Tag Archives: InvArticle

Van Mierlo V.A., Green S.J., Emmerton C.A., Nasr M., Stuparyk, B.R., Vinebrooke, R.D., Buendia C., Wyatt F. and M. S. Poesch. (2026) Assessing changes in food web dynamics in freshwater ecosystems after the invasion of Northern Crayfish (F. virilis). Aquatic Invasions 21(1): 13-34..

Abstract: 

Aquatic invasive species are among the greatest threats to freshwater biodiversity. Crayfish are especially robust freshwater invaders that can compete on various trophic levels simultaneously. The Northern Crayfish (Faxonius virilis) was introduced to the North Saskatchewan River basin circa 1990. Their impact on Alberta’s native fish communities remains unknown. We sampled 10 North Saskatchewan River basin tributaries for F. virilis and six common native fishes. We used stable isotope analysis to investigate if there exists resource partitioning and/or competition between F. virilis and native fishes and whether F. virilis sympatry is related to differences in isotopic metrics/body condition of native fishes. Overlap (0.14–31.2%) of F. virilis and native species basin-wide isotopic niches indicated that F. virilis can potentially consume the same dietary resources as secondary consumer fishes. However, segregation of realized isotopic niches indicated no actual consumption of the same resources. Similarity in isotopic metrics/body condition of allopatric and sympatric native fish populations indicated that F. virilis sympatry did not have detectable negative trophic effects on native fishes. Thus, F. virilis may be using dietary plasticity to exploit a different trophic niche than native fishes, ergo, avoiding interspecific competition through resource partitioning.

Citation: Van Mierlo V.A., Green S.J., Emmerton C.A., Nasr M., Stuparyk, B.R., Vinebrooke, R.D., Buendia C., Wyatt F. and M. S. Poesch. (2026) Assessing changes in food web dynamics in freshwater ecosystems after the invasion of Northern Crayfish (F. virilis). Aquatic Invasions 21(1): 13-34.

Also Read:

Van Mierlo V. A.*, Green S. J., Emmerton C. A., Nasr M., Buendia C., Wyatt F. and M. S. Poesch. (2022). Occupancy of invasive Northern Crayfish (Faxonius virilis) in northern systems is driven primarily by tributary water temperature. Freshwater Science 41(4): 650-664.

*Lab members: Victoria Van Mierlo. Check out opportunities in the lab!

Edgar M., Kimmel, N. and M. S. Poesch. (2025) Community trophic structure within reservoirs change in the presence of invasive Chinese Mystery Snail (Cipangopaludina chinensis) and Northern Crayfish (Faxonius virilis). Aquatic Science 87: 99.

Abstract

The expansion of invasive species significantly threatens ecosystem biodiversity and stability, often leading to alterations in food web dynamics and trophic interactions. This study examines the impacts of two invasive species, the Chinese Mystery Snail (Cipangopaludina chinensis) and Northern Crayfish (Faxonius virilis), in Alberta’s reservoir ecosystems. These species, originally from Asia and Canada’s eastern regions respectively, have established populations in Alberta, raising concerns about their effects on local aquatic food webs. Using stable isotope analysis across five reservoirs with varying invasive species presence, we assessed shifts in trophic structure, resource use, and isotopic niche overlap among native and invasive species. Findings reveal that reservoirs with invasive species showed significant changes in food web length, trophic diversity, and isotopic niche overlap, especially in systems where both species coexisted. Notably, both invasive species reduced macrophyte availability, or availability of isotopically similar resources, leading to shifts in fish diets toward higher trophic levels and affecting their trophic positions. Additionally, niche overlap between the two invasives suggests potential competition for resources, with Northern Crayfish possibly predating on Chinese Mystery Snail in resource-scarce environments. These results indicate that invasive species presence can significantly impact trophic structures, leading to competitive exclusion, changes in fish feeding strategies, and broader ecosystem productivity alterations. Future management should prioritize containment and monitor these invasives’ long-term impacts, particularly given their potential to disrupt biodiversity and ecosystem function.

