Posts Tagged “invasive species”
Elser from Arizona State University and his team conducted a study examining the distribution and competitive effects of the invasive zooplankton Daphnia lumholtzi in Arizona. First detected in Texas in 1990, this species indigenous to Africa, Australia, and India has spread throughout the midwestern and southern United States.
Elser conducted a field sampling of 12 reservoirs in central Arizona and a competition experiment involving water from Canyon Lake. The samplings demonstrated that D lumholtzi was dispersed across central Arizona in various watersheds, some with a greater percentage of the exotic zooplankton than others (ranging from none to more than the native species). This proves the persistence of this specie’s invasion in Arizona. The competition experiments found that the production of both species (D lumholtzi and native D pulex) decreased when both were present at the lake. Also, D lumholtzi reduced total zooplankton production. Therefore, communities dominated by D lumholtzi are expected to be less fertile and retain lower biomass.
Research on this detrimental species will continue because it impacts plankton communities and fish production since their spination renders them inedible.
Resource: Journal of the Arizona-Nevada Academy of Science Vol. 34(2): pp 89-94. (2002)
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Ballast water is used by cargo ships to help stabilize the ship and help maneuverability during long voyages. Generally, ships intake ballast water while in port, and release it once they’ve reached the destination. During this process, the sediment and everything else in the water is released into the port along with it. We now know that this is a very common pathway for aquatic invasive species to spread across the globe and establish themselves in new habitats. The introduced species can range from microscopic zooplankton to animals like crabs and mussels, all of which can have negative impacts in new habitats. Because of the danger posed by ballast water transfer around the globe, various treatments are being developed to prevent the introduction of invasive species. The International Marine Organization (IMO) has headed the regulation of ballast water issues and treatments since 2004, and currently approves 30 different treatment methods being used and developed across the world (Kim and Lee, 2009). Unfortunately, the best combination of ballast water treatment methods is still yet to be found. This is a problem that Andre May hopes to solve.
Having an interest in civil engineering and shipbuilding, May also has an interest in the ballast water issue. He felt that there is a knowledge gap as far as economic and energy efficiencies are concerned. May says that as far as what has currently been looked at, “Cost was more on consumer side, not manufacturer’s side”, and he hopes to delineate the latter half. In his proposed study, May will look at the following criteria for ballast water treatment: “the method’s cost and effectiveness, ease of installation and operation, health and environmental risks, corrosive potential (to the ballast tank’s walls), and ease of monitoring and regulation.” In particular, May will focus on three of the most auspicious treatment combinations supported by the IMO. They are filtration and water heating, electrochemical treatment and water heating, and filtration and UV radiation. By measuring the energy usage per amount of invasive species removed in laboratory conditions, May will determine the best combination for use after subsequent analysis and comparison of economic and mechanical efficiency.
Ultimately, May hopes that the proposed experiment will shed light on the most useful and practical ballast water treatment combinations. While his study will illuminate the cost-benefits of three treatment combinations, there are still many more that can be researched. However, the results of his study should give future research a strong direction, regardless of the outcome. When asked how realistic he thought implementing the best combination or combinations for ballast water treatment globally would be, he replied, “Each region has to tailor a product. It’s not something that can be mass produced easily. Different countries use the same equipment, same combinations, but don’t get the same efficiency. It depends on the environment, Arctic versus Mediterranean, etc., and geographic location for the efficiency.” Personally, his method of choice is filtration. There are few risks to consider, and there is a higher level of control in screening for invasive species. However, May also advocated for water heating as a potential treatment. He thinks that the water used to cool the engines can be recycled for use in ballast water treatment. Finally, when asked about the future of ballast water treatment and privatization versus nationalization, he supported nationalization, because in his mind it is more efficient. But those are debates for the future, and we look forward to the results of his study to lead ballast water treatment on.
Reference: Kim EC and Lee KP. 2009. Development of ballast water treatment system based on electrochemical disinfection technology. Oceans-Europe. 2009: 1-8.
