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Martin Reichard - One of the best experts on this subject based on the ideXlab platform.
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The role of zebra Mussels on bitterling oviposition
2016Co-Authors: Veronika Bartáková, Martin ReichardAbstract:Non-native species can affect coevolved relationships. Bittering fish lay their eggs into live unionid Mussels. In experiments in laboratory, semi-natural and natural conditions, we examined: a) the effect of zebra Mussel (Dreissena polymorpha) on oviposition decisions of male and female European bitterling (Rhodeus amarus) from two populations with a different level of sympatry; b) the effect of zebra Mussel on bitterling reproductive success. We found that zebra Mussel decreased bitterling oviposition rate into the unionid Mussels in the wild and in mesocosm. There was no effect of bitterling-zebra Mussel sympatry in the wild, but a stronger decrease in bitterling reproductive success with increasing zebra Mussel fouling on unionid hosts in the mesocosm. Female bitterling used infected unionids only rarely. Sometimes, they oviposited into a zebra Mussel, followed by a failure to develop. Female decisions were active - they inspected infected and non-infected Mussels at the same rate.
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An indirect effect of biological invasions: the effect of zebra Mussel fouling on parasitisation of unionid Mussels by bitterling fish
Hydrobiologia, 2012Co-Authors: Milan Vrtílek, Martin ReichardAbstract:Invasive species represent a major threat with both direct and indirect effects on natural ecosystems, including effects on established and coevolved relationships. In a series of experiments, we examined how the interaction between two native species, a unionid Mussel (Unio pictorum) and the European bitterling (Rhodeus amarus), a fish that parasitises unionids, was affected by the non-native zebra Mussel (Dreissena polymorpha). The zebra Mussel fouls hard substrates, including shells of living unionids, and its presence is often associated with a decrease in population density of native unionid Mussels. Bitterling lay their eggs into live unionids and the embryos develop inside their gills. Using a range of zebra Mussel densities, we demonstrated that zebra Mussel fouling had a negative effect on the number of bitterling eggs inside the Mussel host, with abundances of 5–10 zebra Mussels (shell size 15–25 mm) per unionid critical for bitterling ability to utilise the host. In a further experiment, we found that bitterling did not discriminate between unfouled unionids and those fouled with five zebra Mussels. Most ovipositions into fouled hosts, however, were unsuccessful as eggs failed to reach the unionid gills. We discuss implications of such unsuccessful ovipositions for bitterling recruitment and population dynamics.
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An indirect effect of biological invasions: the effect of zebra Mussel fouling on parasitisation of unionid Mussels by bitterling fish
Hydrobiologia, 2012Co-Authors: Milan Vrtílek, Martin ReichardAbstract:Invasive species represent a major threat with both direct and indirect effects on natural ecosystems, including effects on established and coevolved relationships. In a series of experiments, we examined how the interaction between two native species, a unionid Mussel (Unio pictorum) and the European bitterling (Rhodeus amarus), a fish that parasitises unionids, was affected by the non-native zebra Mussel (Dreissena polymorpha). The zebra Mussel fouls hard substrates, including shells of living unionids, and its presence is often associated with a decrease in population density of native unionid Mussels. Bitterling lay their eggs into live unionids and the embryos develop inside their gills. Using a range of zebra Mussel densities, we demonstrated that zebra Mussel fouling had a negative effect on the number of bitterling eggs inside the Mussel host, with abundances of 5–10 zebra Mussels (shell size 15–25 mm) per unionid critical for bitterling ability to utilise the host. In a further experiment, we found that bitterling did not discriminate between unfouled unionids and those fouled with five zebra Mussels. Most ovipositions into fouled hosts, however, were unsuccessful as eggs failed to reach the unionid gills. We discuss implications of such unsuccessful ovipositions for bitterling recruitment and population dynamics.
