An Ecological Risk Assessment on the Use of 3-Trifluoromethyl- 4-nitrophenol (TFM) for the Control of Sea Lamprey in the Lake Champlain Basin

Transcription

1 1 An Ecological Risk Assessment on the Use of 3-Trifluoromethyl- 4-nitrophenol (TFM) for the Control of Sea Lamprey in the Lake Champlain Basin By Chelsea Mandigo, Ryan Patnaude, Audrey Reid, Elias Rosenblatt and Emily West Executive summary Sea lamprey (Petromyzon marinus) is a parasitic fish whose primary hosts are sport fish such as lake trout (Salvelinus namaycush) and landlocked Atlantic salmon (Salmo salar). Due to an increase in sea lamprey population and elevated wound rates management of the species has increased. Control of populations has been primarily done through the use of lampricide, more specifically 3-Trifluoromethyl-4-nitrophenol, (also known as TFM). The scientific community knows relatively little regarding the effects of this chemical. The growing social awareness of pesticide use has made chemical controls such as TFM application a controversial issue. Historically, sea lamprey were thought to have been an exotic invasive species. Recent evidence suggests that sea lamprey are likely native to Lake Champlain. The new evidence regarding the origin of the species may play a role in how stakeholders wish to proceed with the control of the species. The goal of this assessment is to investigate the effectiveness of the lampricide, 3-Trifluoromethyl-4-nitrophenol, (TFM) and whether or not it is an appropriate method for controlling sea lamprey populations in Lake Champlain. To achieve this goal we will examine the following topics in relation to the Lake Champlain Basin: the issue of sea lamprey being native to the lake, the effect of sea lamprey on sport-fish, the chemical effects of TFM on sea lamprey and its corresponding aquatic environments as well as the impact of TFM on non-target species. We will conclude with the cost benefit ratio of using TFM as a control mechanism for sea lamprey in Lake Champlain along with our recommendations of how the community should proceed. From our assessment we do not believe there is any compelling evidence to suggest that TFM is a significant harm to any species or ecosystem if applied as directed by experts. We recommend that continued application and treatment of the lampricide TFM should be used along with the monitoring of impacts on non-target species. Purpose Statement Our team will investigate the application of the lampricide 3-Trifluoromethyl-4- nitrophenol, (TFM) to find out if it is an effective and appropriate technique for controlling sea lamprey within Lake Champlain.

2 2 Objectives To reach the above-stated goal, we will achieve the following objectives: 1. Determine the chemical effects of TFM on sea lamprey and its corresponding aquatic environments 2. Investigate the nativity of sea lamprey, and how a potential native status would affect public opinion of the sea lamprey control program 3. Evaluate the effect of sea lamprey on sport-fish species in Lake Champlain 4. Understand the effects of TFM on non-target species 5. Analyze the cost-benefit ratio of using TFM in the Lake Champlain Basin Background Following efforts in the 1950's and 60's to re-establish a viable population of the sport fisheries extirpated during the 19 th century, sea lamprey were noticed to have a major impact on restoration efforts (USFWS 2001). In order to minimize the losses on lake trout, landlocked Atlantic salmon, other stocked salmonids, and walleye, Vermont Department of Fish and Wildlife (VTDFW) and New York Department of Environmental Conservation (NYDEC) began an eight-year experimental sea lamprey control program using 3-trifluoromethyl-4-nitrophenol (TFM) (USFWS 2001). The program has been expanded since the conclusion of that eight-year period, and now lampricide is applied to streams every five years. Though the chemical has been used since the 1950's, the mechanism by which it targets sea lamprey and its effectiveness is still unknown (Zerrenner and Marsden 2006). Studies have shown lampricide does effectively kill lamprey in their larval stages, and has been used as a method for controlling lamprey populations (USFWS 2001). Sea lamprey spend a majority of their lives as larval transformers (from 3-17 years) in streams, while only months of their lives as parasitic adults (see Figure 1) (NY DEC).

