Invasive Species Rainbow Smelt. Includes: Final Report. By Andrew Chard

Transcription

1 Invasive Species Rainbow Smelt Includes: Final Report By Andrew Chard Completed for: OFAH Supervising Professor: Prof. Tom Whillans, Trent University Trent Centre for Community-Based Education Department: Environmental and Resource Studies Course Code: ERST 316 Course Name: Term: Fall/Winter 2008 Date of Project Submission: April, 2008 Project ID: 898 Call Number:

2 Abstract This report presents a synthesis of the current relevant literature on the life history characteristics and impacts associated with invasive rainbow smelt (Osmerus mordax) in Ontario. Rainbow smelt can impact native fish species directly and indirectly through predation and competition. Non-native smelts can directly alter food web structures through predation of native fishes and also compete with other native species for resources (Evans and Loftus 1987). Rainbow smelt also feed at higher trophic levels when compared to native species due to their relatively large gape relative to body length and depth when compared to native forage fish species, which causes more rapid bioaccumulation of toxins (Vander Zanden and Rasmussen 1996). Consumption of high proportions of rainbow smelt has also shown to substantially increase thiamine levels in salmonids, which has been linked to reproductive failures (Elrod et al. 1995, Fisher et al. 1996, Riley and Evans 2008) which further exacerbates the impact of rainbow smelt on native fishes, especially salmonids. Rainbow smelt have had a negative impact on several native fish species including walleye (Sander vitreus), yellow perch (Perca flavescens), and cisco (Coregonus artedi), among others. A brief summary of a predictive model and key environmental variables useful for predicting the future distribution of rainbow smelt is also discussed. Diet In most lakes, rainbow smelt (Osmerus mordax) feed primarily on zooplankton, and dipteran larvae (Chaoborus, Tendipedidae) but also consume aquatic larvae of insects, small crustaceans (Cladocera, Copepoda, Ostracoda) and small fishes including young-of-the-year smelt (Burbidge 1969, Hrabik et al. 1998). Smelt have a relatively large gape compared to their body size (Swanson et al. 2003), and are capable of consuming a high proportion of small fishes compared to similarly sized native species (Hrabik et al. 1998). The large gape of the non-native rainbow smelt was found to be significantly larger with respect to body depth and mass when compared to native fish species such as cisco (Coregonus artedi), spottail shiner (Notropus hudsonius), troutperch (Percopsis omiscomaycus), pumpkinseed (Lepomis gibbosus), yellow perch (Perca

3 flavascens), and walleye (Sander vitreus) (Swanson et al. 2003) which allows them to consume the relatively high proportion of fishes, thus elevating their trophic position when compared to similarly sized native forage fish (Coregonids) (Swanson et al. 2003). Some studies have found more specific dietary regimes for smelts. One study found that smelt in lakes containing at least one species of pelagic forage fish but lack Mysis (Class 2) have been found to feed primarily on zooplankton (42%), and larval fish (36%) (Vander Zanden and Rasmussen 1996). The same study also found that rainbow smelt that live in lakes that contain both Mysis and at least one species of pelagic forage fish (Class 3) tend to feed primarily on Mysis (32%) and larval fish (30%) (Vander Zanden and Rasmussen 1996). The preference for Mysis and forage fish compared to other Coregonids can lead to a higher level of bioaccumulation of contaminants such as mercury (Hg) and polychloropbiphenyls (PCB s) (Vander Zanden and Rasmussen 1996). Growth/Reproduction Rainbow smelt can grow up to a length of 35 cm (Hubbs and Lagler), although common sizes are cm ( ) in length, weighing approximately g (1/4-1/6 pound) (Werner). In most of Ontario, spawning takes place during the ice breakup. The smelts move up to 300 m upstream at night to spawn. During these spawning runs females can release up to 50,000 eggs, which are fertilized by males waiting downstream (Werner). Smelt begin to mature during the second year of life when 40.7 % of males and 17.7 % of females begin to mature and all smelts older than 2 years of age are usually sexually mature (Bailey 1964). Distribution The most current collated detailed distribution of rainbow smelt can be seen in Mandrak and Crossman (1992), however there are currently efforts underway to provide a more current detailed distribution for rainbow smelt. A more current distribution map