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the bitterling Mussel coevolutionary relationship in areas of recent and ancient sympatry
Evolution, 2010Co-Authors: Martin Reichard, Matej Polačik, Ali Serhan Tarkan, Rowena Spence, Özcan Gaygusuz, Ertan Ercan, Markéta Ondračková, Carl SmithAbstract:Host-parasite relationships are often characterized by the rapid evolution of parasite adaptations to exploit their host, and counteradaptations in the host to avoid the costs imposed by parasitism. Hence, the current coevolutionary state between a parasite and its hosts is predicted to vary according to the history of sympatry and local abundance of interacting species. We compared a unique reciprocal coevolutionary relationship of a fish, the European bitterling (Rhodeus amarus) and freshwater Mussels (Unionidae) between areas of recent (Central Europe) and ancient (Turkey) sympatry. Bitterling parasitize freshwater Mussels by laying their eggs in the gills of Mussel and, in turn, Mussel larvae (glochidia) parasitize the fish. We found that all bitterling from both regions avoided one Mussel species. Preferences among other Mussel species tended to be related to local Mussel abundance rather than duration of sympatry. Individual fish were not consistent in their oviposition choices, precluding the evolution of host-specific lineages. Mussels were demonstrated to have evolved strong defenses to bitterling parasitism in the area of ancient sympatry, but have no such defenses in the large areas of Europe where bitterling are currently invasive. Bitterling avoided glochidia infection irrespective of the duration of sympatry.
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The bitterling–Mussel coevolutionary relationship in areas of recent and ancient sympatry
Evolution; international journal of organic evolution, 2010Co-Authors: Martin Reichard, Matej Polačik, Ali Serhan Tarkan, Rowena Spence, Özcan Gaygusuz, Ertan Ercan, Markéta Ondračková, Carl SmithAbstract:Host-parasite relationships are often characterized by the rapid evolution of parasite adaptations to exploit their host, and counteradaptations in the host to avoid the costs imposed by parasitism. Hence, the current coevolutionary state between a parasite and its hosts is predicted to vary according to the history of sympatry and local abundance of interacting species. We compared a unique reciprocal coevolutionary relationship of a fish, the European bitterling (Rhodeus amarus) and freshwater Mussels (Unionidae) between areas of recent (Central Europe) and ancient (Turkey) sympatry. Bitterling parasitize freshwater Mussels by laying their eggs in the gills of Mussel and, in turn, Mussel larvae (glochidia) parasitize the fish. We found that all bitterling from both regions avoided one Mussel species. Preferences among other Mussel species tended to be related to local Mussel abundance rather than duration of sympatry. Individual fish were not consistent in their oviposition choices, precluding the evolution of host-specific lineages. Mussels were demonstrated to have evolved strong defenses to bitterling parasitism in the area of ancient sympatry, but have no such defenses in the large areas of Europe where bitterling are currently invasive. Bitterling avoided glochidia infection irrespective of the duration of sympatry.
Rob S. E. W. Leuven - One of the best experts on this subject based on the ideXlab platform.
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A dominance shift from the zebra Mussel to the invasive quagga Mussel may alter the trophic transfer of metals
Environmental Pollution, 2015Co-Authors: J Matthews, Aafke M. Schipper, T. T. Y. Le, A. Bij De Vaate, Gabrielle Van Der Velde, A.j. Hendriks, Rob S. E. W. LeuvenAbstract:Bioinvasions are a major cause of biodiversity and ecosystem changes. The rapid range expansion of the invasive quagga Mussel (Dreissena rostriformis bugensis) causing a dominance shift from zebra Mussels (Dreissena polymorpha) to quagga Mussels, may alter the risk of secondary poisoning to predators. Mussel samples were collected from various water bodies in the Netherlands, divided into size classes, and analysed for metal concentrations. Concentrations of nickel and copper in quagga Mussels were significantly lower than in zebra Mussels overall. In lakes, quagga Mussels contained significantly higher concentrations of aluminium, iron and lead yet significantly lower concentrations of zinc66, cadmium111, copper, nickel, cobalt and molybdenum than zebra Mussels. In the river water type quagga Mussel soft tissues contained significantly lower concentrations of zinc66. Our results suggest that a dominance shift from zebra to quagga Mussels may reduce metal exposure of predator species.