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The National Research Council (2002) conducted scientific investigations of genetically engineered organisms to assess their environmental risk. After evaluating harm, hazard, and risk, William Muir of Purdue University has singled out three forms of GE modification which include inducing male-based sex ratios, releasing inducible fatality genes, and introducing non-disposable genetic loads to decrease exotic species populations. Scientists are reluctant to engage in the first two methods because they demand continuous reintroductions for effectiveness since the genes won’t spread unassisted. One disadvantageous effect associated with GE organisms, specifically non-disposable genetic loads, is the Trojan gene effect whereby subsequent development in the target species makes it more susceptible to transformation by the transgene into an even greater threat. However, this side effect may prove beneficial for the control of invasive species who up to now have only been approached via chemical, mechanical, and biological methods. Currently, implementation of selfish genes appears to hold the most promise. This alternative technology creates the spread of a ‘super-Mendelian’ gene that destroys a crucial gene function. It has a specific host (in this case, the sought-after invasive species) and employs faster eradication methods. A possible concern with this technique is the elimination of non-target species that possess similar qualities and are thus correspondingly affected.
Aquatic Sciences. DOI 10.1007/s00027-004-0721-x
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Dr. B.M.H Larson argues that the utilization of “militaristic rhetoric” by biologist in communicating about invasive species is both “problematic” and “ineffective”. He believes that such language undermines the conservative objectives of dealing with non-indigenous invasive species, and humans should have a more conservative philosophy in mitigating the effects of invasive species rather than a terminative philosophy. Yet despite the fact that militaristic metaphors have increased the gravity and awareness of the effects of invasive specie in our environment, he views this attention merely as a short term effect. Larson thinks that social issues are largely the cause for the results caused by invasive species and that militaristic language actually misleads us to implement biological solutions to deal with the invasive species. In addition, he argues that militaristic language might detract from the professionalism and objectivity of scientific publications.
Larson views two principle problems with biologists using militaristic language. First, he points out that “a war requires two opposing sides” and it’s misleading to think that they are opposing us as it was our human activities such as globalization and consumerism that transported these species to our new environment. Second, he thinks that “wars are staged on the assumption that good will triumph over evil, but will never win this war and return ecosystems to pristine states.”
Larson makes a valid point that the “we will never return the ecosystems to pristine states”. As long as humans inhabited environments, the ecosystem would no longer have been pristine. For as humans we have shaped the environment either with advantageous and disadvantageous characteristics. As the magnitude of industrialization has increased throughout the centuries, we have continuously been modifying our ecosystems more profoundly from its initial pristine state to what it current state. Humans, I believe are more aware of the affect that they are causing on their own environment. There have been ‘disputes’ within our species as how to mitigate our own effects on our environment, but we collectively as human beings view the effect of invasive species as a threat, because they are not of genus and it’s natural and instinctive that we would view them as foreigners and a threat. In addition “we will never win the war”, as invasive species cannot be eradicated, but many of the methods, humans need to manage these invasive species does require sever actions and techniques.
In my second blog post entitled “Rapid Assessment Surveys, First Step In The Fight Against Destructive Aquatic Invasive Species”, I noted that Dr. James Carlton is tracking the rising rate of destructive aquatic invasive species, for he believes that around the world, we’ve seen tremendous numbers of invasions in the last quarter of the twentieth century and these appear to be unabated as we move into the twenty-first century.” This excerpt was a commentary in response a to video documentary, which explained the effects of invasive species on our environment, how these non-invasive species were introduced to their current location, and methods being employed to ‘manage’ there effects on the environment. I viewed this document in the early stages of this course when I had a sparse knowledge of aquatic invasive species least the gravity of the effect they had on our environment. The uses of such militaristic jargon, a subtle difference from negative language, help me contextualize the situation of non-indigenous species and our surroundings. I say that there’s a subtle difference between militaristic versus negative metaphors, because militaristic jargon doesn’t always have morbid and terminative implications. I view the use of militaristic metaphors as having more grave and systematic implications, and that Dr. Larson might be over analyzing such use of these metaphors. I also do not agree with his argument that militaristic metaphor is responsible for the adverse and extreme measures humans take the ‘control’ invasive species. If he had at least considered other factors, he would have come to the realization that militaristic metaphors couldn’t be solely responsible for such human response. I would take into consideration if he had mentioned that militaristic metaphor played a minor role in such human actions.
Larson, B. M. H. 2005. The war of the roses: demilitarizing invasion biology. Frontiers in Ecology and the Environment 3: 495-500.
May, A.J. 2011. Rapid Assessment Surveys, First Step In The Fight Against Destructive Aquatic Invasive Species (Blog Post SW2), Writing 20- Aquatic Invasive Species, Duke University, Published 1/24/2011.
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The public generally perceives invasive species as undesirable pest, invading our natural environment and disrupting our thriving economy. Regardless of the pervasiveness of this general perspective, Larson argues how invasive biologist and their use of militaristic metaphors have led to misconceptions of invasive species. Larson emphasizes how utilizing militaristic metaphors as a style of writing can potentially lead to a loss of scientific creditability and ultimately result in the ineffectiveness of motivating people to take positive action.
