The Experts below are selected from a list of 150891 Experts worldwide ranked by ideXlab platform
Clement Lagrue - One of the best experts on this subject based on the ideXlab platform.
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effects of crayfish on leaf litter breakdown and shredder prey are native and Introduced Species functionally redundant
Biological Invasions, 2014Co-Authors: L Dunoyer, L Dijoux, Loic Bollache, Clement LagrueAbstract:Recent increases in biological invasions frequency may have important consequences on native communities. However, functional redundancy between invasive and native Species could reduce non-native Species effects on native ecosystems. Despite this, even small differences in functional traits between these Species may still have unpredictable effects on colonized ecosystems. Invasive crayfish, as ecosystem engineers, potentially have wide and complex effects on recipient ecosystems, even when replacing a native counterpart. We used laboratory microcosms to test whether native (Astacus astacus) and invasive crayfish Species (Orconectes limosus, Pacifastacus leniusculus and Procambarus clarkii) are actually functionally redundant in their effects on prey/shredder density and leaf litter breakdown. Results show that crayfish strongly influenced macroinvertebrate numbers and leaf litter breakdown and indicate that differences in direct (prey and leaf litter consumption) and indirect (prey habitat use and leaf litter breakdown) effects between crayfish Species do exist. While the replacement of A. astacus by O. limosus may have induced only minor changes in freshwater ecosystems, invasions by the larger and more aggressive P. clarkii and P. leniusculus will likely have strong effects on invaded ecosystem. Overall, there seems to be no functional redundancy between these four Species and outcomes of crayfish invasion will likely be Species specific.
Loic Bollache - One of the best experts on this subject based on the ideXlab platform.
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effects of crayfish on leaf litter breakdown and shredder prey are native and Introduced Species functionally redundant
Biological Invasions, 2014Co-Authors: L Dunoyer, L Dijoux, Loic Bollache, Clement LagrueAbstract:Recent increases in biological invasions frequency may have important consequences on native communities. However, functional redundancy between invasive and native Species could reduce non-native Species effects on native ecosystems. Despite this, even small differences in functional traits between these Species may still have unpredictable effects on colonized ecosystems. Invasive crayfish, as ecosystem engineers, potentially have wide and complex effects on recipient ecosystems, even when replacing a native counterpart. We used laboratory microcosms to test whether native (Astacus astacus) and invasive crayfish Species (Orconectes limosus, Pacifastacus leniusculus and Procambarus clarkii) are actually functionally redundant in their effects on prey/shredder density and leaf litter breakdown. Results show that crayfish strongly influenced macroinvertebrate numbers and leaf litter breakdown and indicate that differences in direct (prey and leaf litter consumption) and indirect (prey habitat use and leaf litter breakdown) effects between crayfish Species do exist. While the replacement of A. astacus by O. limosus may have induced only minor changes in freshwater ecosystems, invasions by the larger and more aggressive P. clarkii and P. leniusculus will likely have strong effects on invaded ecosystem. Overall, there seems to be no functional redundancy between these four Species and outcomes of crayfish invasion will likely be Species specific.
Jan H Sundet - One of the best experts on this subject based on the ideXlab platform.
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the norwegian management of an Introduced Species the arctic red king crab fishery
Marine Policy, 2016Co-Authors: Jan H Sundet, Alf Hakon HoelAbstract:Abstract Introduced into the Barents Sea in the 1960s, the red king crab ( Paralithodes camtschaticus ) has been fished commercially in Norway since 2002. Because it is an Introduced Species, its management raises a number of concerns. Minimising the threats posed by non-native Species that cannot be eradicated is a challenge facing nature management authorities worldwide. High concentrations of crab on fishing grounds in eastern Finnmark in North Norway have interfered with traditional gillnet and longline fisheries, prompting fishermen to demand compensation for lost income. Difficult trade-offs were posed by the dual management objectives, which included (i) preventing the geographical expansion of the crab and (ii) exploiting the resource to provide income to coastal communities. The Norwegian government, with the consent of Parliament, has developed a management regime that addresses both objectives: an open-access fishery west of 26°E to prevent further west- and southward expansion of the crab population, and a regular commercial fishery east of that longitude. This management regime commands wider consideration, owing to its handling of the dilemmas inherent in the management of Introduced Species.
