Silent Invaders: Biodiversity Decline as a Result of Zebra and quagga Mussel Over Population

Transcription

1 Silent Invaders: Biodiversity Decline as a Result of Zebra and quagga Mussel Over Population A Historical Study of Eurasian Mussels in the North Country and Preventing their Spread Out West Madelyn T. Gilroy Carlie A. Wright Biology Department St. Lawrence University 23 Romoda Drive Canton, NY Photo Credit: 1

2 2

3 TABLE OF CONTENTS LIST OF TABLES AND FIGURES... 7 EXECUTIVE SUMMARY... 8 INTRODUCTION METHODS INTERVIEW SUBJECTS...20 PROBLEM DEFINITION BALLAST WATER:...22 BIOLOGY OF ZEBRA MUSSELS AN QUAGGA MUSSELS...23 BIODIVERSITY IMPACTS:...26 Algal Blooms...26 Outcompeting Native Mussels:...28 Diets...30 HUMAN IMPACTS ON BIODIVERSITY LOSS:...31 IDENTIFICATION OF STAKEHOLDERS RESIDENTS:...34 RECREATION INDUSTRY:...36 GOVERNMENT OFFICIALS:...37 COMMERCIAL WATER INDUSTRIES:...38 Hydro- Electrical industries:...38 Water industries (municipal supplies):...40 INVASIVE SPECIES SCIENTISTS:...40 WATER- TRANSPORTATION INDUSTRY:...41 iii

4 GOVERNMENTAL ISSUES BALLAST WATER REGULATIONS...44 CLEAN BOATING ACT...45 ECONOMICS:...46 RECREATION RESTRICTION...47 DEVELOPMENT OF SOLUTIONS TO THE PROBLEM PARAMETERIZING SOLUTIONS...48 NORTH COUNTRY FAILURES...48 IDENTIFICATION AND EVALUATION OF POTENTIAL SOLUTIONS...50 Zequanox (Closed System Solution):...50 Open- system solution:...51 Potassium Chloride:...52 Zebra mussel traps:...52 Introduce the predator the Black Carp:...53 Boat Cleaning:...53 Ballast Water Regulations:...54 Education:...55 IDENTIFICATION OF FEASIBLE SOLUTIONS:...55 Potassium Chloride Potash :...55 Zequanox:...56 Zebra mussel traps:...56 Boat Cleaning:...56 Education:...56 Ballast Water Treatment:...57 iv

5 IDENTIFICATION OF BEST SOLUTIONS...57 EASE OF IMPLEMENTATION ZEQUANOX...59 BOAT CLEANING...59 EDUCATION...60 IMPLEMENTATION PLAN CONCLUSIONS ACKNOWLEDGEMENTS LITERATURE CITED Karatayev A, Burlakova L, Mastitsky S, Padilla D Predicting the spread of aquatic invaders: insight from 200 years of invasion by zebra mussels. Ecological Applications 25(2): TABLE AND FIGURE CITATIONS APPENDICES APPENDIX A: INTERVIEW QUESTIONS...75 v

6 6

7 LIST OF TABLES AND FIGURES Figure 1: Concept map of Zebra and quagga mussel invasion...8 Figure 2. Zebra Mussel invasion in the Great Lakes System.. 9 Figure 3. Distinction between Zebra and quagga mussels 10 Figure 4. Calcium levels throughout the United States and established zebra and quagga mussel populations (Whittier et al 2008)...11 Figure 5. Lake Champlain food web...14 Figure 6. USGS calculated populations of zebra and quagga mussels..16 Figure 7. Invasive species curve 15 Figure 8. Life cycle stages for Zebra and quagga mussels 21 Figure 9. Food web showing the effects of zebra mussels on nutrient cycling Figure 10. Phosphorous levels in Lake Champlain Figure 11. Zebra and quagga mussels clogging pipes

8 EXECUTIVE SUMMARY For nearly two decades biodiversity in the North Country in Northern NY has been threatened by zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena bugensis), here forth referred to together as Eurasian mussels. These invasive Eurasian mussels were first introduced into the Great Lakes in the late 1980s before making their way to the St. Lawrence River in Since 1991, these Eurasian mussels have been wreaking havoc on our most treasured water bodies. In this report, we are focusing on the introduction of Eurasian mussels into the St. Lawrence River, Lake Champlain and a couple of the Great Lakes (specifically Lake Erie and Lake Ontario). These water bodies have seen dramatic changes over the last two decades as a result of increasing Eurasian mussel populations, including changes in ecosystem composition. Eurasian mussels are filter feeders consuming the tiniest organisms, phytoplankton, in water bodies. At first glance, this would appear to be beneficial. Clearer water means greater recreational use of the lake, however clearer water also means that the composition of the lake ecosystem is changing. By decreasing phytoplankton levels, Eurasian mussels will be responsible for decreasing zooplankton and planktivorous fish stocks as well (Colvin et al. 2015). Eurasian mussels do not eat blue-green algae; also known as cyanobacteria, when filter feeding. The increase in blue-green algae therefore increases the algal blooms on our lakes and rivers (Stallard 2015). These algal blooms release toxins into the water that create a lower ph. This increase in acidity and toxicity can kill native fish species living in the water body. Native mussels are also at risk of decreasing because Eurasian mussels will outcompete their food source and suffocate native mussels by using them as a hard surface to grab on to with their byssal threads (Colvin et al. 2015). 8

