Journal of Great Lakes Research. Vol. 35: 313-316, 2009.
Originally from Australia, South East Asia, and Africa, Daphnia lumholtzi arrived in southern United States in 1991. Since then, the population has begun to spread North and more recently have reached the Laurentian Great Lakes through ballast water discharge. The spread of this tropical species in the temperate great lakes has aroused the scientific community and led to nationwide studies.
Claudiu Tudorancea, Aquatic Bioservices, Kelly Bowen and Jocelyn Gerlofsma, Great Lakes Laboratory for Fisheries and Aquatic Sciences, worked together to research the spread of D. lumholtzi in the Great Lakes. They established 10 sampling stations and found D. lumholtzi in a warm, turbid, nutrient rich area near a sea wall. Other studies had similar results, and concluded that D. lumholtzi are prominent in areas with high temperatures during warmer seasons. From their data and trends of other studies, the team concluded that warm, shallow embayments are suitable for D. lumholtzi and that if climate change predictions are correct then D. lumholtzi spread will continue.
Bythotrephes longimanus, more commonly referred to as the spiny water flea, shown signs of disrupting the crustacean communities of the Great Lakes. Although many studies have shown the negative effects that the spiny water flea can cause on its environment, scientists still debate over whether or not these findings can truly be attributed to this invasive creature. This is why further research into the impacts caused by the spiny water flea still needs to be conducted.
Barbiero et al. (2009) have already presented a good example of the type of research necessary for proving the negative effects of the spiny water flea. Barbiero et al. (2009) analyzed samples collected by thirteen different research cruises in 1986 in Lake Erie. The data obtained from these samples were then compared against samples that were more recently collected. By doing this, Barbiero et al. (2009) were able to produce estimates of the spiny water flea’s impact on the crustacean community over a significant period of time by comparing estimates of cladocera production with estimates of flea consumption.
Barbiero, R.P., Rockwell, D.C. 2008. Changes in the Crustacean Communities of the Central Basin of Lake Erie during the First Full Year of the Bythotrephes longimanus Invasion. Journal of Great Lakes Research 34:109-121.
Amer. Zool. 36(3): 271-286 (1996)
In addition to the zebra mussel, the invasive quagga mussel has also established itself in the Laurentian Great Lakes in the past twenty years. Both of these mussels have been known to eat away at the native zoo plankton populations at alarmingly high rates.
Edward Mills and his colleagues at the Cornell Department of Natural Resources recorded data of the two species from the Great Lakes. Their research showed that the quagga mussels are more abundant in certain areas of the lake where the zebra mussels used to be dominant. The quagga mussels could possibly be better suited to the lakes’ conditions and could eventually out compete the zebra mussels. Mills and his colleagues are concerned about the possibility of the quagga mussel becoming the dominant mussel in the Great Lakes and the effects that would ensue from this change.
Brendon MH Larson argues that biologists utilizing militaristic and combative rhetoric to emphasize their arguments are actually hindering their ability to coherently get across the true effects of a particular invasive species. Larson believes that this type of attacking and berating writing style contributes to the development of an inaccurate interpretation of the effects of foreign species on a particular ecosystem. He also believes that this militaristic language undermines the validity of the scientific data presented can potentially lead to a social dilemma. One of Larson’s main points is that while combative rhetoric may spark the attention of a large audience at first, this sporadic drama will soon subside and in long term the issue of foreign invasion is forgotten without the passing of any remedial methods.
In my own literature review I was a “victim” of using militaristic rhetoric however, I disagree with Larson’s main argument. “This creature has proven that it has the potential to unravel the very fibers of the food web established in its habitat and thus poses as a severe threat to indigenous species of the lakes.” (Cafaro 2010) This quote was taken from my literature review and is in reference to the invasion of the spiny water flea into the Great Lakes. In my paper, I believe that utilizing diction that further stresses the negative effects of a particular invasive species will help to drive the message home. By using words that strike out to the audience, the message being portrayed will be left resonating in their minds and hopefully inspire further action to be taken. I agree with Larson in that people should not simply throw out combative terms merely for the sake of attracting attention, however I do believe that if used properly, militaristic diction can indeed draw a more substantial amount of focus to the issues being presented.
After spreading throughout Europe, Japan, and Australia, it is no secret that the New Zealand mud snails are invasive species. In North America, they have become particularly present in most major Western waterways, with the exception of the Great Lakes. Edward P. Levri and his team from Penn State collected samples at several different depths in Lake Erie to further explore the minute presence of the snails in the Great Lakes. He and his colleagues found three separate areas in Lake Erie where the mud snails had invaded. Overall, however, the findings were relatively modest. The scarcity of the mud snails in the lake can be attributed to depth they were found; it is very unlikely that they have been or will be transportated through recreational activities such as boating. Levri and his team stress that although further invasion is improbable, there is still the possibility that they can spread by dredging, the digging up of sediments, or even more introductions from Europe.