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Rapid range expansion of the invasive quagga Mussel in relation to zebra Mussel presence in The Netherlands and Western Europe
Biological Invasions, 2013Co-Authors: J Matthews, A. Bij De Vaate, F.p.l. Collas, K.r. Koopman, Gabrielle Van Der Velde, Rob S. E. W. LeuvenAbstract:Since its appearance in 2006 in a freshwater section of the Rhine–Meuse estuary (Hollandsch Diep, The Netherlands), the non-indigenous quagga Mussel has displayed a rapid range expansion in Western Europe. However, an overview characterising the spread and impacts of the quagga Mussel in this area is currently lacking. A literature study, supplemented with field data, was performed to gather all available data and information relating to quagga Mussel dispersal. Dispersal characteristics were analysed for rate and direction and in relation to hydrological connectivity and dispersal vectors. To determine ranges of conditions suitable for quagga Mussel colonisation, physico-chemical characteristics of their habitats were analysed. After its initial arrival in the freshwater section of the Rhine-Meuse estuary and River Danube, the quagga Mussel demonstrated a rapid and continued range expansion in Western Europe. Quagga Mussels have extended their non-native range to the network of major waterways in The Netherlands and in an upstream direction in the River Rhine (Germany), its tributaries (rivers Main and Moselle) and the River Meuse (Belgium and France). The calculated average quagga Mussel dispersal rate in Europe was 120 km year−1 (range 23–383 km year−1). Hydrological connectivity is important in determining the speed with which colonisation occurs. Dispersal to water bodies disconnected from the freshwater network requires the presence of a suitable vector e.g. pleasure boats transferred over land. Upstream dispersal is primarily human mediated through the attachment of Mussels to watercraft. The relative abundance of quagga Mussel to zebra Mussel has greatly increased in a number of areas sampled in the major Dutch rivers and lakes and the rivers Main and Rhine and the Rhine–Danube Canal leading to a dominance shift from zebra Mussels to quagga Mussels. However, evidence for displacement of the zebra Mussel is limited due to the lack of temporal trends relating to the overall density of zebra and quagga Mussel.
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Rapid range expansion of the invasive quagga Mussel in relation to zebra Mussel presence in The Netherlands and Western Europe
Biological Invasions, 2013Co-Authors: J Matthews, A. Bij De Vaate, F.p.l. Collas, K.r. Koopman, G. Van Der Velde, Rob S. E. W. LeuvenAbstract:Since its appearance in 2006 in a freshwater section of the Rhine–Meuse estuary (Hollandsch Diep, The Netherlands), the non-indigenous quagga Mussel has displayed a rapid range expansion in Western Europe. However, an overview characterising the spread and impacts of the quagga Mussel in this area is currently lacking. A literature study, supplemented with field data, was performed to gather all available data and information relating to quagga Mussel dispersal. Dispersal characteristics were analysed for rate and direction and in relation to hydrological connectivity and dispersal vectors. To determine ranges of conditions suitable for quagga Mussel colonisation, physico-chemical characteristics of their habitats were analysed. After its initial arrival in the freshwater section of the Rhine-Meuse estuary and River Danube, the quagga Mussel demonstrated a rapid and continued range expansion in Western Europe. Quagga Mussels have extended their non-native range to the network of major waterways in The Netherlands and in an upstream direction in the River Rhine (Germany), its tributaries (rivers Main and Moselle) and the River Meuse (Belgium and France). The calculated average quagga Mussel dispersal rate in Europe was 120 km year−1 (range 23–383 km year−1). Hydrological connectivity is important in determining the speed with which colonisation occurs. Dispersal to water bodies disconnected from the freshwater network requires the presence of a suitable vector e.g. pleasure boats transferred over land. Upstream dispersal is primarily human mediated through the attachment of Mussels to watercraft. The relative abundance of quagga Mussel to zebra Mussel has greatly increased in a number of areas sampled in the major Dutch rivers and lakes and the rivers Main and Rhine and the Rhine–Danube Canal leading to a dominance shift from zebra Mussels to quagga Mussels. However, evidence for displacement of the zebra Mussel is limited due to the lack of temporal trends relating to the overall density of zebra and quagga Mussel.
J Matthews - One of the best experts on this subject based on the ideXlab platform.
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A dominance shift from the zebra Mussel to the invasive quagga Mussel may alter the trophic transfer of metals
Environmental Pollution, 2015Co-Authors: J Matthews, Aafke M. Schipper, T. T. Y. Le, A. Bij De Vaate, Gabrielle Van Der Velde, A.j. Hendriks, Rob S. E. W. LeuvenAbstract:Bioinvasions are a major cause of biodiversity and ecosystem changes. The rapid range expansion of the invasive quagga Mussel (Dreissena rostriformis bugensis) causing a dominance shift from zebra Mussels (Dreissena polymorpha) to quagga Mussels, may alter the risk of secondary poisoning to predators. Mussel samples were collected from various water bodies in the Netherlands, divided into size classes, and analysed for metal concentrations. Concentrations of nickel and copper in quagga Mussels were significantly lower than in zebra Mussels overall. In lakes, quagga Mussels contained significantly higher concentrations of aluminium, iron and lead yet significantly lower concentrations of zinc66, cadmium111, copper, nickel, cobalt and molybdenum than zebra Mussels. In the river water type quagga Mussel soft tissues contained significantly lower concentrations of zinc66. Our results suggest that a dominance shift from zebra to quagga Mussels may reduce metal exposure of predator species.