9 Along with biodiversity loss there comes a great economic, social and governmental price to controlling Eurasian mussels. The US government has spent upwards of 5 billion dollars trying to control the species since its first introduction into North America in the late 1980s (USGS 2016). For the last decade, the Federal government and New York State government have been working hard to prevent the future introduction of invasive species into shipping ports on the east coast by increasing ballast water regulations. The government at a federal level in the United States has also passed regulations entitled The Invasive Species Act as well as the Clean Boating Act, which together work towards decreasing the likelihood of spread and establishment of Eurasian mussels and other invasive species into water bodies throughout the United States. As we have seen throughout our research, there is no fix all solution when it comes to controlling Eurasian mussels from spreading. The increased use of a the pesticide Zequanox, along with prevention education and maintaining strict ballast water regulations across the country remain the best ways in which the Eurasian mussels can be controlled. There have been many failed prevention and eradication techniques in the North Country, as this is where the introduction first occurred. However, the purpose of this paper is to recognize these failures and to stress the importance of prevention education on the West Coast. The less the Eurasian mussels spread the less damage they will be able to do to the lakes and rivers across the continent (Figure 1). The North Country may no longer be at a place where eradication is feasible, however with the proper control mechanisms the population of Eurasian mussels can at least be slowed down and will have less effects on biodiversity in our lakes and rivers. 9

10 = Figure 1. Concept Map of zebra and quagga mussel invasion into the United States. 10

11 INTRODUCTION Zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena bugensis) originated in the Caspian Sea near northern Iran and Russia (nps.gov 2016). In the 1700s they migrated to Europe through popular trade routes by hitchhiking a ride on large cargo ships. These Eurasian mussels were transported through ballast water. When shipping vessels were leaving Iran and Russia to pick up goods in Europe they balanced the ship by using ballast water from the Caspian Sea. Once arriving in port the water would be removed as the cargo was loaded, releasing hitchhiking larvae into European waters (Karatayev et al. 2015). Once established in Europe it took over a hundred years for Zebra mussels to migrate to North America despite continuous trade. One reason for this stall in expansion was, that up until the 1900s solid ballast was used for North American shipping, which decreased the transport of aquatic organisms (O Neill 1994). Zebra and quagga mussels are freshwater organisms and can only withstand salinity levels up to 3ppt (O Neill 1994). The average salinity levels between Europe and the Americas is about 25 ppt making it impossible for these invasive mussels to travel on the outside of the ship (Gilroy 2015). This life history characteristic decreased the likelihood of Zebra and quagga mussels becoming established in North America. It wasn t until 1959 when the St. Lawrence Seaway was constructed connecting the Great Lakes to the open ocean through a system of locks and canals that the likelihood of these mussel becoming established increased (Sussman 1978). From that point on oceangoing vessels were transporting cargo to lake ports where salinity levels would be suitable for Zebra and quagga mussels and realizing their ballast. In June of 1988 Zebra mussels populations reached noticeable numbers and were discovered in Lake St. Clair near Detroit, Michigan. Due to Lake St. Clair s proximity to the 11

12 Great Lake system (Figure 2) it was only four months before Zebra mussels were discovered in Lake Erie and by the start of the 1990s they were established throughout the Great Lake systems (O Neill 1994). Figure 2. Great Lakes System once affected by Zebra and quagga mussels. Zebra mussels quickly spread to interior lakes like Lake Champlain in 1993 and were fully established in the Mississippi river basin around the same time (NWF 2016). This is due to their unique characteristic that allows Zebra mussels to attach to hard surfaces, like recreational vessels allowing access to other freshwater systems (Karatayev et al. 2015). This characteristic which is often associated with saltwater mussels is not seen in any other freshwater bivalve in the Northern Hemisphere, aside from the Quagga mussel (figure 3)(USGS 2016). 12

13 QUAGGA MUSSEL Figure 3. Differences between Zebra and quagga mussels The Quagga mussel was first sighted in Lake Erie in 1989 and due to being almost behaviorally identical to the Zebra mussel it wasn t until 1991 that they were recognized as separate species (Colvin et al. 2015). The two major differences between these two invasive Eurasian mussels are that the Quagga mussel does not have stripes and are also known for occupying deeper colder water, which allows them greater niche recognition potential (Colvin et al. 2015). Zebra and quagga mussels are almost always researched together and pose the same threats to invade ecosystems. These invasive Eurasian mussels are now present in 29 U.S states and 3 Canadian provinces, due to vessels movement from invaded waterways (USGS 2016). Water composition has been the only preventive force limiting Zebra and quagga mussels expansion. Due to the lack of calcium ions needed for shell growth, waterbodies with soft water are at low risk for invasion (Figure 4) (Whittier et al 2008). Soft water, is water with low ion content due to the absence of dissolved salts that combine with metals like calcium and magnesium (Soft water 13

14 2016). This physical limitation can explain why the St. Lawrence River and Lake Champlain have been Invaded and neighboring water bodies like in the Adirondack have been unaffected by Zebra mussels (Whittier et al 2008). Figure 4. Calcium levels throughout the United States and states at high risk of invasion (Whittier et al. 2008). What has made Zebra and quagga mussels a topic for conservation concern is their invasive characteristics and their ability to destroy a native ecosystem. Due to their fast population growth and lack of predators, they can outcompete native species, which results in a disruption in the local food web (Figure 5) (Karatayev et al. 2015). Zebra and quagga mussels have been known as one of the most aggressive aquatic invasive species, due to their size these mussels can go undetected until population size is too large to eradicate or control (O Neill 14

