ArticlePDF Available

Rapid range extension of the Ponto-Caspian amphipod Dikerogammarus villosus in France: Potential consequences

DOI:10.1127/0003-9136/2004/0160-0057
Authors:
Loic Bollache at University Bourgogne Franche-Comté
Loic Bollache
Simon Devin at University of Lorraine
Simon Devin
Remi Wattier at University of Burgundy
Remi Wattier
M. Chovet
M. Chovet
M. Chovet
  • This person is not on ResearchGate, or hasn't claimed this research yet.
Show all 7 authorsHide
Download full-text PDF
Read full-text
Download citation

Abstract

Non-indigenous species are increasingly recognized as altering local communities in newly colonized areas. In some north European freshwater systems, the Ponto-Caspian invasive crustacean Dikerogammarus villosus (Amphipoda) is implicated to have such an effect, with general monitoring of its progress and general impact required. The present study contributes to this monitoring. D. villosus was observed in 2003 in all the major French rivers prospected (i.e. Rhine, Meuse, Moselle, Saône, Rhône, Seine, and Loire), a European region previously overlooked for its colonization. This species was also detected in some tributaries of the rivers Saône and Seine, and in Geneva Lake. The dynamics of this colonisation, inferred from samples made at different dates, show a rapid expansion westward, from its first appearance in the Saône in 1997. The colonised rivers are connected with the more important French harbours, which may facilitate future invasion of new countries. In two sites, D. villosus rapidly became the dominant crustacean species after its appearance. A comparison of the amphipod fauna between 2003 and ancient surveys also shows that some native species tend to disappear in the East of France. These data suggest an ongoing homogenisation process of amphipod assemblages.
Content uploaded by Thierry Rigaud
Author content
All content in this area was uploaded by Thierry Rigaud on Mar 05, 2014
Content may be subject to copyright.
Arch. Hydrobiol. 160 1 57–66 Stuttgart, May 2004
Rapid range extension of the Ponto-Caspian
amphipod Dikerogammarus villosus in France:
potential consequences
L. Bollache1*, S. Devin2, R. Wattier1, M. Chovet3, J.-N. Beisel2,
J.-C. Moreteau2and T. Rigaud1
With 2 figures and 1 table
Abstract: Non-indigenous species are increasingly recognized as altering local com-
munities in newly colonized areas. In some north European freshwater systems, the
Ponto-Caspian invasive crustacean Dikerogammarus villosus (Amphipoda) is im-
plicated to have such an effect, with general monitoring of its progress and general im-
pact required. The present study contributes to this monitoring. D. villosus was ob-
served in 2003 in all the major French rivers prospected (i. e. Rhine, Meuse, Moselle,
Saône, Rhône, Seine, and Loire), a European region previously overlooked for its co-
lonization. This species was also detected in some tributaries of the rivers Saône and
Seine, and in Geneva Lake. The dynamics of this colonisation, inferred from samples
made at different dates, show a rapid expansion westward, from its first appearance in
the Saône in 1997. The colonised rivers are connected with the more important French
harbours, which may facilitate future invasion of new countries. In two sites, D. villo-
sus rapidly became the dominant crustacean species after its appearance. A comparison
of the amphipod fauna between 2003 and ancient surveys also shows that some native
species tend to disappear in the East of France. These data suggest an ongoing homo-
genisation process of amphipod assemblages.
Key words: invasions, Dikerogammarus villosus, gammarids, French hydrosystem.
1Authors’ addresses: Equipe Ecologie Evolutive, UMR CNRS 5561 Biogéoscien-
ces, Université de Bourgogne, 6 boulevard Gabriel, 21000 Dijon, France.
2Equipe de Démoécologie, UR LBFE, Université de Metz, Campus Bridoux, avenue
du Général Delestraint, 57070 Metz, France.
3DIREN Centre, Service de l’eau et des milieux aquatiques, 5 avenue Buffon, BP
6407, 45064 Orléans Cedex 2, France.