Citation: Edgar M.*, Kimmel, N. and M. S. Poesch. (2025) Community trophic structure within reservoirs change in the presence of invasive Chinese Mystery Snail (Cipangopaludina chinensis) and Northern Crayfish (Faxonius virilis). Aquatic Sciences 87: 99. DOI: 10.1007/s00027-025-01220-z.

Also Read:

Edgar M.*, Hanington P., Lu R., Proctor H., Zurawell R., Kimmel N. and M.S. Poesch (2022) The First Documented Occurrence and Life History Characteristics of the Chinese Mystery Snail (Cipangopaludina chinensis, Mollusca: Viviparidae) in Alberta, Canada. BioInvasions Records 11(2): 449-460.

*Lab members: Megan Edgar and Mark Poesch. Check out opportunities in the lab!

Fischer, S.M.*, Ramaza, P., Simmons, S., Poesch, M.S. and M.A. Lewis. (2023) Boosting propagule transport models with individual-specific data from mobile apps. Journal of Applied Ecology 60(5): 934-949.

Abstract:

Management of invasive species and pathogens requires information about the traffic of potential vectors. Such information is often taken from vector traffic models fitted to survey data. Here, user-specific data collected via mobile apps offer new opportunities to obtain more accurate estimates and to analyze how vectors’ individual preferences affect propagule flows. However, data voluntarily reported via apps may lack some trip records, adding a significant layer of uncertainty. We show how the benefits of app-based data can be exploited despite this drawback. Based on data collected via an angler app, we built a stochastic model for angler traffic in the Canadian province Alberta. There, anglers facilitate the spread of whirling disease, a parasite-induced fish disease. The model is temporally and spatially explicit and accounts for individual preferences and repeating behaviour of anglers, helping to address the problem of missing trip records. We obtained estimates of angler traffic between all subbasins in Alberta. The model’s accuracy exceeds that of direct empirical estimates even when fewer data were used to fit the model. The results indicate that anglers’ local preferences and their tendency to revisit previous destinations reduce the number of long inter-waterbody trips potentially dispersing whirling disease. According to our model, anglers revisit their previous destination in 64% of their trips, making these trips irrelevant for the spread of whirling disease. Furthermore, 54% of fishing trips end in individual-specific spatially contained areas with mean radius of 54.7km. Finally, although the fraction of trips that anglers report was unknown, we were able to estimate the total yearly number of fishing trips in Alberta, matching an independent empirical estimate.

Citation: Fischer, S.M., Ramaza, P., Simmons, S., Poesch, M.S. and M.A. Lewis. (2023) Boosting propagule transport models with individual-specific data from mobile apps. Journal of Applied Ecology 60(5): 934-949.

Also Read:

Poesch, M.S. and D.A. Jackson (2012) Impact of species-specific dispersal and regional stochasticity on estimates of population viability in stream metapopulations. Landscape Ecology 27: 405-416.

*Lab members: Samuel Fischer. Check out opportunities in the lab!

Van Mierlo V. A.*, Green S. J., Emmerton C. A., Nasr M., Buendia C., Wyatt F. and M. S. Poesch. (2022). Occupancy of invasive Northern Crayfish (Faxonius virilis) in northern systems is driven primarily by tributary water temperature. Freshwater Science 41(4): 650-664.

