Review Panel: Steven Blaser, Max Castillo, Cole Arora, Joshua McGrath.
Proposal (I): Zhou, Mo. 2010. “Comprehensive Prediction on Asian Carp Invasion: A Pre-Proposal.”
Proposal (I) (Zhou) sought to implement a trans-continental analysis concerning the vulnerability of rivers and waterways to invasion by Asian carp. The motivation behind the study is to assist in Asian carp invasion prediction, which would in turn more readily allow for prevention and detection programs. Water systems surveys and data collection will not be conducted in situ, but rather, current literature, local information and the opinions and findings of current experts in the field will be compiled and reviewed by the author and collaborators. The overarching, apparent goal is to form a comprehensive, preliminary risk assessment that can be updated as necessary as more information is gleaned.
Proposal (II): Starnes, Abby. 2010. “Invasive Bullfrog Transmission of Chytrid Fungus to Red-Legged Frogs.”
Proposal (II) (Starnes) focuses on the important role that chytrid fungus plays in the invasion mechanism of bullfrogs (Rana catesbeiana). The author makes the hypothesis that, because transmission of the fungus from bullfrogs to other anuran species has been well-documented, the possibility for that event to occur between bullfrogs and a specific native species – red-legged frogs (Rana aurora) is a logical research question. Testing this hypothesis involves exposure of healthy red-legged frogs to bullfrogs of varying condition (e.g. infected, not infected) and observing the transmittance of the pathogen. The hope of the study is to illuminate a potential cause of damage that bullfrogs initiate as a result of invasion, and to then concentrate on alleviating that damage source, rather than on widespread eradication of the species.
Proposal (III): Tully, Daniel. 2010. “The Effects of the Poison Rotenone on Rivers when used to Eradicate an Invasive Species.”
Proposal (III) (Tully) explores the possibility of applying poison – specifically, rotenone – to rivers as a means to eradicate invasive northern snakehead (Channa argus). The author references that a major disincentive from using the poison previously had been the fact that it incurs mortality both in the invasive species as well as the native species. He introduces the idea of combining the extremely effective rotenone with a decomposition catalyst, potassium permanganate, in order to reduce the long-term effects of lingering rotenone in river systems. The proposed study involves extensive pre-test initiatives, including such things as removal of a control group of several thousand fish via electrofishing to be reintroduced later on, a week-long application of rotenone, followed by a five-year-long observation period on the effects of rotenone application (with the potassium permanganate compound) in the long term.
Proposal (IV): Arcia-Ramos, Jania. 2010. “Public Awareness of Mute Swans is Key to Legislation Support.”
Proposal (IV) (Arcia-Ramos) revolves around different approaches that could be taken to recruit public support for control of invasive species, specifically the mute swan (Cygnus olor). The author cites the lack of public support for invasion control as a main reason why roadblocks to stricter control exist in the political arena. In fact, the author claims that a public that is generally opposed to eradication of an invasive species can actually assist the further establishment of that species (through misinformed advocacy). Thus, a major component of the study is to test the effectiveness of different approaches for providing invasive species education to the general public. Pre- and post-test surveys will establish baseline comparison with results, and individual tests involve pamphlet distribution and publishing articles in media. Treatments differ in terms of the frequency of distribution or publication.
The panel recommends funding to be directed towards the proposal of Starnes. The impetus behind her planned experiment is well-conceived; the methodology of the planned tests (the experimental design) is logical, comprehensive, and testable; and the study in general is not only novel but applicable to anuran-bullfrog interactions in general. Thorough background research was conducted concerning the pathogen, and we feel confident that her study will generate statistically significant results. Moreover she also demonstrates proper perspective, in that identification of pathogen transmittance could help concentrate control efforts – the pathogen could serve as a focal point to unify control approaches. Small issues found with the proposal involve the substitution of pertinent information (specifically, how test bullfrogs will be infected with the pathogen) with an unelaborated-upon reference to the work of another scientist, though the missing information does not detract from the general goal of the study.
We also, as a panel, recommend the revision and re-submission of the proposal of Zhou. We agree that a unification of data concerning the proliferation capacity of Asian carp is needed, and legislative efforts to combat the species’ expansion would be facilitated, the proposal – involving only a collection of current primary literature – would still be bounded to the realm of scientific literature, and be of use only to other scientists and resource managers. That is, in order to increase political awareness of Asian carp invasion, perhaps what would be of greater general utility is a translation of the current scientific knowledge on the carp species in terms that policy-makers and legislators can understand. Presentation of the findings to congress and in hearings at the state and local levels would have a much larger reach, than would publication of a literary review.
