The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Juergen Geist - One of the best experts on this subject based on the ideXlab platform.
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fine sediment as Environmental Stressor affecting freshwater mussel behavior and ecosystem services
Science of The Total Environment, 2016Co-Authors: Evamaria Lummer, K Auerswald, Juergen GeistAbstract:Abstract Fine sediment pollution is considered a major Stressor for aquatic ecosystems and their biodiversity. In particular, fine sediments have been suggested to play a crucial role in the declines of freshwater mussels which are considered keystone fauna of streams and rivers. Whereas the effects of deposited fine sediments on recruitment failure are well known, effects of suspended fine sediments on adult mussel behavior are less studied. Therefore the aim of this study was to investigate the effects of fine sediment exposure on freshwater mussel behavior and on mussel-dependent ecosystem services. Unio pictorum mussels were used to test three behavioral endpoints: Hall activity, transition frequency and relative water clearance rate. Mussels were exposed to fine sediments of different particle size classes ( − 1 ) of the smallest particle size class. Hall sensor technology and turbidity measurements were used to detect mussel behavior in presence of suspended sediments. Results revealed that mussels improve clearance of suspended particles out of the water column by 35%, independent of particle size class and concentration. Transition frequency was determined an unsuitable behavioral endpoint for non-soluble substances. Contrary to previous studies, we could demonstrate that fine sediments do not interfere with filtration by mussels and that mussels have a great influence on water purification, providing a valuable ecosystem service.
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fine sediment as Environmental Stressor affecting freshwater mussel behavior and ecosystem services
Science of The Total Environment, 2016Co-Authors: Evamaria Lummer, K Auerswald, Juergen GeistAbstract:Fine sediment pollution is considered a major Stressor for aquatic ecosystems and their biodiversity. In particular, fine sediments have been suggested to play a crucial role in the declines of freshwater mussels which are considered keystone fauna of streams and rivers. Whereas the effects of deposited fine sediments on recruitment failure are well known, effects of suspended fine sediments on adult mussel behavior are less studied. Therefore the aim of this study was to investigate the effects of fine sediment exposure on freshwater mussel behavior and on mussel-dependent ecosystem services. Unio pictorum mussels were used to test three behavioral endpoints: Hall activity, transition frequency and relative water clearance rate. Mussels were exposed to fine sediments of different particle size classes (<45μm, 45-63μm, 63-125μm) and different concentration (0-10gL(-1)) of the smallest particle size class. Hall sensor technology and turbidity measurements were used to detect mussel behavior in presence of suspended sediments. Results revealed that mussels improve clearance of suspended particles out of the water column by 35%, independent of particle size class and concentration. Transition frequency was determined an unsuitable behavioral endpoint for non-soluble substances. Contrary to previous studies, we could demonstrate that fine sediments do not interfere with filtration by mussels and that mussels have a great influence on water purification, providing a valuable ecosystem service.
Mike Letnic - One of the best experts on this subject based on the ideXlab platform.
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interactions between corticosterone phenotype Environmental Stressor pervasiveness and irruptive movement related survival in the cane toad
The Journal of Experimental Biology, 2018Co-Authors: Tim S Jessop, Jonathan K Webb, Tim Dempster, Benjamin Feit, Mike LetnicAbstract:Animals use irruptive movement to avoid exposure to stochastic and pervasive Environmental Stressors that impact fitness. Beneficial irruptive movements transfer individuals from high-stress areas (conferring low fitness) to alternative localities that may improve survival or reproduction. However, being stochastic, Environmental Stressors can limit an animal's preparatory capacity to enhance irruptive movement performance. Thus individuals must rely on pre-existing, or rapidly induced, physiological and behavioural responses. Rapid elevation of glucocorticoid hormones in response to Environmental Stressors are widely implicated in adjusting physiological and behaviour processes that could influence irruptive movement capacity. However, there remains little direct evidence demonstrating that corticosterone-regulated movement performance or interaction with pervasiveness of Environmental stress, confers adaptive movement outcomes. Here, we compared how movement-related survival of cane toads (Rhinella marina) varied with three different experimental corticosterone phenotypes across four increments of increasing Environmental Stressor pervasiveness (i.e. distance from water in a semi-arid landscape). Our results indicated that toads with phenotypically increased corticosterone levels attained higher movement-related survival compared with individuals with control or lowered corticosterone phenotypes. However, the effects of corticosterone phenotypes on movement-related survival to some extent co-varied with Stressor pervasiveness. Thus, our study demonstrates how the interplay between an individual's corticosterone phenotype and movement capacity alongside the arising costs of movement and the pervasiveness of the Environmental Stressor can affect survival outcomes.
Benjamin Feit - One of the best experts on this subject based on the ideXlab platform.