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the Introduced Species red king crab paralithodes camtschaticus in the barents sea ii growth increments and moulting probability
Fisheries Research, 2006Co-Authors: Einar M Nilssen, Jan H SundetAbstract:Russian scientists Introduced the red king crab (Paralithodes camtschaticus) to the Barents Sea during the 1960s and 1970s, and the crab has now become abundant in the coastal waters of Finnmark, North Norway. The growing stock size of this Introduced Species raises increasing demands for management of the stock. Therefore, basic knowledge of general biology and ecology is required. This paper presents analyses of the moulting increment and moulting frequency results based on tag and recapture experiments. The mean increments in carapace length per moult of males (immature and mature) are estimated to be 17.0 mm for all premoult carapace lengths between 67 and 172 mm, while the increment decreased from 14.4 to 5.1 mm for females as they became ovigerous. The results show that the growth increments of the red king crab in Varanger are within the ranges reported in the eastern Bering Sea. A model relating probability of moulting as a function of carapace length is developed based on tag-recapture and qualitative carapace age judgement.
Alain Crivelli - One of the best experts on this subject based on the ideXlab platform.
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Can life-history traits predict the fate of Introduced Species? A case study on two cyprinid fish in southern France
Freshwater Biology, 2001Co-Authors: Elisabeth Rosecchi, Frédéric Thomas, Alain CrivelliAbstract:1. The ecological and economic costs of Introduced Species can be high. Ecologists try to predict the probability of success and potential risk of the establishment of recently Introduced Species, given their biological characteristics. 2. In 1990 gudgeon, Gobio gobio, were released in a drainage canal of the Rhône delta of southern France. The Asian topmouth gudgeon, Pseudorasbora parva, was found for the first time in the same canal in 1993. Those introductions offered a unique opportunity to compare in situ the fate of two closely related fish in the same habitat. 3. Our major aims were to assess whether G. gobio was able to establish in what seemed an unlikely environment, to compare populations trends and life‐history traits of both Species and to assess whether we could explain or could have predicted our results, by considering their life‐history strategies. 4. Data show that both Species have established in the canal and have spread. Catches of P. parva have increased strongly and are now higher than those of G. gobio. 5. The two cyprinids have the same breeding season and comparable traits (such as short generation time, small body, high reproductive effort), so both could be classified as opportunists. The observed difference in their success (in terms of population growth and colonization rate) could be explained by the wider ecological and physiological tolerance of P. parva. 6. In conclusion, our field study seems to suggest that invasive vigour also results from the ability to tolerate environmental changes through phenotypic plasticity, rather than from particular life‐history features pre‐adapted to invasion. It thus remains difficult to define a good invader simply on the basis of its life‐history features.
L Dunoyer - One of the best experts on this subject based on the ideXlab platform.
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effects of crayfish on leaf litter breakdown and shredder prey are native and Introduced Species functionally redundant
Biological Invasions, 2014Co-Authors: L Dunoyer, L Dijoux, Loic Bollache, Clement LagrueAbstract:Recent increases in biological invasions frequency may have important consequences on native communities. However, functional redundancy between invasive and native Species could reduce non-native Species effects on native ecosystems. Despite this, even small differences in functional traits between these Species may still have unpredictable effects on colonized ecosystems. Invasive crayfish, as ecosystem engineers, potentially have wide and complex effects on recipient ecosystems, even when replacing a native counterpart. We used laboratory microcosms to test whether native (Astacus astacus) and invasive crayfish Species (Orconectes limosus, Pacifastacus leniusculus and Procambarus clarkii) are actually functionally redundant in their effects on prey/shredder density and leaf litter breakdown. Results show that crayfish strongly influenced macroinvertebrate numbers and leaf litter breakdown and indicate that differences in direct (prey and leaf litter consumption) and indirect (prey habitat use and leaf litter breakdown) effects between crayfish Species do exist. While the replacement of A. astacus by O. limosus may have induced only minor changes in freshwater ecosystems, invasions by the larger and more aggressive P. clarkii and P. leniusculus will likely have strong effects on invaded ecosystem. Overall, there seems to be no functional redundancy between these four Species and outcomes of crayfish invasion will likely be Species specific.
