The Invasion

                                                              

                                                    

     The quagga mussels inhabiting Arizona’s Lake Mead are causing a dramatic change in the lake’s ecosystem, making it the very definition of a disturbance.  The quagga mussels established themselves in Lake Mead in 1988, after somehow being brought over from Eurasia. This invasive species has the ability to rapidly reproduce. They push out the native species that inhabited the area before them, thereby breaking the natural balance of the lake’s trophic level, or food chain. The native species simply cannot compete with the quagga mussels for resources so they are forced to move. The mussels create this “Clear Water Effect” where they filter out particles that are food for many other species in the lake.  The removal of these particles also allow for sunlight to penetrate deeper into the ocean allowing for toxic algae to grow in the lake. Lastly, these mussels create a slime build up that clog pipes as well as fishnets. Since the arrival of the quagga mussel species in America there has been a reported economic loss of five billion dollars. 

     An invasive species seems to be a human caused ecosystem disturbance. There are many examples of the idea to prove this theory. The first example is Asian carp brought over to America and placed in a body of water in an attempt to try and control plant life there. It then turns out that the Asian carp reproduces rapidly, and eats 20-40% of their weight in food every day. Native fish are then pushed out of their usual areas and smaller fish are even being eaten. That changes the balance of the trophic level, thereby creating a completely new problem than the initial one. Humans are then forced to try and find a way to thin the numbers of this invasive species through fish catching festivals or by monitoring food shops for Asian carp “trafficking”. 

     For the second example we will now turn our attention to Yellowstone Park.  A little while after Yellowstone Park is established humans determine that there are too many wolves in the area. They then decide to kill of the wolf species in that area. This allowed for the elk population to rapidly grow. Their consumption of the plants in the area went up until other native species were consequently pushed out. Luckily, by the reintegration of wolves back into that ecosystem the natural balance of the food chain was able to be restored. Actually, new species such as coyotes and foxes began to populate the area. It seems that every time that humans tried to control a particular ecosystem by the integration of a new species, or the removal of a native one, a new, more detrimental problem arisen.

     When it comes to the quagga mussels and Asian carp situation it looks as if we may have to eventually act on a national scale. It seems that in both cases these species have the ability to rapidly expand their territory and strongly disrupt the natural ecosystem. By doing so they create an environment that is harmful to nature and in many ways harmful to us humans. If these species continue to find their ways to more and more valuable water sources in America these affects may spill over into the ecosystems on land as well. 

     Many species use rivers, ponds, and lakes as sources for food, including humans. Since these invasive species begin to create health issues for land animals, there is only a matter of time before they would start creating health problems for us.  If some or all of these invasive species need to be removed from the water, then we should be doing whatever we can as a nation to restore a the balance back to a healthy  ecosystem, and also contribute time and resources to stopping these type of happenings in the future.