4 will allow for a comparison to the historical distribution and will allow for a better understanding of the current status of rainbow smelt in Ontario s inland waters. Rainbow smelt are found in both freshwater and marine environments and are native to coastal regions of North America, as well as in some landlocked freshwater populations. Rainbow smelt are primarily an anadromous fish species that usually live most of their life at sea and move to inland freshwater streams and rivers to spawn. They can however live entirely in freshwater and there are native landlocked freshwater populations that were established during the retreat of the glaciers during the last ice age (Mandrak and Crossman 1992, Mercado-Silva et al. 2006). The indigenous landlocked populations were originally only identified in Dore, Golden, Muskrat, and possibly Timiskaming Lakes (Evans and Loftus 1987) but have since become invasive and spread primarily through introductions by humans. Landlocked populations live primarily in lakes and move into smaller tributaries to spawn. Smelt are native in Lake Champlain, the St. Lawrence River, and most of the Lake Ontario drainage basin, but are not native to most inland lakes. It has also been introduced into most of the Great Lakes where it is now commonly found (Mandrak and Crossman 1992). Rainbow smelt were until recently limited to Lake Ontario, the St. Lawrence River, and lower Ottawa River watersheds (Mandrak and Crossman 1992) however, their spread has been facilitated by both intentional and accidental introductions in Ontario s waterways and lakes. Rainbow smelt were first introduced into St. Mary s River in 1909 and then Crystal Lake in Michigan in 1912 (Mandrak and Crossman 1992). Unfortunately, in some cases where both the rainbow smelt and the intended predator (Atlantic salmon, Salmo salar) were introduced in Crystal Lake in Michigan in 1912, the introduced Atlantic salmon did not persist but rainbow smelt flourished (Crossman 1990). Rainbow smelt then began to spread rapidly throughout the Great Lakes during the 1920s (Evans and Loftus 1987). It is thought that the introduction of rainbow smelt by humans is the primary method of invasion and the movement through connected waterways is the secondary method of invasion (Mandrak and Crossman 1992, Evans and Loftus 1987).

5 Many accidental introductions are thought to occur through the accidental or intentional dumping of bait buckets into lakes and connected waterways (Evans and Loftus 1987). Recent unintentional introductions have facilitated the spread of smelt to the Rainy, English, Winnipeg, and Nelson waterways of Manitoba and northwestern Ontario (Swanson et al. 2003). Although it is a native species in some areas of Ontario, rainbow smelt can cause some significant problems when introduced to areas where they did not exist before. It is thought that smelt gametes are spread through the accidental fertilization of eggs. Smelt are often caught during spawning runs when they are sexually active. When the fish are cleaned, the eggs can be artificially fertilized and the remains are often discarded in waterways other than where the fish were originally caught. It is thought that these artificially transported and fertilized eggs survive and hatch, with these populations becoming established in the destination water bodies (Evans and Loftus 1987). Predation/Competition with Native Species Rainbow smelt can impact other fish directly by predation on young fishes and indirectly through competition with native fishes for food. They further alter food web structure by becoming an alternate or primary prey source for piscivorous species (Evans and Loftus 1987). The co-occurrence of rainbow smelt and yellow perch has shown to have a significant and progressive impact on the decline of condition in yellow perch (Hrabik et al. 1998). Rainbow smelt and yellow perch have similar habitat characteristics and feed on similar species. Competition for these similar prey items in the same range has lead to the reduced condition of yellow perch in some lakes where these species coexist (Hrabik et al. 1998). In Crystal Lake in Wisconsin, it was found that juvenile perch have a warmer thermal preference (23 o C) in the shallow epilimnion and littoral zone when compared to the adult perch and rainbow smelt that prefer the cooler temperatures of the hypolimnion ( o C) (Hrabik et al. 1998, Scott and Crossman 1973). This thermal