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Rapid range expansion of the invasive quagga Mussel in relation to zebra Mussel presence in The Netherlands and Western Europe
Biological Invasions, 2013Co-Authors: J Matthews, A. Bij De Vaate, F.p.l. Collas, K.r. Koopman, Gabrielle Van Der Velde, Rob S. E. W. LeuvenAbstract:Since its appearance in 2006 in a freshwater section of the Rhine–Meuse estuary (Hollandsch Diep, The Netherlands), the non-indigenous quagga Mussel has displayed a rapid range expansion in Western Europe. However, an overview characterising the spread and impacts of the quagga Mussel in this area is currently lacking. A literature study, supplemented with field data, was performed to gather all available data and information relating to quagga Mussel dispersal. Dispersal characteristics were analysed for rate and direction and in relation to hydrological connectivity and dispersal vectors. To determine ranges of conditions suitable for quagga Mussel colonisation, physico-chemical characteristics of their habitats were analysed. After its initial arrival in the freshwater section of the Rhine-Meuse estuary and River Danube, the quagga Mussel demonstrated a rapid and continued range expansion in Western Europe. Quagga Mussels have extended their non-native range to the network of major waterways in The Netherlands and in an upstream direction in the River Rhine (Germany), its tributaries (rivers Main and Moselle) and the River Meuse (Belgium and France). The calculated average quagga Mussel dispersal rate in Europe was 120 km year−1 (range 23–383 km year−1). Hydrological connectivity is important in determining the speed with which colonisation occurs. Dispersal to water bodies disconnected from the freshwater network requires the presence of a suitable vector e.g. pleasure boats transferred over land. Upstream dispersal is primarily human mediated through the attachment of Mussels to watercraft. The relative abundance of quagga Mussel to zebra Mussel has greatly increased in a number of areas sampled in the major Dutch rivers and lakes and the rivers Main and Rhine and the Rhine–Danube Canal leading to a dominance shift from zebra Mussels to quagga Mussels. However, evidence for displacement of the zebra Mussel is limited due to the lack of temporal trends relating to the overall density of zebra and quagga Mussel.
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Rapid range expansion of the invasive quagga Mussel in relation to zebra Mussel presence in The Netherlands and Western Europe
Biological Invasions, 2013Co-Authors: J Matthews, A. Bij De Vaate, F.p.l. Collas, K.r. Koopman, G. Van Der Velde, Rob S. E. W. LeuvenAbstract:Since its appearance in 2006 in a freshwater section of the Rhine–Meuse estuary (Hollandsch Diep, The Netherlands), the non-indigenous quagga Mussel has displayed a rapid range expansion in Western Europe. However, an overview characterising the spread and impacts of the quagga Mussel in this area is currently lacking. A literature study, supplemented with field data, was performed to gather all available data and information relating to quagga Mussel dispersal. Dispersal characteristics were analysed for rate and direction and in relation to hydrological connectivity and dispersal vectors. To determine ranges of conditions suitable for quagga Mussel colonisation, physico-chemical characteristics of their habitats were analysed. After its initial arrival in the freshwater section of the Rhine-Meuse estuary and River Danube, the quagga Mussel demonstrated a rapid and continued range expansion in Western Europe. Quagga Mussels have extended their non-native range to the network of major waterways in The Netherlands and in an upstream direction in the River Rhine (Germany), its tributaries (rivers Main and Moselle) and the River Meuse (Belgium and France). The calculated average quagga Mussel dispersal rate in Europe was 120 km year−1 (range 23–383 km year−1). Hydrological connectivity is important in determining the speed with which colonisation occurs. Dispersal to water bodies disconnected from the freshwater network requires the presence of a suitable vector e.g. pleasure boats transferred over land. Upstream dispersal is primarily human mediated through the attachment of Mussels to watercraft. The relative abundance of quagga Mussel to zebra Mussel has greatly increased in a number of areas sampled in the major Dutch rivers and lakes and the rivers Main and Rhine and the Rhine–Danube Canal leading to a dominance shift from zebra Mussels to quagga Mussels. However, evidence for displacement of the zebra Mussel is limited due to the lack of temporal trends relating to the overall density of zebra and quagga Mussel.