With several invasive biologist constantly using words such as “battle”, “kill”, “eradicate”, “targets”, and “explode”, there is no doubt why the public would be misled that the act of removing invasive species is an act of war. This style of diction is intended to stimulate action amongst the public however, Larson argues that a “boomerang effect” can occur and the public will do the exact opposite. Larson exemplifies that initiating war is not the answer, for managing every species is feasibly impossible. Instead of gravitating towards war as a solution, Larson explains how we must learn to accept them within our environment, for once they have invaded they are engraved within our environment. Larson suggests alternative use of metaphors in which we could see a relationship among the invasive species. Instead of possessing the mentality of destroying and eradicating these species, Larson’s suggests that we attempt to live with them and seek methods of restoration.
After analyzing Larson’s argument on the use of militaristic metaphors, I realized that I often use militaristic metaphors when referring to invasive species, particularly in my water hyacinth paper where I allude to invasive species as “destructive”, “detrimental”, “deteriorate”, “exploded” and “harmful”. “Due to its versatile characteristics and wide range of tolerance levels, the water hyacinth has been able to dominantly flourish and disrupt several large bodies of water everywhere in the world except Europe… Within a matter of a few years the water hyacinth population had exploded into a massive population size, contributing to the loss of native plants and aquatic species, consequently resulting in the loss of biodiversity, a decline in the economy, and the formation of habitats infested with disease carrying insects. With numerous detrimental dilemmas, local biologist took action and introduced weevils in to Lake Victoria in 1996, as a method of biological control” (Muñoz 2011). My use of militaristic metaphors portrays water hyacinth plants as enemies and invaders that have “disrupt several large bodies of water” throughout the world. I continue to blame the plant for the decline in our economy and loss of biodiversity, ultimately leading to warlike actions of introducing weevils in hopes of “destroying” these plants.
Larson argues that the use of militaristic metaphors leads to the misconception of invasive species, loss of scientific credibility, and the ineffectiveness of the public to take action. However, I believe that there must be some form of militaristic terminology because we are in a sense at war with invasive species. They invade a particular environment and wreck havoc upon the regional economy, such as the presence of zebra mussels within the Great Lakes. If we don’t present these invasive species as our target, then the public might not perceive them as a threat. Despite the fact that I disagree with Larson’s view on militaristic metaphors, I do agree with him on his proposed alternatives of utilizing different metaphors capturing the relationship amongst invasive species and society and developing methods of restoration. These alternative forms of metaphors can progress the removal of invasive species, but if we don’t emphasize the negative impacts of invasive species as being detrimental to our society, then we might never be able to eradicate their presence.
Larson, B.M.H 2005. The war of the roses: demilitarizing invasion biology. Fronteirs in Ecology and the Environment 3: 495-500.
Muñoz,U. The Complexities of Eradicating the Water Hyacinth:Was it Biological Control or Mother Nature. 2010. http://sites.duke.edu/writing20_12_s2011/author/um4duke-edu/
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The context through which invasive species are described often relies on aggressive and militaristic figures of speech and expression. Larson disagrees with this particular writing style, arguing that the language alters the way that readers view the species discussed and how they react toward them. He finds that terms such as bombardment, detonation, enemy release and strategy make it seem like humans are rivals to the natural world (Larson 2005). He argues that hostile writing influences conceptions of scientific, nationalistic, and social objectivity. He even goes as far as to propose that discussing invasive species in this fashion makes certain people think of actions against exotic raiders as class-based or race-based. Larson promotes that instead we look at invasive species as some sort of disease that weaken an ecosystem’s health, like pathogens do unto the body. This metaphor emphasizes the detrimental affects of invasive species and subtly implies militarism since that is the way some diseases are combatted in the mind (Larson 2005).
In my SW3 blog post I found several examples of militaristic rhetoric. “The water hyacinth, an invasive aquatic plant indigenous to South America, continues to lay siege on Lake Victoria in Kenya.” As the paper continued I also included such expressions as termination, deployed, control agent, and war. Looking back on this post, I consider this style and wording convincing in addressing my point and I don’t think that it overemphasizes the perilousness or voracity of invasive species, specifically the water hyacinth.
