in different ports and harbors, and the emergence of a billion dollar global exotic pet, nursery specie, and Aquarium industry. One of these species, the Red Eared Slider Turtle, has spread from North America to Europe and Asia, “devouring native frogs, mollusks and even birds,” and threatening traditional wetland environments. These and other species have been “responsible for an extraordinary restructuring of wildlife around the planet,” (McGrath 102).

However governments, finally realizing the threat of non-native species and their ecological and financial impact have begun taking steps towards limiting the growth of existing invasive species, and preventing the emergence of new species. One of these methods is bio-control, a method which has yielded some impressive results but some utters failures as well. Bio-control fights the spread of invasive species by counteracting it with another species that feeds upon it. Many times bio-control can be effective with a minimum impact upon the environment because it does not use potentially polluting poisons and pesticides. However, there is often no guarantee of success and certain elements present in nature may limit the effectiveness of bio-control. Also, as a solution, bio-control is very expensive and often results in the introduction of one invasive species to control another.

Another problem that requires a viable solution is the increased spread of invasive marine life that comes from further and further away. Often these marine species enter ships as they take on water, as ballast to balance the ship. Since ships are constantly moving around the world because of international travel, there can be many species coming along for the ride within a single ship. When ships reach their destination in ports across the world, they dump out the ballast water which often contains invasive species. This process allows marine invasive species to spread exponentially quicker than they would have otherwise done. Devastating new species have reached bodies of water that contain no natural predators to stop the spread of invasives and the result can be catastrophic on the marine eco systems. The Zebra Mussel that has decimated fish populations across the Great Lakes is a prime example. Originally from the lakes and bodies of water of Eurasia, the Zebra Mussel made its way to Lake Michigan aboard a ship in the late 1980’s. Since then, Zebra Mussels have clogged pipes leading to infrastructural problems, have depleted the lake of oxygen, and killed off fish and other native mussels by consuming the same food. Several countries have taken steps to prevent similar situations such as requiring cargo ships to release ballast water before entering ports, but clearly more needs to be done.

While some alien species are beneficial and produced positive outcomes, all invasive species must be limited. One can never know when a potentially beneficial species will spread and eventually become and invasive pest species. Combating the spread of all invasive species requires a change in attitudes, and a change in policy. The article uses the phrase, “foolish and unforgivable,” if one sits back and watches ecosystems change forever. One must take the time to learn which species are invasive, and then as a local task force, go into the wild and remove and destroy native species. Such efforts of a population volunteering only once a month or week would be significant improvements and quite effective. Similarly, governments have the responsibility to prevent invasive species like Australia has, and by that is meant, publishing not a list of invasive species that must be kept out, but rather a list of organisms that may be brought in. Ballast must not be dumped in ports, and preventive measures must be put into place. Where invasive species already exist, bio-control coupled with herbicides and pest controlling agents should be used. A lot may be done to prevent the spread of invasive species; however it requires the persistent effort of the individual and the state. The author for one will find out about programs in the local area to help combat the problem of invasive species. After all, invasive species not only threaten our ecosystems, but they threaten our livelihoods and way of life.