* Author for correspondence; E-mail: loic.bollache@u-bourgogne.fr
DOI: 10.1127/0003-9136/2004/0160-0057 0003-9136/04/0160-0057 $ 2.50
2004 E. Schweizerbart’sche Verlagsbuchhandlung, D-70176 Stuttgart
... Its displacement of native species (MacNeil et al., 2011;MacNeil & Platvoet, 2013) also facilitates the establishment of other invasive alien species (Bollache et al., 2004;Leuven et al., 2009). Notably, it is the only invasive amphipod with documented monetary costs . ...
... Our study was therefore limited by our focus on rivers and streams. Dikerogammarus villosus also occurs in lentic freshwaters including lakes, ponds, and brackish waters, and has marked impacts on these ecosystems (Bacela-Spychalska et al., 2013;Bollache et al., 2004;Minchin et al., 2019). Its occurrence in other countries could also be underestimated, resulting in relatively few time series, for example the Netherlands or Switzerland (Altermatt et al., 2014;Bij de Vaate & Klink, 1995). ...
Tracking a killer shrimp: Dikerogammarus villosus invasion dynamics across Europe
Article
Full-text available
Aim Invasive alien species are a growing problem worldwide due to their ecological, economic and human health impacts. The “killer shrimp” Dikerogammarus villosus is a notorious invasive alien amphipod from the Ponto‐Caspian region that has invaded many fresh and brackish waters across Europe. Understandings of large‐scale population dynamics of highly impactful invaders such as D. villosus are lacking, inhibiting predictions of impact and efficient timing of management strategies. Hence, our aim was to assess trends and dynamics of D. villosus as well as its impacts in freshwater rivers and streams. Location Europe. Methods We analysed 96 European time series between 1994 and 2019 and identified trends in the relative abundance (i.e. dominance %) of D. villosus in invaded time series, as well as a set of site‐specific characteristics to identify drivers and determinants of population changes and invasion dynamics using meta‐regression modelling. We also looked at the spread over space and time to estimate the invasion speed (km/year) of D. villosus in Europe. We investigated the impact of D. villosus abundance on recipient community metrics (i.e. abundance, taxa richness, temporal turnover, Shannon diversity and Pielou evenness) using generalized linear models. Results Population trends varied across the time series. Nevertheless, community dominance of D. villosus increased over time across all time series. The frequency of occurrences (used as a proxy for invader spread) was well described by a Pareto distribution, whereby we estimated a lag phase (i.e. the time between introduction and spatial expansion) of approximately 28 years, followed by a gradual increase before new occurrences declined rapidly in the long term. D. villosus population change was associated with decreased taxa richness, community turnover and Shannon diversity. Main Conclusion Our results show that D. villosus is well‐established in European waters and its abundance significantly alters ecological communities. However, the multidecadal lag phase prior to observed spatial expansion suggests that initial introductions by D. villosus are cryptic, thus signalling the need for more effective early detection methods.
View
... The predatory behavior of the killer shrimp is generally recognized as a crucial determinant of its ecological impact on other benthic invertebrates, including native amphipods. A number of laboratory trials on the feeding preferences of the gammarid supports this assumption (Krisp and Maier 2005;Kinzler et al. 2008;Pellan et al. 2016;Taylor and Dunn 2017), together with indirect evidences from field investigations highlighting significant declines in native macroinvertebrate assemblages after D. villosus invasion (Muskó 1989;Bollache et al. 2004;Noordhuis et al. 2009). ...
... 2015). The species was found at high abundance in 2015 and 2016 (Mancinelli et al. 2018;2020); the extremely reduced occurrence recorded in 2018 at the same location (this study) coincides with the recent establishment of D. villosus and suggests that the latter may have played a negative impact on E. veneris abundance, as hypothesized for other native amphipods in other investigations (Muskó 1989;Bollache et al. 2004;Noordhuis et al. 2009). Besides representing an important food source for macroinvertebrates, fish, birds and amphibians, E. veneris also plays a major role in leaf detritus processing in lacustrine environments (Mancinelli et al. 2002(Mancinelli et al. , 2007. ...