While I understand Larson’s point of view and can appreciate his outlook pertaining to militaristic language and metaphor use, I do not particularly agree with him. He seems to be taking things a little too personally and his exaggerated attempts to connect society, nationalism, and politics to these militaristic metaphors fails to tickle my fancy. Invasive species generate disastrous effects on native ecosystems and economies and I find the use of warlike expressions quite fitting. They impart an appropriate amount of concern since invasive species do pose severe risks to our natural environments and are difficult to control. I am fond of his invasive species-disease analogy and would agree that this parallel is more appropriate and applicable to environmental interaction. Taking Larson’s advice and applying terms of passivity that promote “quality of life” doesn’t seem effective or wise because it downplays the major harm looming behind continued invasion. In this way, I think that the “boomerang effect” serves as an effective method of detailing the urgency with which we need to deal with exotic invaders. Persuasion of this sort bolsters more support from local community members. In sum, militaristic rhetoric serves as a practical technique for scientific writers to advocate action against invasive species by instilling feelings of environmental patriotism and acknowledging their threatening influences. It’s mode of encouragement and enlightenment seems beneficial in association with exotic invasions.
Larson, B.M.H. 2005. The war of roses: demilitarizing invasion biology. Frontiers in Ecology and the Environment 3: 495-500
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When describing invasive species, a militaristic language approach is often taken. A war is often waged on the invaders with hope of eradicating them before they overrun local ecosystems. Brendon Larson however, disagrees with this approach. He argues that if the words chosen to persuade people that invasive species require our attention are too strong, they can have the opposite effect on the reader (Larson 2005). Larson also states that when talking about invasive species, a “war” does not really exist because “good” and “evil” sides do not exist and humans have no hope of restoring ecosystems to their original state. Furthermore, he suggests that there are alternative metaphors that can describe the invasive species situation just as accurately without having to resort to militaristic terms (Larson 2005).
While inspecting my past blog posts, I realized that combative terminology is prevalent in many of them. For example, the title of one such blog post is “The Second Battle of New Orleans”, which is clearly an implication of a “war” (Wang 2011). The “second battle” is in fact not refering to a battle at all, but to the introduction of Formosian Subterranian Termites. The blog post later mentions topics for control and management, which are refered to as “eradication methods” and using chemicals to poison the termites (Wang 2011).
I do not agree with Larson’s view. Invasive species can have unforseeable impacts on both the ecology of the environment it invades as well as having disastrous consequences for the people in that region. The use of militaristic terms has always captured my attention when talking about invasive species. Strong language is necessary in invasive species ecology because it has a much better chance of getting noticed that way. The terminology may sometimes be a bit exagerated, but sometimes that is what is required for people to take invasive species seriously.
Larson, B.M.H. 2005. The war of roses: demilitarizing invasion biology. Frontiers in Ecology and the Environment 3: 495-500
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A recent study of Sea Lamprey (Petromyzon marinus) control methods was conducted by L.A. Velez-Espino and R.L. McLaughlin of the Department of Integrative Biology at the University of Guelph and T.C. Pratt of the Great Lakes Laboratory for Fisheries and Aquatic Sciences.
The invasion of Sea Lamprey into the Laurentian Great Lakes has had a profound impact on the local ecology. The lamprey has a parasitic stage during which it feeds on the blood and flesh of large fish, sometimes killing them. This along with habitat destruction and overfishing has led to declines in population and endangering of local host fish such as Lake Trout (Salvelinus namaycush).
The study employed matrix models to show that Sea Lamprey populations can continue to be controlled by decreasing use of chemical pesticides that specifically target the lamprey when it is in its parasitic stage and increasing use of alternative control methods that target the adults in their reproductive stages.
NRC Research Press Website: cjfas.nrc.ca, 2008
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The negative economic and environmental repercussions of non-native species invasion encourages citizen science assistance. Voluntary aid contributions and access to lands typically restricted from professional scientists serve as worthy advantages. However, there are many drawbacks including increased variability among data, misidentification, and oversimplified procedures yielding worthless information.
Crall et al. of the Nelson Institute for Environmental Studies at the University of Wisconsin-Madison advocates creating a worldwide database to share figures about invasive species. A survey was conducted with 249 citizen science groups regarding available resources, data collection, data management, and data assurance or control. Crall et al.’s results documented deviation between number of volunteers, available educational resources, and funding. In addition, new invasions could be missed by random sampling and small sample sizes. This justifies the reluctancy behind acknowledging data submitted by citizen scientists: their lack of scientific background prompts reliability and data quality concerns.
These surveys generated better understanding of citizen science programs and contributed to cyber resource designs, like NISS’s citisci.org, which integrate information while still protecting sensitive data.