Abstract:

Invasive species are the 2nd-greatest threat to global freshwater biodiversity. Crayfish are especially robust invaders due to their omnivorous nature and ability to compete both directly (resource procurement) and indirectly (habitat occupation and modification) with native species. The Northern Crayfish (Faxonius virilis Hagen, 1870) was introduced to the North Saskatchewan River basin (Alberta, western Canada) and has persisted there since the early 1990s. Faxonius virilis’ impacts on native fish assemblages in the North Saskatchewan River have yet to be assessed, even though the watershed is ecologically, economically, and culturally valuable and home to multiple sensitive and at-risk fish species. We aimed to identify the instream environmental characteristics associated with F. virilis occupancy in the North Saskatchewan River basin and to determine which currently unoccupied tributaries are most vulnerable to F. virilis invasion. We used occupancy modeling to meet these objectives. We deployed 24-h baited crayfish traps and measured water temperature, turbidity, flow velocity, and physical complexity at 37 sites along the Alberta portion of the North Saskatchewan River basin. We detected F. virilis at 13/37 sites with no occurrences detected in the upper basin. Occupancy model selection and averaging revealed that water temperature alone was associated with occupancy of F. virilis in the North Saskatchewan River basin. Streams with mean summer water temperatures >∼19.7 C  were ≥50% more likely to be occupied by F. virilis than cooler streams and are at highest risk of invasion. Further, we found that streams with mean summer water temperatures <∼15.7 C had a <25% chance of becoming occupied by F. virilis than warmer streams. Coldwater streams may thus have some natural protection against F. virilis invasion. The results from this study provide practical guidelines for watershed management of invasive F. virilis populations in western Canadian river basins. Managing F. virilis is particularly important and time sensitive because F. virilis’ range will likely expand when water temperatures in the basin rise because of climate change.

Citation: Van Mierlo V.A., Green S.J., Emmerton C.A., Nasr M., Buendia C., Wyatt F. and M.S. Poesch. (2022). Occupancy of invasive Northern Crayfish (Faxonius virilis) in northern systems is driven primarily by tributary water temperature. Freshwater Science 41(4): 650-664.

Also Read:

Edgar M.*, Hanington P., Lu R., Proctor H., Zurawell R., Kimmel N. and M.S. Poesch (2022) The First Documented Occurrence and Life History Characteristics of the Chinese Mystery Snail (Cipangopaludina chinensis, Mollusca: Viviparidae) in Alberta, Canada. BioInvasions Records 11(2): 449-460.

*Lab members: Victoria Van Mierlo. Check out opportunities in the lab!

Edgar M.*, Hanington P., Lu R., Proctor H., Zurawell R., Kimmel N. and M.S. Poesch (2022) The First Documented Occurrence and Life History Characteristics of the Chinese Mystery Snail (Cipangopaludina chinensis, Mollusca: Viviparidae) in Alberta, Canada. BioInvasions Records 11(2): 449-460.

Abstract:

 The Chinese mystery snail Cipangopaludina fhinensis (Gray, 1834), a species native to Asia, is documented for the first time in Alberta, Canada, in McGregor Lake Reservoir in 2019. Here, we describe the initial finding of C. chinensis in Alberta, Canada, and biological information that may aid management efforts. Collected specimens were confirmed as C. chinensis through DNA barcoding. Analysis of growth rate, fecundity, and infection by digenean trematodes was assessed. It is unknown how C. chinensis arrived in Alberta. However, this species’ ability to withstand environmental stressors, such as desiccation, facilitates overland and long-distance transport via recreationists or deliberate release of C. chinensis into waterbodies. Snails collected from McGregor Lake Reservoir matched with GenBank results for C. chinensis from Korea. Analysis of digenean trematodes revealed that the population in McGregor Lake are not infected, as there were no cercariae present after 24 hours. Growth assessment over a period of 60 weeks revealed that shell length growth quickly outpaces growth in shell width. Upon emergence, C. chinensis are larger than many native snail species. The expansion of C. chinensis into Alberta poses potential negative consequences, such as decreased native snail biomass, increased nitrogen to phosphorus ratios, and additive impacts when paired with other invasive species.

Citation: Edgar M.*, Hanington P., Lu R., Proctor H., Zurawell R., Kimmel N. and M.S. Poesch (2022) The First Documented Occurrence and Life History Characteristics of the Chinese Mystery Snail (Cipangopaludina chinensis, Mollusca: Viviparidae) in Alberta, Canada. BioInvasions Records 11(2): 449-460. 