15 1994). Zebra and quagga mussels are able to expand their population and area rapidly upon invasion due to their planktonic larval stage and ability to reproduce quickly (Karatayev et al. 2015). A female Zebra mussel can produce one million eggs a year (Kaufmann 2012). Zebra and quagga mussels effect on native biodiversity can be seen throughout the food web resulting from a bottom up control model (Karatayev et al. 2015). These Eurasian mussel decrease native mussel diversity and other filter feeding fish by outcompeting them for food and space. Through the reduction of native mussels, predatory molluscivores higher up on the food web are being impacted due to the lack of food and the Eurasian mussels are an inefficient food source. Predatory fish populations are also impacted by these invasive Eurasian mussels due to the absence of population control, which has led to the over consumption of zooplankton (Colvin et al. 2015). Fish and mussels spend their larval stage as plankton and with increased consumption many fish populations higher up on the food web who have adapted lower fecund are being greatly affected. Many of those larger predatory fish are already experiencing pressure from fishing and this added stress from the bottom of the trophic system has potential to collapse the entire aquatic ecosystem. 15

16 ~ _ ::_!'.;) -~ - _A Figure 5. Food web of Lake Champlain. Over the past two decades, researchers have developed extensive knowledge on these invasive mussels. Several possible control mechanisms have been put in place over the last several years. However nothing seems to be slowing this invasive species problem in the North Country. What has been seen in the North Country is that people have started accepting Zebra and quagga mussels as a part of the ecosystem, and have decreased efforts on eradication. Instead most stakeholders have developed a system of maintenance management seen in the commercial water and recreation industry giving up hope on restoring the ecosystems biodiversity. 16

17 Zebra and Quagga Mussel Sightings Distribution Dreissena potymorpha and D. rostriformis bugensis Map produced by the U.S. Geological Survey, Nonlndlg~no s Aquatic Species Oatabas o Quagga mussel occurrences 0 Both species occu rrences Zebra /Quagga mussels eradicated C:: Zebra/Quagga mussels failed Figure 6. Zebra and quagga mussels distribution in North America as of March 30th 2016 (USGS 2016) Due to the decreased eradication effort the invasive Zebra and quagga mussels are not publicly seen as a problem in the North Country anymore. However, as long as waterbodies in the North Country are invaded these invasive Eurasian mussels will continue to impact biodiversity the same today as they have been for the last two decades (Figure 5). The United States is a country connected by watersheds making the transfer of zebra and quagga mussels likely to occur continually. Currently the west coast is a decade behind the Northeast on the Eurasian mussel invasion and if implemented correctly could use knowledge and products already developed to fight and prevent invasion. The Northeast has been at the forefront for Zebra and quagga mussel research and developed products like ballast water filtration treatment systems and Zequanox (refer to solutions section for more information) to reduce environmental 17

18 costs of this invasive. What makes the West Coast so vulnerable to this invasive mussel issue is the high calcium concentrations (Figure 4), and how connected their waterways are (much like the Mississippi river basin). Due to the high risk of invasion it is extremely important this issue is addressed before it is too late. One aspect of this case study is to determine the importance of prevention and awareness when it comes to invasive species (Figure 7). The sooner the public becomes aware the easier it will be to eradicate the populations that have been established. Figure 7. Invasive Species Curve This case study will examine how biodiversity has declined as a result of the Zebra and quagga mussel overpopulation over the past 2 decades as well as consider some possible solutions for eradication and population control. Throughout this paper we will define ways in which the West Coast of the United States can prevent the same catastrophic event from 18

19 happening to them that we have observed in the North Country. We will do this by identifying the stakeholders (residents, recreational users, government officials, hydro-electrical industry, transportation, and scientists) and researching the problems they have had as a result of this invasion. The seven goals of this case study are: 1. Summarize the history of invasion in the Northeast. 2. Determine what has been done to eradicate or control the species. 3. Determine the most effective and sustainable methods of population control/ eradication. 4. Show the power of how invasives can change an ecosystem 5. Describe the ways Zebra Mussels impact humans 6. Determine the economic cost of controlling or eradicating Zebra Mussel 7. Show how this problem can be prevented with early detection and interception. 19

20 METHODS To conduct our case, we directed our research towards Lake Champlain, the St. Lawrence River and a couple of the Great Lakes (specifically Lake Erie and Lake Ontario) (Figure 2). To gather information we looked at primary scientific journals, newspaper articles, YouTube videos, documentaries and podcast. Each type of resource provided us with a different perspective on the topic, whether that be the science behind Eurasian mussels and the destruction they cause environmentally or the social impacts that they are having on the surrounding human populations. We also conducted a series of interviews in the month of March These interviews were with people whom are experts on their topic and also people that we found could supply us with extra information on what we were finding through the literature. Interview questions can be found in appendix A. E Draw max was used to create the concept map (Figure 1) for this case study. Interview Subjects Dr. Brad Baldwin: Dr. Baldwin is a Professor of Biology at St. Lawrence University who has experience researching Eurasian mussels in the North Country. His interview gave us a better view as to what the problem is specifically near St. Lawrence County. His interview also gave us an interesting perspective as to why the Adirondacks have not (yet) been infiltrated by Eurasian mussels in some of the larger lakes and rivers. Anastasia Burdock: An important aspect of this case study is understanding the residential opinion. Mrs. Burdock supplied us with the understanding of how Eurasian mussels 20