Ontogenetic shift in the trophic role of the invasive killer shrimp Dikerogammarus villosus: a stable isotope study
Article
Full-text available
The introduction of the amphipod Dikerogammarus villosus in European fresh waters is to date recognized as a threat to the integrity of invaded communities. Predation by D. villosus on native benthic invertebrates is assumed as the key determinant of its ecological impact, yet available information describe the species as a primary consumer as well as a carnivore depending on local conditions. Here, we assessed the trophic position (TP) of D. villosus in Lake Trasimeno, a recently invaded lentic system in central Italy, using the CN isotopic signatures of individuals captured in winter spanning two orders of magnitude in body size. TP estimations were compared with those characterizing the native amphipod Echinogammarus veneris and other representative invertebrate predators. On average, D. villosus showed a trophic position higher than E. veneris , and comparable with that of odonate nymphs. An in-depth analysis revealed that large-sized individuals had a trophic position of 3.07, higher than odonates and close to that of the hirudinean predator Erpobdella octoculata , while small-sized specimens had a trophic position of 2.57, similar to that of E. veneris (2.41). These findings indicate that size-related ontogenetic shifts in dietary habits may per se vary the nature of the interaction between Dikerogammarus villosus and native invertebrates from competition to predation. Information collated from published isotopic studies corroborated the generality of our results. We conclude that intra-specific trophic flexibility may potentially amplify and make more multifaceted the impact of the species on other invertebrate species in invaded food webs.
View
... As a result of their high predation ability, the species composition and diversity of invaded waters can change substantially (Arbačiauskas & Gumuliauskaitė, 2007;Dick & Platvoet, 2000). The native gammarid species used in our investigation, G. jazdzewskii and G. pulex, are widely distributed across Central Europe (Pinkster, 1972;Rudolph et al., 2018), but their displacement by larger and more predatory invasive gammarids has been documented previously (Boets et al., 2010;Bollache, 2004;MacNeil et al., 2011). ...
New species, new story: The impact of invasive non-host predators on host-trematode interactions
Article
  • Jul 2023
1. Predation is considered one of the key drivers shaping the relationships between animals. There is increasing evidence that non-host aquatic taxa use free-living parasite stages as prey, including motile cercariae of digenean trematodes. However, species-specific predator differences in cercarial consumption are poorly understood, especially when invasive consumers are involved. 2. We used experimental approaches to investigate the possible predator-induced reduction in trematode-host encounters in freshwater benthic communities. Four gammarid species, two native European (Gammarus jazdzewskii and G. pulex) and two invasive Ponto-Caspian (Dikerogammarus villosus and Pontogammarus robust-oides), were selected as predators of echinostomatid cercariae (Echinoparyphium aconiatum). 3. We hypothesised that (i) all predators will prey on cercariae, but the amount of prey consumed will vary, the invaders will be more voracious than native species, and (ii) the effect of predator-induced dilution of cercariae will depend on the environmental condition, i.e., the presence of the natural target host (the planorbid snail Planorbarius corneus) and alternative food resource; the exposure of predators to these two basic environmental factors will reduce their consumption rates of cercariae. 4. The extent of the dilution effect caused by gammarids was highly predator species-dependent and also varied depending on experimental conditions. Overall, all gammarids preyed on cercariae and reduced infection levels in the target snail host, but the invaders were more efficient than the native species. Furthermore, decreased consumption rates of cercarial prey were observed in the presence of both the target snail hosts and alternative food resources, except for invasive P. robustoides consuming more cercariae when a snail host was present. 5. The observed differences among predators in the consumption of cercariae may be a result of complex interaction traits of parasites, predators and target hosts, such as different predatory behaviour of invasive and native amphipods, change in parasite behaviour in response to the presence/chemical signals of the target host and a predator-induced “ecology of fear” interfering with the dilution effect of parasites. 6. We provided evidence that gammarids can cause a significant reduction in parasite- host encounters. The high consumption rates, especially in the presence of easily available alternative food resources, emphasise the importance of free- living cercariae as an energy resource in aquatic food webs. The observed preda-tor differences in the consumption of cercariae are further evidence of the higher competitive ability of invasive species. Simultaneously, our results indicate that the appearance of new predators in the environment may interfere with estab-lished host- parasite interactions.