Also Read:

Van Mierlo V. A.*, Green S. J., Emmerton C. A., Nasr M., Buendia C., Wyatt F. and M. S. Poesch. (2022). Occupancy of invasive Northern Crayfish (Faxonius virilis) in northern systems is driven primarily by tributary water temperature. Freshwater Science 41(4).

*Lab members: Megan Edgar and Mark Poesch. Check out opportunities in the lab!

Firth, B., Poesch, M.S., Koops, M., Power, M. and D.A.R. Drake. (2021) Diet overlap of common and at-risk riverine benthic fishes before and after Round Goby (Neogobius melanostomus) invasion. Biological Invasions 23(1): 1-14.

Abstract:

Round Goby (Neogobius melanostomus) has invaded high diversity tributaries of the Laurentian Great Lakes, including those supporting multiple species of conservation concern. The extent and magnitude of ecological impacts on benthic riverine fishes is poorly understood, especially changes in dietary overlap and feeding strategy. We used a before-after study design to examine the impact of Round Goby on native benthic riverine fishes, including the Threatened Eastern Sand Darter (Ammocrypta pellucida) in the Sydenham River, Ontario, Canada. To evaluate shifts in diet overlap and feeding strategy, fishes were collected with multiple gears and the direct (diet overlap with the invader) and potential indirect (diet overlap among the native benthic fishes) impacts of Round Goby were assessed. Before the arrival of Round Goby, there were a total of 6 ecologically significant diet overlaps among the studied native benthic fishes. Following the arrival of Round Goby, there were 20 ecologically significant diet overlaps, with 6 out of 8 species, including Eastern Sand Darter, showing significant diet overlap with Round Goby. Fishes exhibiting significant dietary overlap with Round Goby shifted feeding strategies to become more specialized, a change in feeding consistent with potential competitive effects. Although the long-term consequences of invasion-induced dietary and feeding shifts remain poorly understood, increased competitive interactions suggested by dietary overlap may be occurring between Round Goby and native benthic riverine fishes and may exacerbate the observed declines of native species.

Citation: Firth, B., Poesch, M.S., Koops, M., Power, M. and D.A.R. Drake. (2021) Diet overlap of common and at-risk riverine benthic fishes before and after Round Goby (Neogobius melanostomus) invasion. Biological Invasions 23(1): 1-14. 

Also Read:

Poesch, M.S., Dextrase, A.J., Schwalb, A.N., and J. Ackerman (2010) Secondary invasion of the round goby into high diversity Great Lakes tributaries and species at risk hotspots: Potential new concerns for endangered freshwater species. Biological Invasions 12: 1269-1284.

Card, J.*, Hasler, C., Ruppert, J.*Donadt, C.* and M.S. Poesch. (2020) A three-pass electrofishing removal strategy is not effective for eradication of Prussian Carp in a North American stream network. Journal of Fish and Wildlife Management 11(2): 485-493.

Abstract:

Prussian Carp Carassius gibelio, also referred to as Gibel Carp, is a destructive aquatic invasive species, recently, found in Alberta Canada. Three-pass electrofishing is a potential approach to control some aquatic invasive fish species in stream habitats. The objectives of this study were to: 1) determine the efficacy of this strategy to control Prussian Carp in connected streams; and, 2) assess whether removal success was influenced by population size or the distance to the introduction site. We sampled sites using electrofishing in tributaries of the Red Deer River in both the summer and fall. Prussian Carp were detected at all sites prior to removal, with > 90 % probability of detection of this species within the first 120 m of electroshocking efforts. Overall, removal was deemed unsuccessful. We found that abundances of Prussian Carp were significantly higher post-removal. Removal success was significantly related to distance to the introduction site, suggesting that removal may be useful in targeted situations close to the edge of the invasion front. Additional removal and control strategies are needed by managers.