21 have impacted her recreational use of Lake Champlain, including impacts such as cutting her feet, using her boat, and having to follow strict regulations on cleaning her boat after use. Larry Eichler: Mr. Eichler is a research scientist at Rensselaer Polytechnic Institute specifically working with the Darrin Freshwater Institute on Lake George. Though we did not specifically look at Lake George in our case study, Mr. Eichler was able to provide us with ways in which Eurasian mussels have affected inland lakes, as it is not just an issue at shipping ports. Dr. Daniel P. Malloy: Dr. Molloy is an Adjunct Professor of Biology at the University of Albany and has worked on Eurasian mussel overpopulation since their first introduction in the late 1980s. His field of expertise is controlling the species specifically with his own solution, Zequanox. Zequanox is a useful solution to the problem of Eurasian mussel overpopulation, but later we discuss why it has yet to be widely used. Dr. Molloy s interview gave us a better grasp of what has actually been done in order to keep the Eurasian mussel population under control throughout the last couple of decades. Ted Snieckus: Mr. Snieckus is a US Naval Third Mate who specializes in large cargo ship transportation. His interview was critical in understanding the rules and regulations that cargo ships have to undergo in order to exchange ballast water (a known contributor to the invasive problem) and other aspects of how Eurasian mussel overpopulation has impacted transportation in and out of the United States. Each of these interviews provided us with an opinion and knowledge that we would otherwise have been unable to find in the literature. 21

22 PROBLEM DEFINITION Ballast Water: Ballast water is water that is taken on by a vessel to compensate for changes in the vessel s weight as cargo is loaded or unloaded, and as fuel supplies are consumed. On a global scale, commercial shipping transports approximately 2/3 of world trade based on tonnage and requires the discharge of 3.5 billion tons of ballast water each year (Stallard 2015). When a vessel takes on ballast water, whether freshwater or saltwater, organisms found in that water are typically taken on as well. These organisms, often referred to as aquatic nuisance species, are carried in the ballast tanks of vessels until the vessel arrives at its next port where, due to changes in distribution of the vessel s cargo, the organisms may be realized into a new ecosystem, establish viable populations, and prey on or outcompete indigenous species (Stallard 2015). Examples of invasive species that have been introduced into New England though ballast water include, zebra and quagga mussels, shipworms and green crab. These species were all introduced before the United States placed stricter regulations on ballast water, those regulations currently stating that ballast water exchange must occurring no closer than 200 nautical miles from the shoreline in water depths no less than 2000 m (Snieckus, personal communication) 1. The ships as a whole are not regularly cleaned. The inside tanks are cleaned periodically but externally, the hull is all that is really cleaned on the ship. The hull needs to be cleaned in order to keep the boat moving quickly and efficiently through the water, yet the rest of the exterior of the ship is often ignored (Snieckus, personal communication) 2. These before 1 Ted Snieckus, Interview 15 March, Ted Snieckus, Interview 15 March,

23 mentioned ballast water regulations included vessels to update their ballast water tanks to make them easier to clean (Tuxil 2016), however many boats were given extensions on updating their systems because of cost of doing so. By not all shipping vessels being able to update their ballast water tanks to regulation standards, there is still potential for invasive species to still be transported into new territory, like the Eurasian mussels. Biology of Zebra Mussels and Quagga Mussels These Eurasian mussels belong to the kingdom Animalia, phylum Mollusca and class bivalvia. Zebra and quagga mussels are benthic filter feeders, using siphons; Eurasian mussels filter food particles from water. (Colvin et al. 2015). Average-sized adult Eurasian mussels filter about 1.5L of water a day, resulting in rather clear water systems. Eurasian mussels are picky eaters, consuming only the best phytoplankton and leaving phytoplankton exposed to cyanobacteria out of their diet (Mayer et al. 2001). The mussels themselves are not large, reaching only the 5 mm or more commonly the size of a thumbnail in their adult form (Meyer et al. 2001). Overpopulation of these Eurasian mussels have been the major cause for concern with biodiversity decline in North Country lakes and rivers. Zebra mussels alone have a fecundity one million eggs per adult female per year (Griffiths et al. 2011). Eurasian mussels live between 3 and 5 years. Important to keep in mind throughout this case study is the life cycle of both quagga and zebra mussels. There are three main periods in the zebra mussel life cycle: the larval, juvenile, and adult stages (Figure 8). The larvae are planktonic (float in water column) during their initial three life stages: trochophore, straight-hinged veliger, and umbonal veliger. Larvae eventually settle on a substrate during their pediveliger stage, and move only by crawling during their 23

24 plantigrade stage. The pediveliger is considered by some to be the final larval form, with the plantigrade as a stage between larval and juvenile stages (Colvin et al. 2015). Figure 8 Life cycle stages for zebra and quagga mussels. Eurasian mussels have traditionally preferred cooler water temperatures, making them a nuisance in the North Country. However, as the mussels spread out west they have been adapting to warmer temperatures (Griffiths et al. 2011). Eurasian mussels tend to enjoy water temperatures hovering around 28 C, anything much warmer and the mussels will begin to die (USGS, 2016). As the Eurasian mussels have begun to move out west they have begun to adapt to the warmer water. This spread into warmer water jeopardizes a large portion of the country after their North Country invasion. As the mussels move west into California it is also a major risk that they will also move south. 24