Carl Smith - One of the best experts on this subject based on the ideXlab platform.
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the bitterling Mussel coevolutionary relationship in areas of recent and ancient sympatry
Evolution, 2010Co-Authors: Martin Reichard, Matej Polačik, Ali Serhan Tarkan, Rowena Spence, Özcan Gaygusuz, Ertan Ercan, Markéta Ondračková, Carl SmithAbstract:Host-parasite relationships are often characterized by the rapid evolution of parasite adaptations to exploit their host, and counteradaptations in the host to avoid the costs imposed by parasitism. Hence, the current coevolutionary state between a parasite and its hosts is predicted to vary according to the history of sympatry and local abundance of interacting species. We compared a unique reciprocal coevolutionary relationship of a fish, the European bitterling (Rhodeus amarus) and freshwater Mussels (Unionidae) between areas of recent (Central Europe) and ancient (Turkey) sympatry. Bitterling parasitize freshwater Mussels by laying their eggs in the gills of Mussel and, in turn, Mussel larvae (glochidia) parasitize the fish. We found that all bitterling from both regions avoided one Mussel species. Preferences among other Mussel species tended to be related to local Mussel abundance rather than duration of sympatry. Individual fish were not consistent in their oviposition choices, precluding the evolution of host-specific lineages. Mussels were demonstrated to have evolved strong defenses to bitterling parasitism in the area of ancient sympatry, but have no such defenses in the large areas of Europe where bitterling are currently invasive. Bitterling avoided glochidia infection irrespective of the duration of sympatry.
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The bitterling–Mussel coevolutionary relationship in areas of recent and ancient sympatry
Evolution; international journal of organic evolution, 2010Co-Authors: Martin Reichard, Matej Polačik, Ali Serhan Tarkan, Rowena Spence, Özcan Gaygusuz, Ertan Ercan, Markéta Ondračková, Carl SmithAbstract:Host-parasite relationships are often characterized by the rapid evolution of parasite adaptations to exploit their host, and counteradaptations in the host to avoid the costs imposed by parasitism. Hence, the current coevolutionary state between a parasite and its hosts is predicted to vary according to the history of sympatry and local abundance of interacting species. We compared a unique reciprocal coevolutionary relationship of a fish, the European bitterling (Rhodeus amarus) and freshwater Mussels (Unionidae) between areas of recent (Central Europe) and ancient (Turkey) sympatry. Bitterling parasitize freshwater Mussels by laying their eggs in the gills of Mussel and, in turn, Mussel larvae (glochidia) parasitize the fish. We found that all bitterling from both regions avoided one Mussel species. Preferences among other Mussel species tended to be related to local Mussel abundance rather than duration of sympatry. Individual fish were not consistent in their oviposition choices, precluding the evolution of host-specific lineages. Mussels were demonstrated to have evolved strong defenses to bitterling parasitism in the area of ancient sympatry, but have no such defenses in the large areas of Europe where bitterling are currently invasive. Bitterling avoided glochidia infection irrespective of the duration of sympatry.
A. Bij De Vaate - One of the best experts on this subject based on the ideXlab platform.
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A dominance shift from the zebra Mussel to the invasive quagga Mussel may alter the trophic transfer of metals
Environmental Pollution, 2015Co-Authors: J Matthews, Aafke M. Schipper, T. T. Y. Le, A. Bij De Vaate, Gabrielle Van Der Velde, A.j. Hendriks, Rob S. E. W. LeuvenAbstract:Bioinvasions are a major cause of biodiversity and ecosystem changes. The rapid range expansion of the invasive quagga Mussel (Dreissena rostriformis bugensis) causing a dominance shift from zebra Mussels (Dreissena polymorpha) to quagga Mussels, may alter the risk of secondary poisoning to predators. Mussel samples were collected from various water bodies in the Netherlands, divided into size classes, and analysed for metal concentrations. Concentrations of nickel and copper in quagga Mussels were significantly lower than in zebra Mussels overall. In lakes, quagga Mussels contained significantly higher concentrations of aluminium, iron and lead yet significantly lower concentrations of zinc66, cadmium111, copper, nickel, cobalt and molybdenum than zebra Mussels. In the river water type quagga Mussel soft tissues contained significantly lower concentrations of zinc66. Our results suggest that a dominance shift from zebra to quagga Mussels may reduce metal exposure of predator species.