Citation: Card, J., Hasler, C., Ruppert, J., Donadt, C.* and M.S. Poesch. (2020) A three-pass electrofishing removal strategy is not effective for eradication of Prussian Carp in a North American stream network. Journal of Fish and Wildlife Management 11(2): 485-493. 

Highlighted in media: (link here)

Also Read:

Docherty, C.*, Ruppert, J.*, Rudolfsen, T.*, Hamann, A., and Poesch, M.S. (2017) Assessing the spread and potential impact of Prussian Carp (Carassius gibelio Bloch, 1782) to freshwater fishes in western North America. BioInvasions Records 6: 291-296.

*Lab members:  Jamie Card, Jonathan Ruppert, Caitlyn Donadt and  Mark Poesch. Check out opportunities in the lab!

Ruppert, J.L.W.*, Docherty,C.*, Rudolfsen, T.*, Neufeld, K.*, Hamilton, K.*, MacPherson, L. and M.S. Poesch. (2017) Native North American freshwater species get out of the way: Prussian Carp (Carassius gibelio) establishment impacts both fish and macroinvertebrate communities. Royal Society Open Science 4: 170400.

Abstract: 

Prussian carp (Carassius gibelio) are one of the most noxious non-native species in Eurasia. Recently, Prussian carp, a nonnative freshwater fish species, were genetically confirmed in Alberta, Canada and have been rapidly expanding their range in North America since establishment. Given their rapid range expansion, there is an increasing need to determine how Prussian carp may impact native species. We assessed the severity of the Prussian carp invasion by (i) determining their impact on fish communities, (ii) assessing their impact on benthic invertebrate communities, (iii) evaluating if Prussian carp alter abiotic conditions, and (iv) identifying where we find higher abundances of Prussian carp. When Prussian carp were established, we found significant changes to the fish community. Correspondingly, the degree of impact to benthic invertebrate communities was related to the stage of invasion (none, early or recent), where changes in fish communities were significantly concordant with changes in benthic invertebrate communities. Finally, we found that higher abundances of Prussian carp were significantly associated with lower abundances of a majority of native fish species. Altogether, using three lines of evidence, we determine that Prussian carp can have wide-ranging impacts on freshwater ecosystems in North America, pressing the need for management intervention.

Citation: Ruppert, J.L.W.*, Docherty,C.*, Rudolfsen, T.*, Neufeld, K.*, Hamilton, K.*, MacPherson, L. and M.S. Poesch. (2017) Native North American freshwater species get out of the way: Prussian Carp (Carassius gibelio) establishment impacts both fish and macroinvertebrate communities. Royal Society Open Science 4: 170400.

Also Read:

Docherty, C.*, Ruppert, J.*, Rudolfsen, T.*, Hamann, A., and Poesch, M.S. (2017) Assessing the spread and potential impact of Prussian Carp (Carassius gibelio Bloch, 1782) to freshwater fishes in western North America. BioInvasions Records 6: 291-296.

*Lab members: Jonathan Ruppert, Cassandra Docherty, Tyana Rudolfsen, Kenton Neufeld, Kyle Hamilton, Mark Poesch. Check out opportunities in the lab!

Docherty, C.*, Ruppert, J.*, Rudolfsen, T.*, Hamann, A., and Poesch, M.S. (2017) Assessing the spread and potential impact of Prussian Carp (Carassius gibelio Bloch, 1782) to freshwater fishes in western North America. BioInvasions Records 6: 291-296.