View
... However in the Gulf of Gdasnk, round gobies were found to migrate up to 40 km upstream in the Vistula River (Corkum et al. 2004). The secondary movements between sites has potentially been facilitated by abandoned eggs in nests deposited in crevices on ships on freight vessels dispersed by ships moving from port to port (Ray & Corkum 2001 Germany (Nesemann et al. 1995), France (Devin et al. 2004), Italy (Casellato et al. 2006), Belarus ) Poland (Grabowski et al. 2007) Ireland and England (Defra 2011 However, D. villosus is considered likely to continue to disperse in Great Britain, facilitated by its broad environmental tolerances, its climatic suitability to broad areas of GB, and the extensive connectivity, both natural and artificial, of the hydrological network (Gallardo et al. 2011). ...
Review of invasion pathways and provisional pathway management plan for non-native Ponto-Caspian species of potential invasion risk to Great Britain
Technical Report
Full-text available
  • Mar 2012
The potential (and in some cases actual) impact that each species would have in GB were also reviewed. • The list consisted of two species of molluscs, three fish, eight crustacea and one cnidaria of which five are recognised as currently being present in GB waters. • A literature review conducted on each of the species identified pathways and mechanisms of introduction and translocation most commonly associated with the species. • From this shipping was recognised as the most common pathway of introduction into GB, with ballast water being the most common mechanism and then (in descending order) inland boating (a secondary pathway of dispersal), hull fouling (a mechanism of the shipping pathway), unintentional stocking (secondary pathway), anglers gear (secondary pathway), air/land transport (primary pathways) and intentional release (secondary pathway). • The most common forms of dispersal (secondary pathway) were identified as natural dispersal and recreational activities (e.g. anglers, recreational boats and canoes), other secondary pathways identified were the ornamental trade, unintentional stocking and incidental transport. • The main drivers behind the predominant mechanisms/pathways were global trade/economic growth and recreation. • Species identified as being associated with more pathways and mechanisms are thus more likely to gain entry into GB and/or disperse within GB once introduced. It is therefore possible to rank the spread in order of 'threat' posed. • An outline of a provisional Pathway Management Action Plan (PAP) is provided outlining: o Stakeholders that should be involved in the further development of the PAP o Target areas of development to prevent further introductions o Actions to aid in preventing further spread o Recommendations on the development of biosecurity, control and/or eradication plans o The development of contingency plans for rapid response 3
View
... Thus, to the extent of our knowledge, there are no high-resolution, up to date, modern distribution maps comprising the global ranges of APCAs. This is surprising given that numerous studies have provided such data at a regional scale (Jażdżewski and Konopacka 1988;Bollache et al. 2004;Grudule et al. 2007;Žganec et al. 2009;Arbačiauskas et al. 2011;Borza 2011;Borza et al. 2015;Meßner and Zettler 2018), and range expansions are routinely reported (Copilaș-Ciocianu and Arbačiauskas 2018; Moedt and Van Haaren 2018;Minchin et al. 2019;Lipinskaya et al. 2021;Copilaș-Ciocianu and Šidagyė-Copilas 2022). Even though the spatio-temporal dispersal patterns are relatively well known for many species (Bij de Vaate et al. 2002;Grigorovich et al. 2002;Cristescu et al. 2004;Rewicz et al. 2015;Jażdżewska et al. 2020), a lack of high resolution distribution data precludes efficient global monitoring and hampers predictions of future invasion pathways. ...