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Rapid range expansion of the invasive quagga Mussel in relation to zebra Mussel presence in The Netherlands and Western Europe
Biological Invasions, 2013Co-Authors: J Matthews, A. Bij De Vaate, F.p.l. Collas, K.r. Koopman, Gabrielle Van Der Velde, Rob S. E. W. LeuvenAbstract:Since its appearance in 2006 in a freshwater section of the Rhine–Meuse estuary (Hollandsch Diep, The Netherlands), the non-indigenous quagga Mussel has displayed a rapid range expansion in Western Europe. However, an overview characterising the spread and impacts of the quagga Mussel in this area is currently lacking. A literature study, supplemented with field data, was performed to gather all available data and information relating to quagga Mussel dispersal. Dispersal characteristics were analysed for rate and direction and in relation to hydrological connectivity and dispersal vectors. To determine ranges of conditions suitable for quagga Mussel colonisation, physico-chemical characteristics of their habitats were analysed. After its initial arrival in the freshwater section of the Rhine-Meuse estuary and River Danube, the quagga Mussel demonstrated a rapid and continued range expansion in Western Europe. Quagga Mussels have extended their non-native range to the network of major waterways in The Netherlands and in an upstream direction in the River Rhine (Germany), its tributaries (rivers Main and Moselle) and the River Meuse (Belgium and France). The calculated average quagga Mussel dispersal rate in Europe was 120 km year−1 (range 23–383 km year−1). Hydrological connectivity is important in determining the speed with which colonisation occurs. Dispersal to water bodies disconnected from the freshwater network requires the presence of a suitable vector e.g. pleasure boats transferred over land. Upstream dispersal is primarily human mediated through the attachment of Mussels to watercraft. The relative abundance of quagga Mussel to zebra Mussel has greatly increased in a number of areas sampled in the major Dutch rivers and lakes and the rivers Main and Rhine and the Rhine–Danube Canal leading to a dominance shift from zebra Mussels to quagga Mussels. However, evidence for displacement of the zebra Mussel is limited due to the lack of temporal trends relating to the overall density of zebra and quagga Mussel.
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Rapid range expansion of the invasive quagga Mussel in relation to zebra Mussel presence in The Netherlands and Western Europe
Biological Invasions, 2013Co-Authors: J Matthews, A. Bij De Vaate, F.p.l. Collas, K.r. Koopman, G. Van Der Velde, Rob S. E. W. LeuvenAbstract:Since its appearance in 2006 in a freshwater section of the Rhine–Meuse estuary (Hollandsch Diep, The Netherlands), the non-indigenous quagga Mussel has displayed a rapid range expansion in Western Europe. However, an overview characterising the spread and impacts of the quagga Mussel in this area is currently lacking. A literature study, supplemented with field data, was performed to gather all available data and information relating to quagga Mussel dispersal. Dispersal characteristics were analysed for rate and direction and in relation to hydrological connectivity and dispersal vectors. To determine ranges of conditions suitable for quagga Mussel colonisation, physico-chemical characteristics of their habitats were analysed. After its initial arrival in the freshwater section of the Rhine-Meuse estuary and River Danube, the quagga Mussel demonstrated a rapid and continued range expansion in Western Europe. Quagga Mussels have extended their non-native range to the network of major waterways in The Netherlands and in an upstream direction in the River Rhine (Germany), its tributaries (rivers Main and Moselle) and the River Meuse (Belgium and France). The calculated average quagga Mussel dispersal rate in Europe was 120 km year−1 (range 23–383 km year−1). Hydrological connectivity is important in determining the speed with which colonisation occurs. Dispersal to water bodies disconnected from the freshwater network requires the presence of a suitable vector e.g. pleasure boats transferred over land. Upstream dispersal is primarily human mediated through the attachment of Mussels to watercraft. The relative abundance of quagga Mussel to zebra Mussel has greatly increased in a number of areas sampled in the major Dutch rivers and lakes and the rivers Main and Rhine and the Rhine–Danube Canal leading to a dominance shift from zebra Mussels to quagga Mussels. However, evidence for displacement of the zebra Mussel is limited due to the lack of temporal trends relating to the overall density of zebra and quagga Mussel.
