Identifying Environmental Hazards
Identifying Environmental Hazards
The study is designed to determine whether there is increases or decreases in the population of invasive species as well as ascertain the implications associated with the alteration of the population of the invasive species to the ecosystem as a whole.
Today, due to factors such as foreign travel, globalization, the increase in human population, and uncontrolled development patterns, the frequency and magnitude of introductions of non-native invasive species (NNIS) into native lands has grown at an alarming rate (Mooney & Cleland, 2001). Invasive species pose serious risks to the native ecosystems, threatening to change not only the existing natural ecological trajectories but also suppress the rare and endangered native species. They reduce the productivity of local flora and fauna species and biodiversity, and damage sensitive wildlife habitats (Mooney & Cleland, 2001). One such invasive species are the Zebra and Quagga Mussels (collectively known as dreissenid mussels) (Quigley, 2016). In the Great Lake Region, the Zebra (Dreissena polymorpha) and Quagga (Dreissena rostriformis bugensis) mussels are native and invasive (Great Lakes Environmental Research Laboratory, 2008). They represent an environmental and economic nuisance with the potential to damage equipment and infrastructure, affect water system reliability and quality, infest raw water conveyance systems, and harm ecosystems (Quigley, 2016).
The Zebra mussels are native to regions surrounding the Black, Caspian, and Azov seas while the Quagga are native to Ukraine (Great Lakes Environmental Research Laboratory, 2008). By the early 19th century due to travel, cargo, and shipping escapades in the transatlantic journey and widespread constructions of canal systems, the zebra and quagga mussels had spread to almost all major drainage systems in Europe. In America, the species were introduced via ballast waters in unladen cargo ships (Quigley, 2016). The repeated and unregulated dumping of ballast waters by ships travelling from Europe to North America brought more and more of the mussels to the States (Quigley, 2016). The construction of the St Lawrence Seaway that connected the open seas to the Great Lakes provided a path through which the mussels invaded the waters of the Great Lakes. The quagga mussel was first discovered in the Great Lakes in 1989 near Port Colborne, Lake Erie. After confirmation that the mussel was not local, the new species was named “Quagga mussel” after the “Quagga” – an extinct African relative of the Zebra (Great Lakes Environmental Research Laboratory, 2008).
Unlike the native Dreissena polymorpha, the Zebra and Quagga mussels are extremely tolerant to environmental resistance and thus have the greatest biotic potential in their newfound habitats (Great Lakes Environmental Research Laboratory, 2008). In the Great Lakes, for example, the prevailing environmental as well the biological offer optimal conditions for the growth and expansion of the invasive mussels for three main reasons. First, the environment of the region provides hardy and rocky substratum for their proper attachment. Second, the lakes have ideal summer warm temperatures, plentiful supply of nutrients, and favorable levels of salinity and PH. Third, unlike their native ecosystems, there is no effective predators, pathogens, or competition to keep their growth in check and regulate their numbers. Because of such factors, the Zebra and Quagga mussels have invaded and colonized regions frequently unoccupied by local species. Their continued expansion, however, has brought about significant changes and alteration of the original biological balance (Table 1).
The population of the Zebra and Quagga mussels will first increase and later decrease in number. This alteration in the number of the mussels will also affect the number of other organisms in the ecosystem. In other words, the number of producers will decrease when the number of mussels increases and increase when the population of mussels of decrease.
In the study, samples of six species and the mussels were collected and observed in an enclosed study environment. The number of each specimen were determined at specific intervals, calculated, and tabulated as shown in Table 1. The information from the table was then used to prove the validity of the hypothesis.
The study result shows that the hypothesis of the experiment was correct. The population of the mussels increased for some time and then declined. Similarly, the number of the other six species decreased as the number of the mussels increased but increased as the number of the mussels declined (Table 1).
In the course of the experiment, the study has indicated the mechanisms by which invasive species invade and evolve in response to their new environments. The study has also shown how the invasive species such as the mussels have the capacity to alter the biological trajectory of the native species which they interact.
Great Lakes Environmental Research Laboratory. (2008). Zebra & Quagga Mussel Research at NOAA’s Great Lakes Environmental Research Laboratory. Retrieved from National Oceanic and Atmospheric Administration (NOAA) website: http://www.glerl.noaa.gov/pubs/brochures/20ZMresearch.pdf
Mooney, H. A., & Cleland, E. E. (2001). The evolutionary impact of invasive species. Proceedings of the National Academy of Sciences, 98(10), 5446-5451. doi:10.1073/pnas.091093398
National Oceanic and Atmospheric Administration (NOAA). (2014, April 10). Small Mussels with Big Effects: Invasive Quagga Mussels Eat Away at Great Lakes Food Web. Retrieved May 2, 2016, from http://research.noaa.gov/InDepth/Features/CurrentFeature/TabId/728/ArtMID/1884/ArticleID/10527/Small-Mussels-with-Big-Effects-Invasive-Quagga-Mussels-Eat-Away-at-Great-Lakes-Food-Web.aspx
Quigley, M. (2016, January 8). quagga mussel (Dreissena rostriformis bugensis) - FactSheet. Retrieved May 2, 2016, from http://nas.er.usgs.gov/queries/factsheet.aspx?speciesid=95