Global distribution and diversity of alien Ponto-Caspian amphipods
Article
Full-text available
The Ponto-Caspian region is an important donor of aquatic alien species throughout the Northern Hemisphere, many of which are amphipod crustaceans. Despite decades of ongoing spread and negative effects on native biota, a complete picture of the global diversity and distribution of these amphipods has yet to emerge, hampering efficient monitoring and predictions of future invasion pathways. Herein, we provide a comprehensive summary of alien species taxonomic and ecomorphological diversity, as well as high-resolution distribution maps and biogeographical patterns based on > 8000 global records. We find that up to 39 species in 19 genera and five families, belonging to all four currently recognized ecomorphs, are potentially alien, their diversity gradually decreasing with distance from the native region. Most species (62%) have limited distributions, 15% are widespread, and 23% exhibit intermediate ranges. We also find that regions adjacent to the native range are comparatively less well-sampled than more distant regions. Biogeographical clustering revealed three faunal provinces that largely correspond with the Southern, Central and Northern invasion corridors. We conclude that (1) alien amphipods are a representative subsample of the native Ponto-Caspian phylogenetic and ecomorphological diversity, and (2) that their biogeographical patterns are driven by anthropogenic factors acting on taxonomically distinct native regional species pools.
View
... Six recorded species can be considered invasive due to their presence in high densities and their widespread distribution along the Sava and Drava Rivers. At most sites with invasive species, there were no native species or they were present only in low densities, as observed in studies of large rivers in France and Poland (Bollache et al., 2004;Grabowski et al., 2007a). In the Sava and Drava Rivers, invasive peracarids have been spreading upstream. ...
Contribution of alien peracarid crustaceans to the biocontamination of benthic macroinvertebrate assemblages in Croatian large rivers
Article
Full-text available
  • Mar 2022
Contribution of alien peracarid crustaceans to the biocontamination of benthic macroinvertebrate assemblages in Croatian large rivers Peracarid crustaceans (orders Amphipoda, Isopoda and Mysida) are one of the most important groups of invaders in fresh and brackish waters. Although large rivers in Croatia have been heavily invaded by peracarid crustaceans, little is known about their impact on local benthic macroinvertebrate assemblages. The main aim of this study was to investigate the contribution of alien Peracarida to the biocontamination of macroinvertebrate assemblages in Croatian large rivers as a proxy measure of their impact. Quantitative sampling was conducted twice (2015 and 2016/2017), at 48 sites on four large rivers (Danube-4, Sava-21, Drava-20, Mura-3). Physicochemical parameters were measured eight times during 2015 and 2016. In total, 16 species were recorded, five native and 11 alien species. The highest number (10 alien species, most from genus Dikerogammarus and Chelicorophium) were found in the Danube River, while subsets of alien species were found in the Sava (5 spp.) and Drava Rivers (6 spp.), and no alien species were found in the Mura River. The most upstream reaches of the Mura, Drava, and Sava Rivers in Croatia have not yet been colonized by invasive peracarids and the native peracarids are still abundant there. In the Drava River, alien Peracarida had the highest densities. Significant negative correlations were established between the number of native taxa and alien Peracarida species. Proportions of alien peracarids in the total density of benthic macroinvertebrates were spatially variable, the highest average values in the Drava River (24.4 %), and lower in the Danube (20 %) and the Sava (17.7 %) Rivers. Alien Peracarida had the most important contribution to the richness and abundance contamination of macro-invertebrate assemblages. The upstream spread of invasive peracarids will increase biocontamination and could cause a decline of native species richness and abundance in the most upstream reaches of the Sava and Drava Rivers. To prevent further upstream spread of alien Peracarida, "check, clean and dry" protocols should be included in the national regulations.
View
... They are widespread across Europe and co-occur in many places, sharing similar habitat preferences and life history traits (Grabowski et al. 2007;Bovy et al. 2015;Clinton et al. 2018). Usually D. villosus dominates and displaces D. haemobaphes (Kley and Mayer 2003;Bollache et al. 2004;Gruszka and Woźniczka 2008;Kinzler et al. 2009;Žganec et al. 2009;Bącela-Spychalska et al. 2012), though opposite situations have also been reported from the UK, where D. haemobaphes is more widely distributed (Clinton et al. 2018). ...