3 3 Figure 1. Sea Lamprey Life Cycle (NY DEC) Currently, long-term effects of lampricide application are not known as is the case with many new chemicals. In addition to the unknown effects of current lampricide treatment, other uncertainties may affect the extent and continuation of the sea lamprey control program. The debate of whether sea lamprey are native or not is a heated one, and if the consensus shifted to one supporting sea lamprey as a native species, management priorities may shift as well. The economic viability of a widespread control program in the current economic climate may also change management priorities. As government funding is being cut, increased application of TFM may not be an economically viable option. Approach Electronic search engines such as Web of Science ( Google, and Google Scholar were used to find peerreviewed journal articles. Search terms TFM, use, application, effects, effectiveness and properties, cost-benefit analysis, sea lamprey effect on sport fish in Lake Champlain, sea lamprey and sport fish, sea lamprey, Lake Champlain, and native were used. Most of these searches directed us to journals such as the Journal of Great Lakes Research, Transactions of the American Fisheries Society and Molecular Ecology. Scientifically acceptable websites like the New York State Department of Environmental Conservation, USGS Great Lakes Science Center, Lake Champlain Basin Program etc. were also used. Ellen Marsden served as a personal resource. As

4 4 a guest editor and contributor for the Journal of Great Lakes Researcher as well as being affiliated with the Lake Champlain Sea Lamprey control initiative, she proved to be a key resource in directing areas of research in this ERA. Findings Sea Lamprey and Their Origin in Lake Champlain Parasitic sea lamprey have caused considerable damage to Lake Champlain's sport fisheries, resulting in lower tolerance of the species by relevant stakeholders. This has led to subsequent experimental use of TFM by federal and state authorities to suppress sea lamprey populations in the Lake Champlain basin (Marsden et al. 2003, Smyth et al. 2007). Smyth et al. (2007) reported that their survey of public opinion identified one or more lamprey wounds on a fish to be unacceptable, and concluded that to meet the public's interest, regulation of sea lamprey population would need to be increased. In addition, Marsden et al. (2003) estimated an economic benefit to continued TFM treatment in the Lake Champlain basin, primarily due to the decrease lampreyinduced mortality of sport fish raised with taxpayer's money and increasing recreation on the lake. It is no surprise that the continued treatments of TFM and the general suppression of sea lamprey in Lake Champlain have gained support through scientific studies and stakeholders opinion. However, ethical issues may come into play if the sea lamprey are deemed to be native to the lake. For many years, government agencies and the scientific community identified sea lamprey as a non-native marine species that invaded through man-made canals and locks into Lake Champlain (USFWS 2001). The hypothesized invasion of Lake Champlain occurred through either the northern Chambly Canal from the Richelieu River and the St. Lawrence River, or through the southern Champlain canal from the Hudson River (Waldman et al. 2006). However, the Richelieu River did connect the St. Lawrence River to Lake Champlain prior to any man-made canal, so the potential for natural dispersion is quite possible. In order to identify the origin and invasion path (if the species did invade) of the Lake Champlain population, genetic studies (the methods unavailable until recent) were conducted, comparing Lake Champlain's population to marine and freshwater populations. Using mitochondrial DNA (DNA passed maternally) sequencing, Waldman et al. (2006) found that the Lake Champlain population was genetically distinct from populations from the Atlantic and Lakes Ontario and Superior, but the study did not provide evidence that Lake Champlain sea lamprey were native. Additionally, ndna markers were analyzed and showed shared haplotypes (a combination of alleles in close proximity on the same chromatid) between Atlantic and Champlain populations, but unique haplotypes differed between the two populations, suggesting that enough time passed for the rare marine haplotypes to be lost and for unique Champlain haplotypes to develop (Waldman et al. 2006). Using microsatellite nuclear DNA, Bryan et al. (2005) reached a similar conclusion, and though there are viable reports of canals facilitating sea lamprey invasion to the some of the Great Lakes, Lakes Ontario and Champlain were populated naturally. Bryan et al. (2005) concluded that the difference in genotypes between Atlantic and Champlain populations was far too great to have split only in the 19 th century, when the north and south canals were constructed. The absence of sea lamprey from fishery inventory prior to the first confirmed identification in 1930 is thought to be due to a lower