25 Quagga mussels and zebra mussels have a similar biology in terms of their life cycle and their eating patterns. Both of these mussels remove phytoplankton as noted by 80% and subsequently also decrease zooplankton by 71%, these decreases dramatically alter the food web in our lakes and rivers (Figure 9). Quagga mussels accumulate organic pollutants within their tissues to levels more than 300,000 times greater than concentrations in the environment and these pollutants are found in their pseudo feces. Pseudo feces is everything that the mussels cannot consume for their health. These pollutants will be accumulated up the food chain as fowl eat the zebra mussels, especially migratory birds (Snyder et al. 1997). Figure 9. Food web showing nutrient cycling done by zebra and quagga mussels. 25

26 In North America, Eurasian mussels have limited predators. It is seen that migratory birds and diving ducks will actually eat the mussels but not at a rate that will maintain their populations (Boyle 2015). When populations get out of control it is found that any hard surface in the lake or river (including the floor of the water body) can be covered with upwards of 2 inches worth of these Eurasian mussels (Boyle 2015). By covering surfaces the mussels will not only outcompete native mussel species but also cause blockages in pipes along waterfront industry. Without enough natural predators, a high fecundity and the ability to glue themselves to surfaces along with being a vector for organic pollutants, Eurasian mussels have had detrimental effects on biodiversity within the North Country and are expected to continue this invasion as the mussels move out west. Biodiversity Impacts: Algal Blooms As Eurasian mussels do not consume blue-green algae (cyanobacteria) while filter feeding, harmful toxins are accumulated into the water (Stallard 2015). Algal blooms in NYS have always been an issue due to agricultural runoff, however with the overpopulation of Eurasian mussels these algal blooms have nearly doubled in frequency (Stallard 2015) (Figure 26

27 10). Figure 10. Phosphorous increases in Lake Champlain. Selective filtration by Eurasian mussels is responsible for lake-wide increases in Microcytic and may also be a partial explain for the long-term decline in Anabaena, because this genus does not form large colonies. The change in algae represented in Lake Erie is echoed in Lake Champlain and similar water bodies (Connerton et al. 2006). Algal blooms can consume dissolved oxygen from the lake resulting in large fish kills in the affected area (Higgins and Zanden 2011). There has not been enough research done on the local North Country waterways to determine the actual effects of these algal blooms as of 2016 but rather expected results, including greater water toxicity and a lower ph. As the water becomes more inhabitable there will be a decrease in small and large fish alike, especially if the ph falls below 5 (Higgins and Zanden 2011). 27

28 It is believed that beds of the invasive quagga and zebra mussels that are now common in the Great Lakes provide a medium in which the cyanobacteria thrive. When fish, especially another invasive species, the round goby, feed on the mussels, they take up the bacteria and its neurotoxin. If birds consume those fish, the toxin poisons the birds. They typically are paralyzed and drown in the water (Orr 2015). In order for the lakes to be properly monitored for these algal blooms for the prevention of biodiversity loss of fish and fowl, the lakes need to be shut down from recreational use. Cyanobacteria can be consumed up the food chain leading to bioaccumulation, threatening the larger species that residents of the lakes and rivers have grown fond of. Bioaccumulation starting with the smallest of organisms, like the zebra mussels, will lead to greater issues higher up the trophic cascade and increase mortality of larger planktivorous fish and predators to the Eurasian mussels. Outcompeting Native Mussels: Freshwater mussels (Order Unionoida) are the most imperiled faunal group in North America; 60% of described species are considered endangered or threatened, and 12% are presumed extinct (Ricciardi et al 1996). Eurasian mussels have outcompeted 8 of 14 total native mussels in the Lake Champlain basin (Benson 2015). Eurasian mussels will decrease phytoplankton stalks, outcompeting a food resource, and they will suffocate the native mussels while competing for hard surfaces to establish themselves on. Giant Floater (Pyganodon grandis), Pocketbook (Lampsilis ovata), Pink Heelsplitter (Potamilus alatus), Fragile Papershell (Leptodea fragilis), Black Sandshell (Ligumia recta) are 5 of the 8 critically endangered native mussels in the Lake Champlain basin. In the St. Lawrence River mussels belonging to the families Unionidae and Margaritiferidae are amongst the highest risk for being outcompeted by 28

29 Eurasian mussels. Eurasian mussels will attach themselves to the shells of native mussels, suffocating them (Benson 2015). This means that native mussels will be covered so heavily with zebra mussels that the native mussels will no longer be able to breath. 74% of unionids had been colonized by zebra mussels in the St. Lawrence River, meaning that for every unionid there were 3.1 zebra mussels. By 1996, unionids had decreased by 52% as a result of increased zebra mussel population (Ricciardi et al. 1996). Mortality amongst native species in the St. Lawrence River will see heavy mortality (>90%) when the mass of Eurasian mussels cover the native mussels shells is equal to their own mass or greater (Ricciardi et al. 1996). Eurasian mussels will continue to move throughout the country increasing the risk for native mussels to fall victim to suffocation and starvation. As Eurasian mussels began to outcompete mussels for food resources, native mussels in the St. Lawrence River and the Hudson River declined in body mass by 34% (Strayer and Malcom 2007). This change in the species was caused by a decrease in available food resources for the native mussels and in turn the native mussels had to evolve to being smaller than they were originally. However in the Hudson River, native mussels have made an interesting recovery. The apparent recovery of Hudson River bivalves is consistent with observations of coexistence of unionids and zebra mussels in European waters that were invaded by zebra mussels decades to centuries ago (Strayer and Malcom 2007). The zebra mussels outcompeted the native mussels originally declining their populations to near zero, however once the mussels evolved to be smaller the native mussels were able to make a comeback. Native mussels are not only impacted directly by the decrease in phytoplankton and the need for food resources but they are also impacted indirectly. Native mussels have an extra step in their life cycle that includes a parasitic stage (Mackel 1991). This stage is completed through 29