What doesn't kill you doesn't make you stronger: Parasites modify interference competition between two invasive amphipods
Article
Full-text available
  • Oct 2021
We used a freshwater amphipod-microsporidian model (Ponto-Caspian hosts: Dikerogammarus villosus and D. haemobaphes, parasite: Cucumispora dikerogammari) to check whether parasites affect biological invasions by modulating behaviour and intra-and interspecific interactions between the invaders. We tested competition for shelter in conspecific and heterospecific male pairs (one or both individuals infected or non-infected). In general, amphipods of both species increased their shelter occupancy time when accompanied by infected rather than non-infected conspecifics and heterospecifics. Infected am-phipods faced lower aggression from non-infected conspecifics. Moreover, D. villosus was more aggressive than D. haemobaphes and more aggressive towards conspecifics vs. heterospecifics. In summary, infection reduced the intra-and interspecific competitivity of amphipods, which became less capable of defending their shelters, despite their unchanged need for shelter occupancy. Dikerogammarus haemobaphes, commonly considered as a weaker competitor, displaced by D. villosus from co-occupied locations, was able to compete efficiently for the shelter with D. villosus when microsporidian infections appeared on the scene. This suggests that parasites may be important mediators of biological invasions, facilitating the existence of large intra-and interspecific assemblages of invasive alien amphipods.
View
... This situation lead to a deterioration which results from punctual and diffuse pollution, the modification of the physical and chemical characteristics, and the exploitation of cultivable land surfaces due to the intensification agricultural activities and rampant urbanization [1]. They thus negatively influence not only the ecological quality of the hydro-system, but also biological communities in general ( [1]; [2]). Anthropogenic actions therefore have negative consequences on the health of rivers. ...
Assessment of the ecological status of the rivers of the city of Douala from Macrophyte communities: Case of Kondi and Tongo Bassa
Article
Full-text available
  • May 2021
Observations made in rivers of Douala showed that aquatic ecosystems receive little attention in terms of their environmental monitoring. The aim of this study was to assess the ecological status of Kondi and Tongo Bassa rivers at from their communities of macrophytes. Specifically, it was question to evaluate the physicochemestry environment of these rivers as well as the diversity of the macrophyte species. Then, the physicochemestry parameters were measured (about 50cm deep) between 08am and 11am. Concerning characterization of macrophytes, 03 transects of 400m length each were materialized. Then, 201 quadrats of 1m2 were realised to make a specific and quantitative inventory. The listed species were assigned an Abundance-dominance coefficient. Then, the diversity and resemblance indices, the abundance index, the average recovery, the Shannon index and the Piélou equitability index, the Sorensen similarity coefficient, the Shannon index and the Piélou equitability index were analysed. According to results, ammonia, orthophosphates and nitrates particularly influence the distribution of macrophytes in the Kondi and the Tongo Bassa rivers. These parameters show that the water include high organic matter loads indicating organic pollution. In addition, the plant communities encountered in these rivers were relatively rich, diversify and distributed according to a decreasing gradation of mineralization and trophy. Also, the Piélou index in these rivers was generally below 0.55 reflecting poorly diversified waters. Finally, the structure of the macrophyte reveals that it was generally dominated by a few species, including the Poaceae particulary Pennisetum purpureum species, characteristic of eutrophic environments.
View
Dikerogammarus villosus (killer shrimp)
Article
  • Jan 2022
This datasheet on Dikerogammarus villosus covers Identity, Overview, Distribution, Dispersal, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.
View
Gammarus tigrinus
Article
  • Jan 2022
This datasheet on Gammarus tigrinus covers Identity, Overview, Distribution, Dispersal, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.