5 5 population in the lake with less of an impact on the commercial and sport fisheries (Brian et al. 2005, Waldman et al. 2006, USFWS 2001). The sudden over-abundance of sea lamprey in Lake Champlain, though characteristic of an invasive species, is hypothesized to have been due to anthropomorphic alterations of predator population, water quality, and prey availability (Brian et al. 2005, Marsden et al. 2003, Waldman et al. 2006). Though genetic markers support the species as native, many parties are still convinced that the availability of entry points to the lake, combined with the lack of recorded catches prior to the species abundance points to the species being invasive. However, based on the two studies discussed above, there is compelling evidence to support the hypothesis that the species is native, not invasive. This support does not change the fact that a large number of stakeholders find this species a nuisance, and as it affects valuable resources in the lake, sea lamprey populations will continue to be suppressed. If public and managerial opinions do shift with this notion, managers and public officials may wish to integrate this change into long-term treatment plans. Sea lamprey affect on sport fishery Adult sea lampreys are parasitic. They attach to the host fish and drain its bodily fluids, often killing the fish. Fish that do survive a sea lamprey attack have to spend more energy healing their wound than producing eggs and mating (NY DEC 2010). Sea lamprey preferred hosts are landlocked Atlantic salmon (Salmo salar) and lake trout (Salvelinus namaycush), however they also feed on lake whitefish (Coregonus clupeaformis), walleye (Stizostedion vitreum), northern pike (Esox lucius), burbot (Lota lota) and lake sturgeon (Acipenser fulvescens) (NY DEC 2010). Many of the fish species sea lamprey feed on are native to Lake Champlain and are important sport fish that are highly prized and sought after by anglers. The current fishery in Lake Champlain is based on angling of sport fish with the most popular species being walleye, yellow perch, basses, and pikes (Fisheries Technical Committee 2009). In addition, lake trout, landlocked Atlantic salmon and brown trout are also popular sporting species that are stocked in the lake (Fisheries Technical Committee 2009). Sport fishing on Lake Champlain creates recreational as well as economical benefits for the area. Holding summer fishing tournaments for various species like bass or trout bring in considerable revenue for the Lake Champlain area. However, sport fish populations have been negatively impacted by the increase in population of sea lamprey. In general, studies in the Great Lakes show that fish wounded by sea lamprey have a 40-60% mortality rate and that the estimated number of pounds of fish killed by each sea lamprey can vary from 15 to 40 pounds (USGS: Great Lakes Science Center 2008). In Lake Champlain, the increase in sea lamprey population has been one of the limiting factors affecting the success of the stocking efforts to restore the once native species, lake trout and landlocked Atlantic salmon due to significant mortality rates (NY DEC 2010). Prior to sea lamprey control efforts in Lake Champlain wounding data and catch rates indicated sea lamprey were having a serious impact on lake trout fishery. An eight-year study conducted by the U.S. Fish and Wildlife, examined pre and post experimental control of sea lamprey by comparing data from the main lake portion of Lake Champlain, Lake Ontario and Cayuga Lake. In particular, gill net catch rates and wounding data from the mid 1980 s (prior treatment) were examined for these sites. Gill net catch rates indicated that there were 6-13 lake trout/1000 feet of net as compared to Lake Ontario which had lake trout/1000 feet of net and Cayuga Lake lake

6 6 trout/ 1000 feet of net (USFW 2001). This study noted that 6-13 lake trout/1000 feet of net was a low catch rate for Lake Champlain considering the fact that the stocking rate of lake trout in Lake Champlain and Cayuga Lake were similar (1.6 yearling lake trout/acre for Lake Champlain, 1.7 yearling lake trout/acre for Cayuga Lake) and three times greater than Lake Ontario (0.5 yearling lake trout/acre) (USFW 2001). In addition, the wounding data indicated that total incident of attack (including wounds and scars) for all size trout prior to sea lamprey control ( ) averaged 85%, while wounding rate (the average number of wounds per 100 fish) was about 50%. More specifically lake trout inches had a wounding rate of 20% while larger lake trout inches had a wounding rate of 50% (USFW 2001). Due to the evidence that sea lamprey were significantly reducing the lake trout population as well as salmon of Lake Champlain, an eight year experimental control program was initiated in 1990 to examine the effectiveness of lampricide treatments at reducing sea lamprey populations (USFW 2001). As part of the study a pre and post treatment creel survey was conducted indicating that there was an estimated 76% increase in lake trout caught in Lake Champlain. After evaluating the success of the eight-year experimental program, a long-term control program was developed and implemented in This program involved treating thirteen tributaries with the lampricide TFM and five tributary deltas with Bayer 73 (Lake Champlain Basin Program 2008a). The goal of this program was to reduce the wounding rate by sea lamprey to 25 wounds per 100 lake trout and 15 wounds per 100 Atlantic salmon. Wounding rates have fluctuated over time (Figure 2) however all are greatly exceeding the target goals (Lake Champlain Basin Program 2008b). Despite treatment, the highest sea lamprey wounding rate was observed in 2006 with 100 wounds per 100 lake trout. This number has since declined to 46 wounds per 100 lake trout in 2007 and 31 wounds per 100 lake trout in 2008 (Fisheries Technical Committee 2009).