Journal of Great Lakes Research 3, 335-340 (2007)
Journal of Great Lakes Research 36(3): 540-547 (2010)
With the help of modern human transportation, invasive species can reach habitats that they never could before. The ballast water of ships carries multitudes of microorganisms that, when discharged into a new ecosystem, can disrupt the natural balance in that area. Experiments done in the Laurentian Great Lakes concluded that assemblage, staining, and observation was the most efficient way to evaluate the freshwater organism content in ballast discharge while other methods proved ineffective and unclear.
Euan D. Revie and his research team from the University of Minnesota Duluth tested multiple ballast water treatments, such as: enzyme digestion, flow cytometry, and multiple stains. A reliable process to test the densities of phytoplankton cells in the 10-50 micrometer range has yet to be found, and reliability was based on several factors. The methods were tested for precision of the organisms’ conditions at ballast water discharge, consistency of results in a given area, and practicality as well as speed of method during on-site projects.
Diversity and Distributions doi: 10.1111/j.1472-4642.2007.00434.x (2007)
In recent years, the Laurentian Great Lakes have been a destination for many invasive species. One of the most recent aliens to enter is the bloody red shrimp (Hemimysis anomala), which is native to the Black Sea. Many scientists wonder how these shrimp got to the United States.
Asta Audzijonyte, from the University of Helsinki, with a team from Finland and Austria, tracked the shrimp using mitochondrial DNA, the gene sequences found the the mitochondria of a cell. The shrimp found in the Great Lakes had most likely come from the Danube delta. The team were able to track the crustacean from the Danube delta, to the Danube River, through the Main-Danube canal, finally to the Rhine delta where the the shrimp could travel to the United States via the ballast water of Trans-Oceanic ships. With this method of tracking, the authors were able to figure out where the bloody red shrimp originated from.
Limnology and Oceanography 54, 757-769 (2009)
The invasive spiny water flea has entered the Great Lakes ecosystem and is damaging the ecosystem. This invasive specie has been known to eat large quantities of zoo plankton, and with its diet, the water flea takes away resources from other native species in the ecosystem.
Sophie Foster and her colleagues at the University of Toronto Graduate School conducted research on the Great Lakes’ ecosystems. They researched the abundance of the native fish speices in both invaded and non invaded lakes. The researchers discovered that the planktivorous fish were a lot less abundant in the invaded lakes than the non-invaded lakes. Foster and her team distinguished that the spiny water flea is not only destroying the zoo plankton population but also the populations of the fish that feast on the plankton.
In the past few decades, the Great Lakes have quickly become a major hot spot for invasive aquatic species. Of these invaders, the spiny water flea has proven itself to be quite destructive. Despite its tiny size, this creature has shown ample evidence that it can cause colossal damage to its habitat.
Professor Norman D. Yan and his colleagues at York University have measured and studied the populations of zooplankton in the Great lakes in order to better understand the extent of damage that the spiny water flea is causing. The team set out to visit Harp Lake, located in Lake Ontario, to collect samples of zooplankton. They found that the zooplankton community has been drastically reduced and assign the blame to the spiny water flea. Yan and his colleagues argue that if left unchecked, this invasive crustacean will slowly begin to unravel the fragile food web of the lakes.
Canadian Journal of Fisheries & Aquatic Sciences 58.12 (2001): 2341-2350.
The Sea Lamprey is an eel-like parasitic fish that latches onto other fish using its disk-shaped mouth. Using its horny teeth and abrasive tongue, the lamprey chews away the scales and skin of its hosts and consumes the blood and bodily fluids with the assistance of anticoagulants. Six out of seven host fish die from the large amount of blood lost. The Sea Lamprey did not become an exotic species until the construction of canals bridged it from the Atlantic Ocean to the Great Lakes. In the Great Lakes, the Sea Lamprey had no natural predators, allowing it to quickly multiply and devastate the lake trout, salmon, rainbow trout, brown trout, whitefish, yellow perch, burbot, walleye, and catfish stocks; fishing industries suffered naturally. The Great Lakes Fishery Commission, Fisheries and Oceans Canada, and the U.S. Fish & Wildlife Service investigated the invasion and devised several methods of population control. One relatively expensive treatment is a lampricide called TFM, which kills lamprey immatures with little known effect on other wildlife and humans. Lower cost alternatives include the use of selective barriers, traps, and sterile male lampreys; sterile males compete with fertile ones, ultimately reducing the number of females fertilized. Though these methods have not and can not completely rid the Great Lakes of the Sea Lamprey, they have been tremendously successful at lowering the population enough to allow fisheries to thrive again.
I see the Sea Lamprey story as a prime example of how invasive specie problems arise and how they can be resolved. The construction of canals is only one way which geographic barriers all around the world are nullified. In this case it is Niagra Falls. Cleaning up the mess was made possible by the united efforts of all those effected and the foresight to recognize the high returns gained form such an investment. My own firsthand contact with his organism was marked with immediate revulsion and fascination, which has intensified with more research. There are some things I want to know about the remedy. Exactly how aggressively were these tactics implemented? Since the population was already out of lag phase, how were they curbed away from exponential growth? I am also curious to know how important each of the of the tactics were to achieving the single goal.