View
Predicting the identity and impact of future biological invaders: A priority for aquatic resource management
Article
Full-text available
The identification and risk assessment of potential biological invaders would provide valuable criteria for the allocation of resources toward the detection and control of invasion threats. Yet, freshwater biologists have made few attempts at predicting potential invaders, apparently because such efforts are perceived to be costly and futile. We describe some simple, low-cost empirical approaches that would facilitate prediction and demonstrate their use in identifying high-risk species from an important donor region: the Ponto-Caspian (Black, Caspian, and Azov seas) basin. This region is the source of several freshwater organism already invading North America, including the zebra mussel (Dreissena polymorpha), quagga mussel (Dreissena bugensis), ruffe (Gymnocephalus cernuus), and round goby (Neogoblus melanostomus). Based on a thorough literature review, we identify 17 additional Ponto-Caspian animals that have recent invasion histories and are likely to be transported overseas in ship ballast writer; moreover, their broad salinity tolerance could allow them to survive an incomplete ballast-water exchange. These results suggest that, unless current vectors are more effectively controlled, the Great Lakes - St. Lawrence River system and other North American inland waterways will continue to receive and be impacted by invasive Eurasian species.
View
Facilitative interactions among aquatic invaders: is an “invasional meltdown” occurring in the Great Lakes?
Article
Full-text available
  • Dec 2001
A widely cited hypothesis in ecology is that species-rich communities are less vulnerable to invasion than species-poor ones, owing to competition for limiting resources (the "biotic resistance" model). However, evidence for biotic resistance in aquatic ecosystems is equivocal. Contrary to the view that communities become more resistant to invasion as they accumulate species, the rate of invasion has increased over the past century in areas that have received frequent shipping traffic. Furthermore, introduced species may facilitate, rather than compete with, one another. A review of invasions in the Great Lakes indicates that direct positive (mutualistic and commensal) interactions among introduced species are more common than purely negative (competitive and amensal) interactions. In addition, many exploitative (e.g., predator-prey) interactions appear to be strongly asymmetric in benefiting one invading species at a negligible cost to another. These observations, combined with an increasing invasion rate in the Great Lakes, tentatively support the Simberloff - Von Holle "invasional meltdown" model. The model posits that ecosystems become more easily invaded as the cumulative number of species introductions increases, and that facilitative interactions can exacerbate the impact of invaders. It provides a theoretical argument for substantially reducing the rate of species introductions to the Great Lakes.
View
Preditory impact of the freshwater invader Dikerogammarus vilosus (Crustacea: Amphipoda)
Article
Full-text available
  • Jun 2002
To assess the increasing threats to aquatic ecosystems from invasive species, we need to elucidate the mechanisms of impacts of current and predicted future invaders. Dikerogammarus villosus, a Ponto-Caspian amphipod crustacean, is invading throughout Europe and predicted to invade the North American Great Lakes. European field studies show that populations of macroinvertebrates decline after D. villosus invasion. The mechanism of such impacts has not been addressed empirically; however, D. villosus is known to prey upon and replace other amphipods. Therefore, in this study, we used microcosm and mesocosm laboratory experiments, with both single and mixed prey species scenarios, to assess any predatory impact of D. villosus on a range of macroinvertebrate taxa, trophic groups, and body sizes. Dikerogammarus villosus predatory behaviour included shredding of prey and infliction of "bite" injuries on multiple victims. Dikerogammarus villosus killed significantly greater numbers of macroinvertebrates than did the native Gammarus duebeni, which is currently being replaced by D. villosus. This invader thus appears to impact on freshwater ecosystems through its exceptional predatory capabilities. We predict that future invasions by D. villosus will have serious direct and indirect effects on freshwaters, with its invasion facilitated in a larger "invasional meltdown" in regions like the North American Great Lakes.
View
Geographical patterns in range extension of Ponto-Caspian macroinvertebrate species in Europe
Article
Full-text available
Range extensions of aquatic Ponto-Caspian macroinvertebrate species in Europe have mainly been facilitated by the interconnection of river basins through man-made canals and intentional introductions. Three inland migration corridors can be distinguished: (i) a northern corridor: Volga → Lake Beloye → Lake Onega → Lake Ladoga → Neva → Baltic Sea, (ii) a central corridor connecting the rivers Dnieper → Vistula → Oder → Elbe → Rhine, and (iii) a southern corridor connecting the Danube and Rhine rivers. Important trade harbours in Europe were connected via these corridors allowing further range extensions of macroinvertebrate species attached to a vessel's hull or in ballast water. The central corridor was the main migration route before 1992, after which the southern corridor became the most important migration route for the range expansions to the west because of the reopening of the Main-Danube Canal, connecting the Rhine and Danube basins. Especially the water level maintenance in the upper part of the canal, with water supply from the Danube basin, facilitated migration of mobile animals (e.g., crustaceans) from the Danube basin towards the Rhine basin; however, contribution of other transport mechanisms (e.g., shipping) is expected in the near future.