7 7 Figure 2: The number of Atlantic salmon and lake trout in Lake Champlain with wounds (both scar and actual) from sea lamprey. In addition, this figure indicates the target goal of wounding rates established by the long-term control program of sea lamprey populations. Source: Lake Champlain Basin Program; State of the Lake Report (2008) Historical Use of TFM TFM and its sister lampricide Bayluscide (5, 2 -dichloro-4 -nitrosalicylanilide or niclosamide) were first chosen as the most desirable lampricides by the Hammond Bay Biological Station (HBBS) in Millersberg, Michigan during the 1950 s. The two chemicals were chosen from 6,000 possible lampricides based on static laboratory tests. These tests were used to infer the concentration necessary to maximize lamprey kills. HBBS first determined the acceptable toxicity to be equal to that which would kill 99.9% of lamprey larvae and no more than 25% of test game fish. It became apparent that water chemistry and dilution of the TFM determined the effectiveness of the chemical (Johnson et al. 2003). Marsden (2010) notes that application in the 1950 s was catalyzed by the observation of limited non-target mortality/negative effects. Following the initial static lab tests, a majority of application levels have been influenced by observations made during treatments (Johnson et al. 2003). This limited laboratory experimentation is one of the factors that concern community stakeholders.

8 8 Application of TFM TFM is applied to streams in a liquid solution that is released from a perforated hose set across the stream or river being treated. The TFM exposure is set to one 12- hour application. Locations of treatment are chosen based on spawning areas that contain large concentrations of larval sea lamprey. Block application references the barrier or physical location from which the application originates. Generally the application is initiated at a physical barrier such as a dam or bridge. TFM boosts are locations within the treatment area determined to require an extra injection of TFM because they are so far down stream that the original TFM concentration has become too dilute (Marsden, 2010) Chemical Composition and Ecological Persistence TFM is a relatively stable compound with an aromatic ring structure (Figure 3). A melting point of C and boiling point of C also indicates chemical stability in terms of volatilization and suggests that effects from inhalation are not a concern (Hubert, 2003). Figure 3. TFM has a stable aromatic ring structure. Studies have shown that TFM is not an environmentally persistent compound (Table 1). Adsorption by sediment has been shown to be variable depending on the sediment source. Kempe showed that a greater percentage of organic matter in sediment increased the rate of loss of TFM (as cited by Hubert, 2003). In a sediment system of 11.7% organic matter and a TFM concentration of 25ug/mL, the chemical was undetectable in the water table by day 24 of the experiment. A corresponding sediment system with only 5.2% organic matter experienced an initial drop in TFM concentration by day 18 and stabilized at a concentration of 1-2 ug/ml for the remaining 30 days of the experiment. Hubert (2003) had similar findings when studying 3 Michigan Rivers. The investigation found that when treated with TFM (concentrations no greater than 8,000 ng/ml) the chemical was undetectable in the water column and sediment within 72 hours. Carey and Fox (1981) were able to determine the level of photodegredation of TFM in UV light. The purpose of the study was to show the susceptibility of the chemical to UV breakdown. The half-life of TFM in the stream conditions, receiving natural sunlight was shown to be between 3 and 5 days. Photodegredation in the treated streams was confirmed by the presence of the same decomposed stable products found in the lab study.