30 the use of planktivorous fish, like the yellow perch. With a decrease in phytoplankton and food availability leading to a decrease in these planktivorous fish numbers, it will be more difficult for native mussels to complete their life cycle. Therefore, native mussels will be indirectly negatively affected by the increase in Eurasian mussels and decrease in phytoplankton as well. Diets There are several small invertebrates living in water bodies that are often forgotten about. These invertebrates include rotifers, protozoans and nauplii, all of which depend on phytoplankton as a food resource. Rotifers are an aquatic organism belonging to the phylum Rotifera, protozoans are single celled organisms belonging to the phylum protista and a nauplis is the first larval stage of many crustaceans. These microscopic organisms depend on phytoplankton in order to survive and thrive. Sometimes however, these little animals are acting as food resources themselves for Eurasian mussels. One study done on Lake Champlain concluded that rotifer decline was due to direct consumption by zebra mussels rather than through starvation due to lack of phytoplankton (Miller et al. 2007). By consuming more phytoplankton, there has been an increase in Eurasian watermilfoil, a seaweed plant, due to the greater amount of sunlight that can be received with less phytoplankton. Therefore there is a new composition in Lake Champlain in terms of plant species. Eurasian watermilfoil is also an invasive plant to Lake Champlain known to (similarly as Eurasian mussels) outcompete native plants (VPR Interview with Mary Watson, 2012). Eurasian watermilfoil is not as preferred by foragers and waterfowl because it is less valuable as a food resource (VPR Interview, 2012). Eurasian mussels consume phytoplankton in large quantities as well as the larval stage of many invertebrates. There was a pronounced decline (~46%) in phytoplankton bio volume in the St. Lawrence River stocked with Dreissena relative to a reference river lacking mussels 30

31 (Ricciardi et al. 1996). Nauplii, baby crustaceans, are often small enough to be consumed by the Eurasian mussels (Miller et al. 2007). This will lead to fewer of the juveniles reaching adulthood. Sometimes however, the larval stages are too big and escape filtration yet these larvae come to be injured in the process. Injuries in the larval stage lead to higher mortality and are therefore decreasing chances of making it to adulthood (Miller et al. 2007). A pattern that can be seen with Eurasian mussels is that their small impacts on phytoplankton and zooplankton leads to a major decline higher up the trophic cascade. Eurasian mussels were able to go undetected in North Country water bodies for a couple years because they had not affected the larger fish species yet. As the population of Eurasian mussels increased and phytoplankton decreased, there was a clear shift in nutrient cycling leading to greater phosphorous levels. As phosphorous levels rose, there was little available oxygen for larger fish species that created a decline (Higgens and Zandend 2011). In the St. Lawrence River, studies suggest that overlapping diets with mussels will adversely affect growth and perhaps survival of planktivorous life stages of fish through direct competition for the rotifers that are dietary important for many larval fish, and indirect suppression of the phytoplankton which supports many zooplankton species (Thorp and Casper 2003). Yellow perch in its earlier life stages depend on zooplankton and phytoplankton for survival. With an increase in Eurasian mussels leading to a decrease in phytoplankton, it is seen that the perch will decrease as well (Thorp and Casper 2003). Human Impacts on Biodiversity Loss: Globalization has been occurring for centuries. This means that large cargo ships must be used to transport goods throughout the world. Nonnative species, like zebra mussels and quagga mussels, can be introduced into a country via supply ships. However, the likelihood of the nonnative species establishing and becoming a pest are 1/1000. Eurasian mussels were that.001% 31

32 after being introduced via the cargo ship s ballast water tanks in the late 1980s. Yet there are other methods of transportation of Eurasian mussels other than through large shipping. Humans are also known to move around throughout their own country. This would mean that boats can go from one river to another often containing zebra mussels, and can therefore establish themselves in a new river via this mode of dispersal Johnson and Padilla (1996) surveyed boaters in Lake St. Clair after Eurasian mussels had been found in 8 inland lakes in Michigan to. Their results include: adult Eurasian mussels attaching themselves to the exterior hull or to aquatic macrophytes entangling on the trailer or boat exterior and as larvae in live wells, bilges, bait buckets, and cooling systems (Johnson and Padilla 1996). The boaters surveyed provided information as to where they had been boating previously, which was in one of the infested lakes. Of all boaters surveyed, 2.1% reported that they had used both a Great Lake and an inland lake during the two-week survey period. By cross-examination, boaters can be transporting Eurasian mussels to inland water bodies if they are not careful. State parks provide people to connect with nature that may not be available in their daily lives. The benefit of these parks is that the money received as an entrance payment goes towards maintaining that park. As zebra mussels and quagga mussels have started to invade, they have caused a decrease in park use for human safety reasons (Kaufmann 2012). Lakes along Lake Champlain, including Button Bay, were closed for zebra mussel monitoring in the early 2000s while impacts were studied (Kaufmann 2012). While biodiversity decline in lakes and rivers is important for understanding Eurasian mussels, it is also necessary to understand their human impacts to safety as well, leading lakes to close their doors while the spread of zebra mussels and quagga mussels is attempted to be controlled. 32