The major fault holding back our decision to fund the proposal of Arcia-Ramos – an otherwise exemplary effort to quantify the invasive species information processing of the public – was the high sensitivity of her study to bias as a result of subjective sampling measures. Because the author – highly motivated to persuade the public in favor of invasive species control – has a personal stake in the experiment, the very language used to write the pre- and post-experiment surveys could slant any findings and render the baseline data collected from them questionable. A way to correct for this could be to hire a third party to actually draft the surveys; in this way objectivity might be attained. But even working under the assumption that the exact reflection of public opinion is attained through the surveys, another problem exists. The author explicitly states that the test mediums are being directed toward an audience that “feel more strongly about the issue” compared to others lacking exposure to mute swans. Thus, only those citizens who actually want to observe the mute swans (because of their beauty, say) would be present at the sites where the pamphlets supporting their eradication are being distributed; in other words, the pamphlets advocating for removal of mute swans are given to those who are the most opposed to the information presented to them. Lastly, publication of stories in media, while it would certainly have an encompassing effect due to the medium’s omnipresence, is not feasible. Specifically, local public media actually have to want to publish or broadcast the work. There is no incentive for them to put forth ideas that go against the general grain of public consensus. As a result, the only alternative would be publication in the form of scientific papers, which the general public do not normally read. Revision of distribution mechanisms of the information could be a potential solution to the problem.
Similarly, Tully’s proposal is well-presented and well-conceived, but there exist inherent discrepancies that cause us to favor the proposal of Starnes. Beginning with an anecdote, the overage of the current status on rotenone and control of invasive northern snakehead was quite strong. However, the novel aspect of the study – combining rotenone with potassium permanganate – was presented without any citation, indicating that the idea of the compound’s efficacy came from the knowledge and past experience of the author; its use as a catalyst for the decomposition of rotenone must be firmly established in order to assuage our fears that the permanganate will do its job. Second, the logistical ramifications of the five-year study are astronomical, and thus we fear for the experiment’s testability. Even using a barge equipped with electrofishing equipment, the removal of several thousand fish is not an inexpensive undertaking – much less the daily electrofishing during the sampling time and the twice-daily water testing throughout the entire experiment. Because no particular reason for the five-year study is given, we recommend shortening the duration of the study. Thirdly, and most contributory to our decision to decline grant funding, is a flaw in the experimental design. As written, the author plans to apply rotenone poison for a week; subsequently, if a water test indicates lingering rotenone, the potassium permanganate will then be added to break it down completely. This came across as an afterthought – if the amount of time that the northern snakehead were exposed to the rotenone before the permanganate application was sufficient to kill them, it would also be sufficient to kill all other natives (unless snakehead are affected to a greater extent, which was not specified). In this way, the permanganate serves no purpose, and actually does not play a role in the experiment in the short-term. Only in long-term observation of how the fish that were removed fare in the ecosystem can the effects of potassium permanganate actually be used (but by then it is too late for the natives that were not removed). The rub of the problem is that, if rotenone and permanganate were to be simultaneously added, the latter would decrease the effectiveness of the former, and in all likelihood 100 % eradication would not be achieved. Revision of experimental design is necessary before approval can be given.
GR Smith and his team used groups of eggs of both the American bullfrog and the American toad to observe the tendencies of the tadpoles of each species. The primary goal of the study was to determine if certain predator cues made the tadpoles react differently. The hypothesized cues were group size, age, size, and predator identity. The program MANOVA was used to calculate the effect that each cue had on the tadpoles, and the scientists were able to determine that the tadpole varied its behavior, as expected, when confronted with different predatory cues.
I could expand on this study to determine which predators the bullfrog tadpoles react to the least and the native frogs in a certain area respond to most. Knowing which predators the bullfrog is more susceptible to while other species are less susceptible could help lower bullfrog population with the use of properly researched biocontrol.
Smith, GR, & Awan, AR. (2009). The roles of predator identity and group size in the ntipredator responses of american toad (bufo americanus) and bullfrog (rana catesbeiana) tadpoles . Behariour, 146(2), 225-243.
Starting in 1959, the American Bullfrog has been introdouced into most provinces in China, and because of its size and predatory nature, has been able to thrive off consuming the native species. The bullfrog has been known to eat a number of the native anurans, but to what extent has been hard to determine for scientists. Yanping Wang and his team from The Society for the Study of Amphibians and Reptiles, decided to try and determine which prey the bullfrogs preferred to determine the overall effect the bullfrog has. First, they tested which bullfrogs, larger or smaller and male or female, consumed most on a daily basis. Then they determined which of the four main sources of food the bullfrogs preferred and which size. The results of the experiment showed that the though the bullfrogs preferred the smaller species such as the Rana limnocharis but only because of the species generally smaller size compared to the other prey.
Journal of Herpetology. Volume 41, p. 514-520.(2007)
Human construction disturbs the natural habitats of red-legged frogs in Oklahoma, according to Joseph Kiesecher of the Biology Department at Pennsylvania State University. Human interference changes open, shallow ponds with scattered food resources into small permanent ponds with clumped food resources. This hinders red-legged frog growth while increasing invasive bullfrog population growth.
Bullfrogs have an earlier breeding season than red-legged frogs, so their larvae are larger and more developed than red-legged frog larvae. The bigger bullfrog tadpoles can therefore consume red-legged frog larvae. The difference in size between the frogs also triggers a passive interference mechanism in the red-legged frog, in which red-legged frog tadpoles avoid the larger bullfrog tadpoles when possible.
This is a problem in clumped resource ponds because red-legged frogs often can’t feed without bullfrog interference. In this situation red-legged frogs go through metamorphosis slowly, develop into smaller adults, and have a lower survival rate than those that breed in scattered food ponds or without bullfrog presence.
Ecology, Vol. 82 (pp. 1964-1970)