9 9 Studies have been conducted to determine the biological cycling of TFM through plant and animal species. Kawatski and Bittner (1975) noted that the most significant factors affecting TFM uptake were concentration and ph. The photobreakdown of TFM was also shown to increase with ph. Fathulla (2001) found that at ph 9 the half-life of TFM was 3-4 hours. In ph 7 the half-life was 4 hours, and at ph 5 the half-life was 11 hours. These results indicate that as ph decreases TFM becomes more persistent. Similarly, McDonald and Kolar found that the toxicity of TFM is approximately 5 times greater at ph 7 than ph 8 when measured at LC50. As the acidity increased the amount of TFM required to generate mortality of 50% of the population increased (Figure 4). Marsden (2010) confirmed that ph plays a key role in application, because of the daily variability of stream ph. Specifically, she recommends that the 12-hour period of application be done in a window that allows for the least ph variability. Alkalinity also appears to play a role in the TFM toxicity separate from ph. As alkalinity increases the toxicity of TFM has been shown to decrease. The relationship between alkalinity and toxicity has not been studied outside of observations made during application (McDonald et al., 2007). The uncertainty associated with alkalinity suggests that further studies should be conducted to obtain proper protocol when dealing with varying levels. Erring on the side of caution MacDonald et al. recommended TFM application be done during times when water chemistry is most stable; this will control the toxicity and persistence of the chemical (2007). ph Figure 4. The effect of TFM is shown to increase as ph decreases. The positive relationship shows that at higher ph a higher concentration is required to produce equitable mortality (from Bills et al., as cited by Hubert, 2003). TFM has been shown to have limited persistence in animal species as well as plant species when applied in the suggested concentrations (Table 1). Both plants and animals take up TFM during treatment but when exposed to TFM-free water are able to eliminate the chemical (Hubert, 2003). Schultz et al. (1979) confirmed this by placing largemouth bass in TFM free water after a 12-hour exposure. These results followed the findings of Maki and Johnson (1977), which showed that the rate of TFM loss was dependent on water current and substrate. After 72 hours the study organisms

10 10 contained no residual TFM. Similar results were found in rainbow trout, blue gills and channel catfish, further suggesting that TFM does not persist in aquatic species. Table 1. Concentration of TFM in fish, vascular plants, and sediment found East Au Gres River, Michigan before, during and after a study conducted by Gilderhus (as cited by Hubert, 2003)with TFM concentrations of 11 mg/l. Within 96 hours none of the study variables contained residual TFM. Bothwell et al. (1973) studied the biotic breakdown of TFM in a sediment substrate and showed that the chemical was reduced to 4-amino-3-trifluoromethylpheno (RTFM) l, a stable compound. Organisms are able to reduce RTFM further through glucurinidation, a metabolic process commonly used to expel toxins through the liver. UDPGT is the enzyme directly responsible for the glucurinidation and has been shown to be relatively inactive in sea lamprey. Enzyme analysis showed that most aquatic species found in the Great Lakes have a higher enzymatic affinity of UDPGT (uridine diphosphoglucuronyltransferase) for TFM binding than sea lamprey (Kane et al, 1994). Without the binding of UDPGT to TFM, the chemical persists and causes mortality. TFM and Lamprey Control The mechanism by which TFM kills sea lamprey larvae is directly related to ATP supply and demand. Research done by Wilkie et al. (2007) showed that TFM directly interferes with the metabolic pathway. The results of this research evidenced an LC50 of 1.6 mg L -1 over 12 hours. The chemical phosphocreatine (PCr) is a precursor to ATP in the metabolic pathway and is required to provide the third phosphorus making ADP to ATP. After 3 hours of exposure to TFM the concentration of PCr dropped significantly (Figure 5). After 6 hours tissue lactate had risen 10-fold and remained stable for the last 6 hours of exposure. The increase in tissue lactate suggested that PCr depletion had occurred to such levels that anaerobic glycolysis was required to maintain ATP production.