6 preference is thought to exclude the juvenile perch from the adult rainbow smelt, which has prevented the direct impact of predation of smelt on juvenile perch (Hrabik et al. 1998). Interestingly, rainbow smelt can become a food source themselves for large yellow perch (as well as lake trout Salvelinus namaycush) at least in Lake Simcoe (Crossman 1990). Rainbow smelt have also been shown to have an impact on cisco (Coregonus artedi) through predation. One study showed that rainbow smelt did not impact cisco feeding success and therefore did not have an impact through competition but did force young cisco to colder zones through predation. This spatial forcing is thought to have caused recruitment failure in the young cisco (Hrabik et al. 1998). The results of some studies indicate that rainbow smelt are responsible for the extirpation of cisco from some lakes (in Sparkling Lake 1990) (Hrabik et al. 1998) Invasion by rainbow smelt in the Great Lakes also possibly had a role in the extinction of blue pike (Stizostedion vitreum glaucum) (Crossman 1990) although the role played by rainbow smelt cannot be determined equivocally. Rainbow smelt have also had a negative impact on lake whitefish (Coregonus clupeaformis) after the invasion of Lake Simcoe (Crossman 1990). Toxin accumulation A study conducted by Vander Zanden and Rasmussen (1996) showed that trophic position is a better indicator for PCB accumulation in fish species compared to discrete trophic levels. The researchers also found that rainbow smelt have a relatively higher trophic position when compared to most other Coregonid spp. The researchers therefore decided to analyze the data by separating smelt from the other Coregonid spp. The researchers found that in lakes containing lake trout and rainbow smelt, lake trout had an elevated trophic position. Furthermore, the researchers found that lakes containing lake trout and rainbow smelt where smelt were foraging primarily on Mysis and forage fish, lake trout had a significantly higher trophic position than lakes where smelt foraged primarily on zooplankton and forage fish (Vander Zanden and Rasmussen 1996).

7 Concurrently, the researchers also found elevated mean mercury (Hg) levels in lake trout where smelt were present (Vander Zanden and Rasmussen 1996). They found that in Class 2 lakes the average elevated Hg levels in lake trout were between / mg/kg and / mg/kg. They found that in Class 3 lakes, smelt presence coincided with a mean increase of 0.64+/ mg/kg to / mg/kg in lake trout (Vander Zanden and Rasmussen 1996). These results clearly demonstrate that lakes containing smelt show increased levels of Hg in lake trout. Some studies have shown that water bodies that have been invaded by rainbow smelt, have resulted in recruitment failures for walleye (Sander vitreus) which is thought to occur through either competition or predation with young of the year (YOY) walleye (Mercado-Silva et al. 2007). Other studies have shown that smelt introductions have resulted in the extirpation of native species such as perch (Perca flavescens) and cisco (Coregonus artedi) (Mercado-Silva et al. 2007). Thiaminase Rainbow smelt (as well as alewife) posess an enzyme in their bodies called thiaminase that breaks down thiamine (Vitamin B1), an essential vitamin for proper development of salmonids. Some researchers believe that when adult salmonids prey on large numbers of rainbow smelt, they can accumulate high levels of thiaminase in their bodies, which has been shown to cause complete reproductive failure of spawning salmon in the wild as well as high rates of fry mortality spawned by these fishes (Elrod et al. 1995, Fisher et al. 1996, Riley and Evans 2008). Some have even suggested that the introduction of forage fishes that contain this enzyme such as rainbow smelt and alewife might have played a significant contributing role in the extirpation of wild Atlantic salmon in Lake Ontario and other inland waters (Ketola et al. 2000). Evans and Loftus concluded in 1987 that there was no solid evidence that smelt predation has an impact on natural reproduction of lake trout, but they have implicated rainbow smelt in the recruitment failures of lake whitefish (Coregonus cluspeaformis) and cisco (Coregonus artedi).

8 Some authors have suggested that the thiamine deficiencies may be the result of multiple factors that all contribute to the overall decline in thiamine in salmonids, which in turn could result in the impact on reproductive success (Fitzsimons, Vandenbyllaardt, and Brown 2001). Water Bodies Vulnerable to Invasion Some studies that have used environmental variables to predict lakes that are vulnerable to smelt invasion have predicted that as many as 54% of Ontario s 8236 lakes are vulnerable. To put this in the proper context, the study found that only 3% of vulnerable lakes in Ontario are currently saturated with smelt (Mercado-Silva et al. 2006). The authors further examined the data to determine how many species that are sensitive to smelt invasion are contained within the lakes prone to invasion. They found that 94% of the lakes that are vulnerable to invasion contain at least one native species known to be negatively impacted by rainbow smelt (Mercado-Silva et al. 2006). The authors did however state that the model had a relatively high misclassification rate when the model was applied to Ontario, compared to the relatively lower misclassification rate when the model was applied to Wisconsin and Maine. The authors explain that this is due to the large number of lakes in Ontario (8236) where smelt were predicted to occur but have not been recorded at present (Mercado-Silva et al. 2006), however the experimenters were using the best information on the current distribution available to them, which has substantially fewer occurrences in Ontario (126) compared to the data set recently compiled for the Ontario Federation of Anglers and Hunters (OFAH) (~200 occurrences). The model had a relatively low specificity of 45% (ability of the model to correctly predict smelt presence), but had a high sensitivity of 87.3% (ability of the model to correctly predict smelt absence). Approximately 2 percent of the lakes in Ontario have currently been identified as having rainbow smelt (126/8236 lakes), and more than half of the lakes in Ontario have been identified as vulnerable to invasion (Mercado-Silva 2006). Evans and Loftus (1987) noted that ph, minimum lake depth, and surface area were the most significant variables limiting smelt distribution. Mercado-Silva et al. (2006) have developed a model based on