Abstract:

Prussian Carp (Carassius gibelio Bloch, 1782) is one of the most successful invasive species in Eurasia. Recently, Prussian Carp were genetically confirmed in Alberta, Canada, documenting the first detection of this species in North America. Given the close morphological similarity to their sister species, the Goldfish (Carassius auratus Linnaeus, 1758), it is likely that this species has been undetected for some time. We document the spread of Prussian Carp since arrival (circa 2000), and contribute a trait-based risk assessment to potential recipient communities in western North America. Using a meta-analysis of geo-referenced fisheries data in conjunction with original sampling in 2014, we show that the Prussian Carp range has increased by eight- to eleven-fold over 15 years in Alberta at a rate of approximately 233–1,250 km2 per year. Range expansions in the near future are possible through the Saskatchewan River drainage and south into the Missouri River basin, with easily accessible routes to Midwestern North America through irrigation canals. We show high life history trait overlap with other successful invasive species, such as Goldfish and Common Carp (Cyprinus carpio Linnaeus, 1758). Additionally, there was high life history trait overlap with several species of native sunfish (Centrarchidae) and suckers (Catostomidae). This study highlights Prussian Carp’s potential to widely impact North American freshwater ecosystems and to successfully compete with native taxa. Considered one of the worst invaders in Eurasia, the arrival of Prussian Carp in North America poses serious concern for fisheries managers. There is an urgent need to develop management plans before further range expansion and disruption of freshwater ecosystems by this new invasive species.

Citation: Docherty, C.*, Ruppert, J.*, Rudolfsen, T.*, Hamann, A., and Poesch, M.S. 2017. Assessing the spread and potential impact of Prussian Carp (Carassius gibelio Bloch, 1782) to freshwater fishes in western North America. BioInvasions Records 6: 291-296.

Spread of Prussian Carp in Alberta, Canada

Also Read:

Ruppert, J.L.W.*, Docherty,C.*, Rudolfsen, T.*, Neufeld, K.*, Hamilton, K.*, MacPherson, L. and M.S. Poesch. (2017) Native North American freshwater species get out of the way: Prussian Carp (Carassius gibelio) establishment impacts both fish and macroinvertebrate communities. Royal Society Open Science 4: 170400.

*Lab members: Cassandra Docherty, Jonathan Ruppert, Tyana Rudolfsen, Mark Poesch. Check out opportunities in the lab!

Poesch, M.S., Dextrase, A.J., Schwalb, A.N., and J. Ackerman (2010) Secondary invasion of the round goby into high diversity Great Lakes tributaries and species at risk hotspots: Potential new concerns for endangered freshwater species. Biological Invasions 12: 1269-1284.

Abstract:

The round goby (Neogobius melanostomus) first invaded North America in 1990 when it was discovered in the St. Clair River. Despite more than 15 years of potential invasion, many Great Lakes’ lotic systems remained uninvaded. Recently, we captured the round goby from several Great Lakes tributaries known as species-at-risk hotspots. With a combination of field sampling of round gobies and literature review of the impact of round gobies on native taxa, we assess the potential impacts of the secondary invasion to native species using three mechanisms: competition; predation; and indirect impacts from the loss of obligate mussel hosts. We estimate that 89% (17/19) of benthic fishes and 17% (6/36) of mussels that occur in these systems are either known or suspected to be impacted by the secondary invasion of round goby. In particular, we note that the distribution of potential impacts of round goby invasion was largely associated with species with a conservation designation, including seven endangered species (1 fish, 6 mussels). As these recent captures of round goby represent novel occurrences in high diversity watersheds, understanding the potential impacts of secondary invasion to native biota is fundamental to prevent species declines and to allow early mitigation.

Featured In: Fisheries 34(9): 421 (Link), & several media outlets.

Citation: Poesch, M.S., Dextrase, A.J., Schwalb, A.N., and Ackerman, J. 2010. Secondary invasion of the round goby into high diversity Great Lakes tributaries and species at risk hotspots: Potential new concerns for endangered freshwater species. Biological Invasions 12: 1269-1284. 

Also Read:

Edgar M.*, Hanington P., Lu R., Proctor H., Zurawell R., Kimmel N. and M.S. Poesch (2022) The First Documented Occurrence and Life History Characteristics of the Chinese Mystery Snail (Cipangopaludina chinensis, Mollusca: Viviparidae) in Alberta, Canada. BioInvasions Records 11(2): 449-460.