View
Dikerogammarus villosus (Amphipoda : Gammaridae) : Another invasive species newly established in the Moselle River and French hydrosystems
Article
Full-text available
Based on field observations performed in 1999 and 2000, the exotic amphipod Dikerogammarus villosus is now well established throughout the navigable sector of the River Moselle in France. D. villosus co-occurs with Gammarus pulex, G. tigrinus and D. haemobaphes, another recent exotic species found in this tributary of the River Rhine. The maximal size of individuals of D. villosus collected (15.7 mm) is lower in the River Moselle than in other basins, where this species could reach up to 30 mm (Neseman et al. 1995). Nevertheless it represents the largest gammarids found in the French sector of the River Moselle. Other particular traits are its wide phenotypic plasticity, varying from a melanic to a striped form, and its predatory behavior. These particular traits may favour the establishment of this species on a recipient ecosystem. The occurrence of D. villosus was noted in the Alsace Canal and in the River Rhone, showing that its immigration across French hydrosystems is still in progress.
View
View
Recent mass invasion of the North American Great Lake by Ponto-Caspian species
Article
The North American Great Lakes have been invaded and dramatically altered by more than 145 alien species. Many invasions have occurred during the past few decades because of the release of Eurasian ballast water from transoceanic ships. Current regulations require ships to exchange foreign ballast with highly saline water before entering the Great Lakes; this procedure should prevent colonization by strictly freshwater species, but species with broad salinity tolerance might survive transport in exchanged water. A recent series of invasions by euryhaline organisms from the Black and Caspian Seas region signals a new phase in the transformation of the Great Lakes - one that supports the concept of an 'invasional meltdown'.
View
View
Asymmetry in mutual predation: Possible reason for the replacement of native gammarids by invasives
Article
Mutual predation among two invasive gammarids (Dikerogammarus villosus and Echinogammarus ischnus) and two natives (Gammarus fossarum and Gammarus roeseli) was studied in laboratory experiments. Both invasives were much stronger predators than the two natives. Between 56-86% of the replicates resulted in the death of natives when the invasive species were the predators, while only 10-18% resulted in the death of invasives in reverse combinations. Predation by invasives on natives generally exceeded cannibalism within species by a factor of 2 to 4. Both invasive species preyed less heavily on each other than on natives. The results suggest that the observed asymmetry in strength of mutual predation can be a key factor in the displacement of native gammarids by invasives in parts of Central European rivers and that low predation between invasives may permit their coexistence. Thus, the results of this study support the opinion that intraguild predation can be an important reason for species replacement in the field.
View
Homogenization of Freshwater Faunas
Article
Biotic homogenization is the increased similarity of biotas over time caused by the replacement of native species with nonindigenous species, usually as a result of introductions by humans. Homogenization is the outcome of three interacting processes: introductions of nonnative species, extirpation of native species, and habitat alterations that facilitate these two processes. A central aspect of the homogeniza-tion process is the ability of species to overcome natural biogeographic barriers either through intentional transport by humans or through colonization routes created by hu-man activities. Habitat homogenization through reservoir construction contributes to biotic homogenization as local riverine faunas are replaced with cosmopolitan lentic species. The homogenization process has generally increased biodiversity in most freshwater faunas, as the establishment of new species has outpaced the extinction of native species. There are important exceptions, however, where the establishment of nonindigenous species has had devastating impacts on endemic species. The ho-mogenization process appears likely to continue, although it could be slowed through reductions in the rate of invasions and extirpations and by rehabilitating aquatic habitats so as to favor native species.
View