9 these parameters as well as secchi depth and shoreline perimeter. The experimenters found that the most important variable for lakes vulnerable to smelt invasion were maximum lake depth (score=100). The next closest variables were secchi depth and lake area with scores of and respectively (Mercado-Silva et al. 2006). The experimenters found that shoreline length and ph were of lesser importance to the predictive success of the model (Mercado-Silva et al. 2006). A detailed description of the parameters used can be found in Mercado-Silva et al. (2006).

10 References Bailey, M.M., Age, Growth, Maturity, and Sex Composition of the American Smelt, Osmerus mordax (Mitchill), of Western Lake Superior. Trans. Am. Fish. Soc. 93: Burbidge, R.G Age, Growth, Length-Weight Relationship, Sex Ratio, and Food Habits of American Smelt, Osmerus mordax (Mitchill), from Gull Lake, Michigan. Trans. Am. Fish. Soc. 98: Crossman, E.J Introduced freshwater fishes: A review of the North American perspective with emphasis on Canada. Can. J. Fish. Aquat. Sci. 48 (Suppl. 1): Elrod J.H., R. O Gorman, C.P. Schneider, T.H. Eckert, T. Schaner, J.N. Bowlby, and L.P. Schleen Lake trout rehabilitation in Lake Ontario. J. Gr. Lakes Res. 21(Suppl. 1): Evans, D.O., and D.H. Loftus Colonization of inland lakes in the Great Lakes region by rainbow smelt, Osmerus mordax: Their freshwater niche and effects on indigenous fishes. Can. J. Fish. Aquat. Sci. 44(Suppl. 2): Fisher, J.P., J.D. Fitzsimons, G.F. Combs Jr., and J.M. Spitsbergen Naturally occurring thiamine deficiency causing reproductive failure in Finger Lakes Atlantic salmon and Great Lakes lake trout. Trans. Am. Fish. Soc. 125: Fitzsimons, J.D., L. Vandenbyllaardt, and S.B. Brown The use of thiamine and thiamine antagonists to investigate the etiology of early mortality syndrome in lake trout (Salvelinus namaycush). Aquatic Toxicology 52: Hrabik, T.R., J.J. Magnuson, and A.S. McLain Predicting the effects of rainbow smelt on native fishes in small lakes: evidence from long-term research on two lakes. Can. J. Fish. Aquat. Sci. 55: Hubbs, C.L., and K.F. Lagler Fishes of the Great Lakes region. Revised edition. (Revised by G.R. Smith 2007). The University of Michigan Press. Ketola, G.H., P.R. Bowser, G.A. Wooster, L.R. Wedge, and S.S. Hurst Effects of Thiamine on reproduction of Atlantic salmon and a new hypothesis for their extirpation in Lake Ontario. Litvak, M.K., N.E. Mandrak Ecology of freshwater baitfish use in Canada and the United States. Fisheries 18: Mercado-Silva, N., J.D. Olden, J.T. Maxted, T.R. Hrabik, and M.J. Vander Zanden Forecasting the spread of invasive rainbow smelt in the Laurentian Great Lakes region of North America. Conservation Biology 20:

11 Mandrak, N.E., and E.J. Crossman, Postglacial dispersal of freshwater fishes in Ontario. Can. J. Zool. 70: Riley, S.C., and A.N. Evans, Phylogenetic and ecological characteristics associated with thiaminase activity in Laurentian Great Lakes fishes. Transactions of the American Fisheries Society 137: Scott, W.B., and E.J. Crossman, Freshwater fishes of Canada. Bull. Fish. Res. Board Can. 184: Vander Zanden, M.J., and J.B. Rasmussen, A trophic position model of pelagic foodwebs: Impact on contaminant bioaccumulation in lake trout. Ecological Monographs 66: Werner, R.G., Freshwater fishes of the northeastern United States: a field guide. Syracuse University Press.