11 11 Figure 5. (a) The concentration of ATP in sea lamprey during a 12hr exposure to TFM varied insignificantly (Wilkie et al., 2007). (b)the concentration of PCr, a precursor to ATP production, was shown to decrease in sea lamprey during a 12 hr exposure to TFM (Wilkie et al., 2007) Targeting larval lamprey allows for the concentration of TFM used to be lower than otherwise necessary because of the particular inability of the larval lamprey to detoxify the chemical. Wilkie et al. (2007) found that a correlation was present between body size and vulnerability to TFM. By selecting exposure to be during the larval stage during optimal vulnerability reduces the amount of TFM used overall. Dr. Ellen Marsden (2010) confirmed that the mechanism by which TFM is most selective for sea lamprey is largely unknown. The study from Wilkie et al. (2007) is one of the few published articles that have investigated the specific biological process that lead to lamprey mortality. While it is generally accepted that TFM is a non-persistent, low impact chemical, the long-term effects of extended and repeated application to aquatic systems is not known. Non-Target Effects of TFM One of the original reasons that TFM was used as a method for controlling lamprey populations was because previously used physical means resulted in higher rates of non-target mortality than TFM did (McDonald and Kolar, 2007). However, since TFM s origin in the 1960 s many questions have arisen about its effects on non-target organisms. While TFM has been shown to be most toxic on lamprey, it can be lethal to other aquatic organisms in varying concentrations. Members of the Catfish family (Ictaluridae) are some of the most sensitive, showing effects at just 1.3 to 1.5 times the minimum lethal concentration (MLC) for lamprey. Other organisms sensitive to these concentrations of TFM include juvenile lake sturgeon (Acipenser flvescens) and adult mudpuppies (Necurus). Most Salmonid species have been shown to have MLCs at 3 to 5 times that of lamprey, while many Centrarchidae and Percidae species have MLCs of 6 to 8 times that of lamprey (Brege et al., 2003).

12 12 Of all of these species though, lake sturgeon have been shown to be one of the most sensitive non-target organisms. The Lake Sturgeon is a threatened species in the Great Lakes, and already have small populations. Additionally, they spawn in many of the same stream tributaries that lamprey do, and thus are directly exposed to TFM treatments. In laboratory exposure experiments, TFM has been found to be more lethal to lake sturgeon than to sea lamprey during certain life stages, particularly in the fry stage. At older stages lake sturgeon show similar MLCs to that of lamprey (Boogaard et al., 2003). It is thus important that we continue to monitor sturgeon populations in the Lake Champlain Basin, and especially in areas where TFM is used. Another particularly sensitive species is the mudpuppy (Species Necurus). These amphibians spend all of their lives in water. Mortality rates as high as 32% in Lake Superior Tributaries and 36% in Lake Michigan Tributaries were observed in streams treated with TFM (Boogaard et al., 2003). Laboratory tests have shown that No Observable Effect Concentrations (NOEC) of TFM for mudpuppies is higher than MLC levels for lamprey. Yet, TFM applications are imprecise, and concentrations do vary in the field and are higher than advised (Brege et al., 2003). For instance, in October 2009 a TFM application in the Lamoille River killed off hundreds of mudpuppies, even though the concentration used was not supposed to affect the amphibians (Times Argus 2008). Most articles in the peer-reviewed literature indicate that more studies need to be conducted on the non-target effects of TFM, especially on sedentary and endangered species (McDonald and Kolar 2007, Waller et al., 2003). Even after over 40 years of use little is still known about the unintended effects of TFM on ecosystems. Cost-benefit analysis In order for sea lamprey control to be acceptable we must evaluate a cost-benefit analysis concerning the use of TFM. A cost-benefit analysis will weigh the treatment of lampricide in regards to the economic cost of the treatment and the effectiveness on our target species, sea lamprey. For a cost-benefit analysis to be accepted TFM treatment must explicitly control sea lamprey in their juvenile stages within streams or rivers, and at the same time be economically feasible. The term economically feasible can be attributed to many factors not exclusively monetary values. Some factors include funding and the public s perception of sea lamprey. For example, will the public indicate the importance for sea lamprey control in comparison to other potentially significant situations surrounding ecosystems and the environment? Cost benefit analyses involving the application of lampricide indicate that it may not be economically effective. One study by Zerrenner and Marsden (2006) indicates that sample streams using TFM treatment to control sea lamprey actually indicate faster maturation from larval stages to transformers than non-treated streams. The cost benefit ratio for a long-term study could suggest that it is not in the favor of the state to treat sea lamprey with TFM. Application of lampricide could create conditions where sea lamprey are adapting and evolving to the introduction of the chemical, thus possibly building a biological resistance. Sea lamprey may also reach the transformer stage (transitional period where sea lamprey exit there sedimentary stage and begin to increase in size in preparation to enter open water, i.e. the lake) at a younger age indicating that the application of TFM will need to increase (Zerrenner and Marsden 2006). It is possible that as government funding is being cut, increased application of TFM may not be an economically viable option.