33 Eurasian mussels often directly impact waterfront industries by impacting infrastructure. The Eurasian mussels can clog water intake structures, such as pipes and screens, therefore reducing pumping capabilities for power and water treatment plants, costing industries, companies and communities (USGS 2016). This leads to the use of chlorine in order to control the problems. Although chlorine itself usually does not cause environmental harm, it combines rapidly to form chemicals such as dioxins, which are chemicals produced as a byproduct in some manufacturing processes (like the removal of Eurasian mussels) that pollute water and contaminate fish (Moore 2016). This is a process of bio magnification; the toxins accumulate as they move up the food chain. Dioxins are not very soluble in water so they will cling to the bottom of the surface and accumulate and have a half-life of more than 500 days. Carcinogens like dioxin have been shown to increase the likelihood of infertility within aquatic organisms seen in Lake Erie (Adedipe 2010). The introduction of carcinogens and dioxins into the water bodies will affect the human health, especially waterfront workers that are exposed to the chlorine for an extended period of time (Molloy 2007). 33

34 IDENTIFICATION OF STAKEHOLDERS When dealing with an invasive species problem, stakeholders play an important role in determining the total impact of the problem because once an ecosystem is invaded its disturbance resilience decreases making it more susceptible to other foreign invaders. A Stakeholder is someone who is directly impacted by the ecological problem, a result of previous investment. There are numerous stakeholders with regards to the Eurasian mussel invasion in North America. The number of stakeholders has only grown in the past two decades as a result of their invasive nature. Among these stakeholders are the lake residents, the recreation industry, government officials, commercial water industries, ecological scientists, and the transportation industry (i.e. shipping). Residents: Residents of the lakes and waterways invaded by Zebra and quagga mussels are important stakeholders in regards to this invasive issue. Residents are directly impacted by the invasion due to the decreased health of the surrounding lake ecosystem and the associated human health and economic impacts. One may argue, that residents benefit from the presences of these Eurasian mussels because they improve the water quality. Though as stated in the problem definition, Quagga and Zebra mussels exclude cyanobacteria when filter feeding, leaving an expanded niche for the toxic algae to flourish, causing increased frequency of harmful algal blooms (HABs) (Figure 10) (Maheen et al. 2013). These HABs have been known to cause human illness (i.e. diarrhea and vomiting, sore throats, liver damage, numbness and tingling, abdominal pain, and skin irritations). The increased concentration of cyanobacteria is what is most troubling because it increases the probability of illness (Cyanobacteria/ Blue-Green Algae 34

35 Facts & Information 2016). Pets are among the most at risk because they are exposed to the highest concentrations through consumption of water and fur absorption. In 1999 the consumption of contaminated water from Lake Champlain resulted in the death of two dogs. These HABs are fast encroaching, one Vermont resident, who has had a house on Lake Champlain for 50 years states in an interview We have never witnessed anything like what we witnessed on Friday, she said. It was crystal clear Friday morning and then within six hours it was thick pea soup. Every hour, it just kept getting thicker and thicker and thicker. (Stein 2012). With the increased frequency of HABs as a result of invasive Eurasian mussels residents fear their waterfront will soon be invaded. Another impact residential stakeholder s face is the associated economic costs as a result of damages due to this Eurasian mussel invasion. Many waterfront residents rely on the surrounding waterbody for water. Since the invasion of zebra and quagga mussels residents are forced to pay large maintenance fees to remove mussels from pipes that are exposed to the water. Many also pay maintenance costs on motors because these Eurasian mussels will attach themselves to any and all hard surfaces. Anastasia Burdock, a tenth generation resident of Lake Champlain, explains that the most common topic of conversation in reference to zebra mussels are their impact on people's feet. Both zebra and quagga mussels have a sharp shell that can leave deep cuts when they come in contact with the epidermis (Zebra mussels 2016). These cuts have been known to cause serious problems to lake residents as well as other lake visitors due to risk of infection. Anastasia 35

36 (Burdock, personal communication) 3 joked about the water shoe industry benefiting in her interview, because swimming shoes are a must in many rocky shore fronts. Residents are among the most important stakeholders because of their emotional connection to the aquatic environment. To reduce risk of future invasion it is up to residents to clean all vessels upon entering and exiting the waterbody. Recreation industry: The recreation industry like residents is directly impacted by the invasion of zebra and quagga mussels for a number of the same reasons and they too hold a stake. The same health risks apply to recreational users as due to residents, though due to increased transportation associated with recreational use, there is an increased risk in transferring these invasives to other lakes. It is the responsibility of the recreation industry to educate users to prevent further transmission and setup boat cleaning stations (Great lakes: understanding the cost of invasives 2015). Scuba divers like recreational boaters play a role and transportation of zebra and quagga mussels and it is extremely important for divers to sterilize equipment after exposure to invasive species because they have potential to transport invaders between wrecks (Johnson 2016). The Scuba diving industry has mixed reviews in regards to the impact of these invasive Eurasian mussels. Due to Zebra and quagga mussels filter feeding characteristic water visibility has increased and many divers can now see more (Johnson 2016). In Lake Erie the visibility has increased by 77%. Though what brings many divers to the waters of the Great Lakes and Lake Champlain are the shipwrecks. With increased water quality the shipwrecks are being spotted 3 Anastasia Burdock, Phone Interview, March 23 rd

