Aquatic Invasive Species

According to Dr. David M. Lodge’s lecture about science on the front lines of invasive species management and policy on March 16, 2009, at Duke University, the United States’ current system for invasive species control is not adequate and needs reform. One of the principles of Lodge’s argument involves taking a new perspective and looking at invasion potentials in probabilistic terms. Lodge claims that the invasion process can be broken up into successive steps that include, in order, the introduction of the species into a pathway, the transport and release a living specimen, the establishment of the invading population, that population’s spread, and finally concluding with ecological, human health, and economic impacts. Lodge’s new suggestion to controlling invasive species involves attention to and analysis of each individual pathway individually. He claims that the probability of a successful invasion is the combination of the probabilities of each step in the invasion process. Thus, in order to more effectively target invading species, the focus should be on the step with the highest probability, followed by combating the steps with the next highest probabilities. This way, only the most beneficial approaches will be focused on first. According to Lodge, recent scientific advances allow accuracy in specific species risk assessment up to eighty and ninety percent, so the future for this method of controlling invasive species is very promising.

To this point, the United States has had some success in invasion control using geographic modeling and environmental matching techniques. Lodge and colleagues have performed a great deal of research analyzing the temperature and salinity conditions of ports throughout the world. The results of their studies have been effective in determining the risk of invasion of aquatic species, including the zebra mussel, at various locations throughout the U.S. However, this is one of the few bright spots in U.S. control of invasive species because there are many more problems than effective solutions. First of all, there are few importations restrictions in the United States, and because of the rapid growth of globalization, there is a huge issue over control of shipping. The Lacey Act has failed to accomplish its main purpose, as it is ineffective at preventing the importation of invasive species. The few restrictions on importations that do exist are primarily motivated by the desire to protect humans (primarily from disease); also, animals are easily transported because they are considered innocent on charges of invasion ability unless already proven guilty. Furthermore, Lodge notes that policy to control both national and international trade is a long time coming. The better solutions to these outlined problems are early detection and rapid response. One technique that has been proposed by Lodge to fight the high Asian carp density in the U.S., which might be higher than its native population density, is the use of eDNA sampling. This would be an example of early detection because if the presence of an invasive species can be determined before its full-fledged invasion, the species can be more easily controlled. Rapid response is also key to eliminate the threat before it becomes too widespread.

In his article, Brendon Larson discusses the use of “militaristic” rhetoric to describe the issue of invasive species. Larson argues that the use of metaphor misleads the public, and even scientists, into a false perception of the invasive species issue and how to effectively deal with it.

For example, a recent article in Time – entitled “Asian Carp in the Great Lakes? This Means War!” – proves Larson’s point. In addition to the title, language such as “infiltrating a new home,” or “eradicate them after the fact” (Walsh, 2010) compares the idea of invasive species to an enemy that must be defeated in war. I agree with Larson that this kind of rhetoric leads us to think that a “brute force” approach is the only way to deal with the invasive species problem – which is problematic because this kind of approach is usually the least cost-effective and successful. However, I think that there is some use to this kind of rhetoric. The metaphor is necessary for the public to understand the issue of invasive species. Especially in a popular magazine such as Time, overly scientific language would not be of any use to the general reader.

Larson, 2005. The war of the roses: demilitarizing invasion biology. Frontiers in Ecology and the Environment.

Walsh, 2010. “Asian Carp in the Great Lakes? This Means War!”. Time Magazine. http://www.time.com/time/health/article/0,8599,1962108,00.html

In his paper “The war of the roses:  demilitarizing invasion biology,” Larson asserts that, by using militaristic language when discussing the problem of invasive species, we limit our perspective on these creature to one that advocates aggression and urgency and overlooks that some situations may benefit from caution and sympathy.  Larson also asserts that, if invasion biologists are too quick to call this sort of negative attention to a foreign species that does not turn out to be a large threat, organizations that may otherwise be supportive of the goals of these biologists may stop taking them seriously.

Larsen is certainly correct in his assertion that militaristic is quite prevalent in invasion biology.  In the Science magazine article “Biologists Rush to Protect Great Lakes from Onslaught of Carp” (2010), militaristic language is used in the very first sentence.  Erik Stokstad states, “With Asian carp poised to invade Lake Michigan, wildlife managers…are scrambling to shore up defenses.”  Though the dangers of Asian carp invasion are serious and may have far-reaching effects, whether there is need to compare invasion prevention methods to preparing for war is debatable.

Though Larsen makes a good point that militaristic language is overly prevalent in invasion biology literature, I do not believe that militaristic language should be completely absent when presenting information about such species.  Especially in press releases, such as the article from which the quote above is from, militaristic language may be useful in helping the average American–who most likely does not particularly care about the environment–realize the magnitude of the issue.  However, I do agree that metaphoric militaristic language is not appropriate in more formal literature.  As long as  militaristic is kept in its place, it may accelerate efforts to keep invasive species in their respective places, as well.