13 13 In opposition to the previous study, there is evidence justifying the treatment of sea lamprey using TFM. In a 1990 study specialists conducted a cost benefit analysis of the effects of lampricide in the Lake Champlain Basin. The study was accomplished by individuals representing the University of Vermont s School of Natural Resources, the Vermont Department of Fish and Wildlife, the New York DEC Bureau of Fisheries and the U.S. Fish and Wildlife Service. According to a cost-benefit analysis of the Eight-year Experimental Sea Lamprey Control Program on Lake Champlain, sea lamprey control generated benefits of approximately $29.4 million with costs of about $8.4 million, a benefit to cost ratio of 3.5 to 1 (NYDEC 2010). The benefit values were derived from the local economy surrounding the lake, which is heavily contributed to by anglers. The lake holds numerous large scale fishing tournaments to include the popular Father s Day Lake Champlain International Derby. The lake even hosts tournaments at the professional level. This tournament is called the Bass Masters Classic and attracts large crowds. The revenue from these events, resident/nonresident fishing licenses, fishing/boating supplies and also fish chartering services make up the majority of the $29.4 million in benefits. Recommendations We recommend that continued application and treatment of the lampricide TFM should be partnered with in-depth monitoring of the impacts on non-target species such as Lake Sturgeon and Mudpuppies. Specifically, the biological differences in how TFM is processed by non-target species should be studied to see if chemical modifications could be made to make TFM more selective for sea lamprey. In addition, we recommend that the number of lamprey wounds on sport fish species should continue to be monitored, along with the used of lampricide application. We do not believe there is evidence to suggest that TFM is a significant danger to any species if applied as directed by experts. Proper application of TFM should include adequate background knowledge of the aquatic system, including ph, alkalinity, and presence of those non-target species most vulnerable to the chemical. Additionally, the procedures outlined by McDonald and Kolar (2007) should be followed to make sure professionals have a thorough understanding of the mechanisms of TFM and the factors that can impact its effectiveness. Although there are alternatives to TFM such as physical barriers, use of pheromones and introduction of sterile males we do not believe these techniques to be as effective as the use of TFM. Acknowledgements We would like to thank Dr. J. Ellen Marsden for providing us with background knowledge and expertise on sea lamprey control and the effectiveness on TFM. Additionally, we would like to thank Dr. Marsden and Dr. Stephanie Hurley for providing us articles for this report. We would also like to thank Dr. Hurley and Lisle Snyder for support and editing our paper.

14 14 Literature cited Boogaard, M. A., Bills, T.D., & Johnson, D.A. (2003). Acute Toxicity of TFM and a TFM/Niclosamide Mixture to Selected Species of Fish, Including Lake Sturgeon (Acipenser fulvescens) and Mudpuppies (Necturus maculosus), in Laboratory and Field Exposures. Journal of Great Lakes Research, 29(1), Bothwell, M.L., Beeton, A.M., & Lech, J.J. (1973). Degradation of the lampricide 3- trifluoromethyl-4-nitrophenol by bottom sediments. Journal of Fisheries Research Board of Canada. 30, Bryan, M. B., Zalinski, D., Filcek, K. B., Libants, S., Li, W., & Scribner, K. T. (2005). Patterns of invasion and colonization of the sea lamprey ( Petromyzon marinus ) in North America as revealed by microsatellite genotypes. Molecular Ecology, 14, Retrieved March 12, Brege, D.C., Davis, D.M., Genovese, J.H., McAuley, T. C., Stephens, B. E., & Westman, R.W. (2003). Factors responsible for the reduction in quantity of the lampricide, TFM, applied annually in streams tributary to the Great Lakes from 1979 to Journal of Great Lakes Research, 29(1), Carey, J.H & Fox, M.E. (1981). Photodegredation of the lampricide 3-trifluoromethyl-4- nitrophenol (TFM). Journal of the Great Lakes, 7, Fathulla, R.N. (2001). Artificial sunlight photodegredation of 14C-labeled 3- trifluoromethyl-4-nitrophenol (14C TFM) in aqueous buffer solutions and lake water. Hazlteon Laboratories, Inc. Madison, Wisconson. Unpublished report submitted to the U.S. Environmental Protection Agency. Fisheries Technical Committee. (2009). Strategic Plan for Lake Champlain Fisheries. Lake Champlain Fish and Wildlife Management Cooperative, USFWS, Essex Junction, VT. Retrieved from Hubert, T.D. (2003). Environmental Fate and Effects of the Lampricide TFM: a Review. Journal of Great Lakes Research, 29(1), Johnson D.A., & Stephens B.E., Historical Perspective on the development of procedures for conducting on-site toxicity tests and for measuring concentrations of lampricides in the sea lamprey control program during Journal of Great lakes Research, 29(1), Kawatski, J.A. & Bittner, M.A. (1975). Uptake, elimination and biotransformation of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) by larvae of the aquatic midge Chironomus tentans. Toxicology, 4,