37 more easily a more recently emphasized issue is their destruction to them. As stated throughout this case study these invasive Eurasian mussels attach to all hard surfaces. Shipwrecks are now being covered by these invasive mussels, in an interview conducted by the Washington post Brendon Baillod the director of the Milwaukee-based Great Lakes Shipwreck Research Foundation states It is so bad that we can t even see the form of some wrecks, and then goes on to describe the affected wrecks as the most historic and best-preserved wrecks in the world. (Claiborne 2000) With increased distribution of wrecks the future dive industry may be affected. A current debate that as resulted from this issue is whether or not the wrecks should be removed and cleaned of these invasive mussels. Though in order for this to happen it would also take participation of government officials stakeholders because all wrecks belong to a public trust. Government Officials: Government officials are one of the largest stakeholders in dealing with invasive species related problems because they are responsible for responding to social, economic, and environmental issues associated with invasions and take in account all associated stakeholders. It is the job of the government to develop a plan for damage control and generate a possible solution plan to mitigate cost of damages caused by invasive species. Though the only way these laws can be effective is if they are properly enforced. 37

38 Commercial Water industries: Hydro-Electrical industries: Due to the economic, social, and environmental impact of zebra and quagga mussels hydro-electric industries represent a significant proportion of stakeholders in regards to this invasive mussel issue. Since the beginning of industrialization, the utilization of waterways for electricity has been centralized. The invasion of the Eurasian mussels has had devastating impacts on these hydroelectric industries. Zebra and quagga mussels have caused problems by clogging pipes (Figure 11). The effects of these invasive Eurasian mussels penetrates much deeper than a few clogged pipes. These industrial power plants experience many ongoing effects and endure continual maintenance costs as a result of the mussel invasion. Production is affected by scheduled and unscheduled power outages due to cleaning and infrastructural damage. The U.S. Fish and wildlife service predicted in 2012 if Columbia River in Oregon gets invaded the hydro electrical industries maintenance costs could increase by $ million dollars annually (U.S.Fish & Wildlife Service 2012). 38

39 Figure 11. Clogged pipes due to zebra and quagga mussels. In order to combat these invasive mussels, hydro-electric companies have been forced to use chemical control methods to limit population growth throughout their piping systems, but this control method comes with an environmental and social cost. The main chemical used is Chlorine in varying forms (i.e. hypochlorite, chlorine gas, chlorine dioxide) (Meehan et al.2013). Chlorine is effective at minimizing zebra and quagga mussels populations as well as non-target species populations, including the threatened native mussels. Chlorine use poses many health risks and in many facilities requires exposed workers to wear personal protective equipment. With the use of any toxic chemicals extensive regulations are required costing the industry production and money. These regulations include methods for handling and storage of toxic wastes, as well as monitoring concentrations being discarded in the local waterways. These health and environmental risks are often prolonged due to the physiology of the mussel. The mussels, when threatened or stressed, closes their inhalant siphon preventing the filtering of 39

40 chlorine, After prolonged exposure and high concentration the chlorine eventually kills them (Meehan et al.2013). Another characteristic of chlorine that poses an environmental and human health effect is its ability to combine with organic compounds in the water to form carcinogenic substances like dioxins and trihalomethanes (Molloy 2007). These carcinogenic substances have been detected in local waterways even when current discharge regulations are met. Water industries (municipal supplies): Freshwater bodies are vitally important for supplying cities and residents with water for medicinal use. Like the hydroelectric industry the associated health and environmental risks associated with maintenance costs of infrastructure damage, is analogue. Though a risk that poses greater threat to west coast industries, who rely greatly on reservoirs, is the cost of constructing new infrastructure to uninvaded lakes. A Texas article explained that the water industry was forced to increase water bill prices by 14% to absorb the costs of a new pipeline that would bypass Lake Tacoma. Before the lake was invaded by Zebra mussels provided 28% of the area s total water supply (Marks 2013).Many west coast companies are now battling a similar decision, which may also impact residents who may be unaware they are even stakeholders. Invasive Species Scientists: Scientist hold a very import stake when dealing with this invasive mussel problem. It has been through their research that various control methods and potential solutions have arose Invasive species scientists look at the ecosystem as a whole and are able to disclose the potential environmental impacts of a solution. This scientific research has led to a detailed understanding 40

41 of zebra and quagga mussels life history and how they differ from native mussels. Through the mapping of these Eurasian mussel s life cycles scientists were able to determine what water bodies are at greatest risk of invasion. This research gave an explanation for why the Adirondacks State Park has been relatively unaffected by these invasive mussels despite bordering invaded lakes (i.e. Lake Champlain). These Eurasian mussels during their larval stage need high levels of calcium ions in the water to build their calcium carbonate shells (Whittier et al 2008). The Adirondack State Parks water bodies have soft water, meaning it has low ion concentrations, which reduces its risk for invasion because these invasive mussels are unable to complete their life cycle. Government official stakeholders are able to use this scientific research to develop better regulations and to know where to allocate funds, making invasive species scientists extremely important to this invasive mussel problem. Water- Transportation Industry: The water transportation industry is affected by the regulations associated with the invasion of Quagga and Zebra mussels due to the part the industry played in the initial introduction, through the disposal of ballast water. Any ballast water regulation that are past have a significant impact on the water transportation industry because in the United states six ships are docked every minute (Ballast water 2016). Ted Snieckus (Snieckus, personal communications) 4 a U.S. Naval officer that specializes in large supply ship transportation, explains in an interview that the industry has become frustrated with these increased ballast water regulations because of the time and money that is 4 Ted Snieckus, Interview 15 March,