Larson, Brendon MH.  2005.  “The war of the roses:  demilitarizing invasion biology.”  Frontiers in Ecology and the Environment 9: 495-500.

Stokstad, Erik.  “Biologists Rush to Protect Great lakes from Onslaught of Carp.”  Science.  19 February 2010.

Larson, in the war of the roses: demilitarizing invasion biology, argues that the prevalent use of militaristic language in scientific articles and other media to describe invasive species is counterproductive. Not only do militaristic language over-exaggerates the problem of invasive species, but also promotes drastic measures to eradicate the problem that are completely unnecessary and wasteful. More often than not, exotic species become integrated into the ecosystem that it is introduced into. Consequently, its complete eradication will only harm the indigenous species that have come to rely on it for various reasons. Instead viewing foreign species are invaders, Larson argues that we should see them rather as new visitors, and accept them under a symbiotic relationship.

Quote: “With Asian carp poised to invade Lake Michigan, wildlife managers are urgently trying to figure out how many of the voracious 1.5-meter-long fish have already slipped past electric fish barriers in a waterway near Chicago and they are scrambling to shore up defenses.” (Stokstad 2010)

Though there are definite faults to Larson’s argument, I agreed overall with the author’s argument. Such as the above passage from Science Magazine concerning the “onslaught” of Asian carp, there are too much anxiety and urgency in scientific literature to correct something that does not require such drastic methods. The usage of militaristic promotes an unnecessary false sense of urgency that will only become counterproductive. It is not only infeasible, but also potentially detrimental to the ecosystem, to eliminate invasive species that have integrated themselves into their introduced habitat. It is worth the risk and resources to put poison in the water just deter Asian carps from becoming introduced into Lake Michigan? Do we really need $2.5 million dollars just to eliminate Asian carp? Aren’t there other better venues the money could be used for? However, I must acknowledge that militaristic words are used throughout the vernacular. And that as a result, its use in scientific literature is only reflective of how we speak on a day-to-day basis. At the same time, just as Larson argues, though using militaristic language in scientific literature is nothing to be alarmed about, it is the frequency at which it is used to describe invasive species that we should be concerned with. Too much usage of militaristic language jades the reader against future crises that might be greater than a carp trying to get into a lake. Like the boy who cried wolf, what will we do then?

Larson, BMH. 2005. The war of the roses: demilitarizing invasion biology. Frontiers in Ecology and the Environment 3: 495-500.

Stokstad, E. (2010). Biologists Rush to Protect Great Lakes From Onslaught of Carp. Science. 327(932)

As I wrote on January 14, concerns have been growing over the possibility of Asian carp entering the Great Lakes. Scientists at the University of Notre Dame have been maintaining an environmental DNA monitoring program in the waterways around Chicago. In the Fall Asian carp DNA was found in the Cal-Sag channel (see map at the end of this article), and now, according to this Chicago Tribune article, Asian carp DNA has been found in Lake Michigan. As stated in the article, the DNA identification does not necessarily indicate the definite occurrence of a live specimen; the DNA could have come from the sewer system or transport of carp feces. However, the scientist in charge of the DNA analysis spoke at the Chicago meeting I attended last week, and he stated that it was very unlikely that the DNA came from these other pathways.

Welcome! The primary purpose of this blog is for Duke Writing 20 students enrolled in “The Billion Dollar Problem of Aquatic Invasive Species” to share their research findings, opinions, and questions with an audience beyond our classroom. Our Writing 20 course will work with many forms and genres of reading and writing, and this blog will be just one of them! But I thought I’d get the ball rolling on this blog by posting about my trip to Chicago yesterday.

I attended (and gave a talk at) the Aquatic Nuisance Species Dispersal Barrier Panel Meeting. The agenda for the meeting can be found here. This group meets about 2-3 times a year to discuss the electric fish barrier in the Chicago Sanitary and Ship Canal. The main purpose of this barrier is to prevent invasive Asian carp (bighead and silver carps) from entering Lake Michigan. Today’s meeting was especially important for many reasons, including:

1. Asian carp DNA was found ABOVE the barrier this past Fall
2. A multi-million dollar fish poisoning effort – one of the largest ever – near the barrier yielded one bighead carp (among thousands and thousands of dead fish).
3. Michigan is now suing Illinois to close the canal.
4. Obama is backing Illinois’ desire to NOT close the canal.
5. Everyone’s freaking out or arguing about whether we should be freaking out.

You can read more about the barrier issues here and Asian carp and the Great Lakes here. I had been invited to give a talk on using Asian carp bioenergetic models to predict the ability of this invader to become established in the Great Lakes. Some question whether the voracious, plankton-eating carp would be food-limited in the low productivity Great Lakes. The short answer from the models is: probably, sometimes, in some places, but it depends. That’s science for you! I think my talk was well-received, so I guess it was worth the effort to fly from RDU to Chicago and back in one day!