15 15 Kane, A.S., Kahning, M.W., & Reimshuessel, R. (1994). UDP-glucuronyltransferase kinetics for 3-3-trifluoromethyl-4-nitrophenol (TFM) in fish. Transaction of the American Fisheries Society, 123, Lake Champlain Basin Program. (2008). Aquatic Nuisance Species in Lake Champlain and the Basin. Retrieved from Lake Champlain Basin Program. (2008). State of the Lake and Ecosystem Indicators Report. In print. Lake Champlain Basin Program. Threatened and Endangered Animals in the Lake Champlain Basin. Updated July Retrieved 16 March 2010 from Maki, A.W. & Johnson, H.E. (1977). Kinetics of lampricide (TFM, 3-trifluoromethyl-4- nitrophenol) residues in model stream communities. Journal of Fisheries Research Board of Canada. 34, Marsden, J. E., Chipman, B. D., Nashett, L. J., Anderson, J. K., Bouffard, W., & Durfey, L. (2003). Sea lamprey control in Lake Champlain. Journal of Great Lakes Research, 29, Marsden, Ellen. Personal Interview. 17 March McDonald, G.D., & Kolar, C.S. (2007). Research Guide to the Use of Lampricides for Controlling Sea Lamprey. Journal of Great Lakes Research, 33(2), New York Department of Environmental Conservation. (2010). Lake Champlain Sea Lamprey Control Retrieved March 16, 2010 from New York: Department of Environmental Conservation (2010). Sea Lamprey Impacts. Retrieved from New York Department of Environmental Conservation., & Vermont Department of Fish & Wildlife Service. (2001). Draft supplemental environmental impact statement: a long-term program of sea lamprey control in Lake Champlain (Draft 1 ed.). Essex Vermont: U.S. Fish and Wildlife. Porter, Lewis. Lampricide kills hundreds of salamanders in Lamoille River. Times Argus Online. Published 9 October Accessed 18 April Schultz, D.P., Harman, P.D. & Luhning, C.W. (1979). Uptake, metabolism and elimination of the lampricide 3-trifluoromethyl-4-nitrophenol by largemouth bass. Journal of Agricultural and Food Chemistry. 27, Smyth, R. L., Watzin, M. C., & Manning, R. E. (2007). Defining acceptable levels for ecological indicators: an approach for considering social values. Environmental Management, 39,

16 16 USGS: Great Lakes Science Center. (2008). Invasive fish: Sea lamprey. Retrieved from &menu=research_invasive_fish Waldman, J. R., Grunwald, C., & Wirgin, I. (2006). Evaluation of the Native Status of Sea Lampreys in Lake Champlain Based on Mitochondrial DNA Sequencing Analysis. Transactions of the American Fisheries Society, 135, Retrieved March 12, 2010, from the Web of Science database. Waller, Diane L., Bills, Terry D., Boogaard, Michael A., Johnson, David A., & Doolittle, T.C.J. (2003). Effects of Lampricide Exposure on the Survival, Growth, and Behavior of the Unionid Mussels Elliptio complanata and Pyganadon cataracta. Journal of Great Lakes Research, 29(1), Wilkie, M.P., Holmes, J.A., & Youson, J.H The Lampricide3-trifluoromethyl-4- nitrophenol (TFM) interferes with intermediary metabolism and glucose homeostasis but not with ion balance, in larval sea lamprey (Petromyzon marinus). Canadian Journal of Fisheries and Aquatic Sciences, 64, Zerrenner, A., & Marsden, J. E. (2006). Comparison of Larval Sea Lamprey Life History: Characteristics in a Lampricide-Treated Tributary and Untreated Tributary System of Lake Champlain. Transactions of the American Fisheries Society, 135,