12 A synthesis of the current literature on the distribution, life history, and impacts associated with invasive rainbow smelt (Osmerus mordax) Andrew Chard Trent University

13 Andrew Chard ERSC 316H Rainbow Smelt (Osmerus mordax) Factsheet What is Rainbow Smelt? Rainbow smelt are an anadromous fish species, which means that they usually live most of their life at sea but move to inland freshwater streams to spawn. They can however live entirely in freshwater and there are native landlocked freshwater populations. The indigenous landlocked populations were originally only identified in Dore, Golden, Muskrat, and possibly Timiskaming Lakes (Evans and Loftus 1987) but have since become invasive and spread primarily through introductions by humans. Landlocked populations live primarily in lakes and move into smaller tributaries to spawn. Rainbow smelt can grow up to a length of 35 cm (Hubbs and Lagler), although common sizes are cm ( ) and weigh approximately g (1/4-1/6 pound) (Werner). In most of Ontario, spawning takes place during the ice breakup. The smelts move up to 300 m upstream at night to spawn. During these spawning runs females can release up to eggs which are fertilized by males waiting downstream (Werner). Where is it found? Rainbow smelt are found in both freshwater and marine environments. Rainbow smelt were originally limited to Lake Ontario, St. Lawrence River, and lower Ottawa River watersheds (Mandrak and Crossman 1992) however, their spread has been facilitated by both intentional and accidental introductions. It is thought that the introduction of rainbow smelt by humans is the primary method of invasion and the movement through connected waterways is the secondary method of invasion (Mandrak and Crossman 1992, Evans and Loftus 1987). Smelt is native in Lake Champlain, the St. Lawrence River, and most of the Lake Ontario drainage basin it is not native to most inland lakes. It has also been introduced into most of the Great Lakes where it is now commonly found (Evans and Loftus 1987).

14 Andrew Chard ERSC 316H What does it eat? Rainbow smelt feeds mainly on zooplankton, but also feed on small fish species and the fry of some sportfish species. Rainbow smelt have been shown to have higher concentrations of toxins in their bodies because smelt are more piscivorous, feeding at a higher trophic position, than native forage fish (Evans and Loftus 1987; Franzin and others 1994; Vander Zanden and Rasmussen1996). What are the impacts? Rainbow smelt can impact other fish directly by predation on young fishes and indirectly through competition with native fishes for food. They can also alter food web structure by becoming an alternate or primary prey source for piscivorous species (Evans and Loftus 1987). Some studies have shown that water bodies that have been invaded by rainbow smelt, have resulted in failures for walleye (Sander vitreus) which is thought to occur through either competition or predation with young of the year (YOY) walleye (Mercado-Silva et al. 2007). Other studies have shown that smelt introductions have resulted in the extirpation of native species such as perch (Perca flavescens) and cisco (Coregonus artedi) (Hrabik et al. 1998). Rainbow smelt (as well as alewife) posess an enzyme in their bodies called thiaminase that breaks down thiamine (Vitamin B1), an essential vitamin for proper development of salmonids. It is thought that adult salmonids that prey on large numbers of rainbow smelt accumulate high levels of this enzyme in their bodies, which has shown to cause complete reproductive failure of spawning salmon in the wild as well as high rates of fry mortality spawned by these fishes (Elrod et al. 1995, Fisher et al. 1996). Some have even suggested that the introduction of forage fishes that contain this enzyme (alewife) were a significant contributor to the extirpation of wild Atlantic salmon in Lake Ontario and other inland waters (Ketola et al. 2000).

15 Andrew Chard ERSC 316H How is it Spread? Although it is native species in some areas of Ontario, rainbow smelts can cause some significant problems when introduced to areas where they did not exist before. It is thought that smelt are spread accidentally through the accidental fertilization of eggs. Smelt are often caught during spawning runs when they are sexually active. When the fish are cleaned, the eggs can be artificially fertilized and the remains are often discarded in waterways other than where the fish were originally caught where the invasive populations become established (Evans and Loftus 1987). Identification Rainbow smelt are long, slender, minnow-like fishes that can be distinguished by their large jaw, containing large teeth on the jaw, tongue and roof of the mouth. Rainbow smelt have an incomplete lateral line. They can also be distinguished from other similar fishes by the lack of barbells on the mouth, lack of pelvic spines or lack of spines in the dorsal fin. Rainbow smelt appear similar to brook silversides but can be distinguished by the presence of a single dorsal fin and small adipose fin compared to the brook silversides, which has two dorsal fins. Rainbow smelt also have a relatively short anal fin compared to the unusually long anal fin of brook silversides. Their colour is usually light green on the back with silvery sides and belly although their colour can darken in stained waters (Werner).