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interactions between corticosterone phenotype Environmental Stressor pervasiveness and irruptive movement related survival in the cane toad
The Journal of Experimental Biology, 2018Co-Authors: Tim S Jessop, Jonathan K Webb, Tim Dempster, Benjamin Feit, Mike LetnicAbstract:Animals use irruptive movement to avoid exposure to stochastic and pervasive Environmental Stressors that impact fitness. Beneficial irruptive movements transfer individuals from high-stress areas (conferring low fitness) to alternative localities that may improve survival or reproduction. However, being stochastic, Environmental Stressors can limit an animal's preparatory capacity to enhance irruptive movement performance. Thus individuals must rely on pre-existing, or rapidly induced, physiological and behavioural responses. Rapid elevation of glucocorticoid hormones in response to Environmental Stressors are widely implicated in adjusting physiological and behaviour processes that could influence irruptive movement capacity. However, there remains little direct evidence demonstrating that corticosterone-regulated movement performance or interaction with pervasiveness of Environmental stress, confers adaptive movement outcomes. Here, we compared how movement-related survival of cane toads (Rhinella marina) varied with three different experimental corticosterone phenotypes across four increments of increasing Environmental Stressor pervasiveness (i.e. distance from water in a semi-arid landscape). Our results indicated that toads with phenotypically increased corticosterone levels attained higher movement-related survival compared with individuals with control or lowered corticosterone phenotypes. However, the effects of corticosterone phenotypes on movement-related survival to some extent co-varied with Stressor pervasiveness. Thus, our study demonstrates how the interplay between an individual's corticosterone phenotype and movement capacity alongside the arising costs of movement and the pervasiveness of the Environmental Stressor can affect survival outcomes.
Evamaria Lummer - One of the best experts on this subject based on the ideXlab platform.
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fine sediment as Environmental Stressor affecting freshwater mussel behavior and ecosystem services
Science of The Total Environment, 2016Co-Authors: Evamaria Lummer, K Auerswald, Juergen GeistAbstract:Abstract Fine sediment pollution is considered a major Stressor for aquatic ecosystems and their biodiversity. In particular, fine sediments have been suggested to play a crucial role in the declines of freshwater mussels which are considered keystone fauna of streams and rivers. Whereas the effects of deposited fine sediments on recruitment failure are well known, effects of suspended fine sediments on adult mussel behavior are less studied. Therefore the aim of this study was to investigate the effects of fine sediment exposure on freshwater mussel behavior and on mussel-dependent ecosystem services. Unio pictorum mussels were used to test three behavioral endpoints: Hall activity, transition frequency and relative water clearance rate. Mussels were exposed to fine sediments of different particle size classes ( − 1 ) of the smallest particle size class. Hall sensor technology and turbidity measurements were used to detect mussel behavior in presence of suspended sediments. Results revealed that mussels improve clearance of suspended particles out of the water column by 35%, independent of particle size class and concentration. Transition frequency was determined an unsuitable behavioral endpoint for non-soluble substances. Contrary to previous studies, we could demonstrate that fine sediments do not interfere with filtration by mussels and that mussels have a great influence on water purification, providing a valuable ecosystem service.
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fine sediment as Environmental Stressor affecting freshwater mussel behavior and ecosystem services
Science of The Total Environment, 2016Co-Authors: Evamaria Lummer, K Auerswald, Juergen GeistAbstract:Fine sediment pollution is considered a major Stressor for aquatic ecosystems and their biodiversity. In particular, fine sediments have been suggested to play a crucial role in the declines of freshwater mussels which are considered keystone fauna of streams and rivers. Whereas the effects of deposited fine sediments on recruitment failure are well known, effects of suspended fine sediments on adult mussel behavior are less studied. Therefore the aim of this study was to investigate the effects of fine sediment exposure on freshwater mussel behavior and on mussel-dependent ecosystem services. Unio pictorum mussels were used to test three behavioral endpoints: Hall activity, transition frequency and relative water clearance rate. Mussels were exposed to fine sediments of different particle size classes (<45μm, 45-63μm, 63-125μm) and different concentration (0-10gL(-1)) of the smallest particle size class. Hall sensor technology and turbidity measurements were used to detect mussel behavior in presence of suspended sediments. Results revealed that mussels improve clearance of suspended particles out of the water column by 35%, independent of particle size class and concentration. Transition frequency was determined an unsuitable behavioral endpoint for non-soluble substances. Contrary to previous studies, we could demonstrate that fine sediments do not interfere with filtration by mussels and that mussels have a great influence on water purification, providing a valuable ecosystem service.
Christian E W Steinberg - One of the best experts on this subject based on the ideXlab platform.
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interaction of temperature and an Environmental Stressor moina macrocopa responds with increased body size increased lifespan and increased offspring numbers slightly above its temperature optimum
Chemosphere, 2013Co-Authors: Antonia Engert, Shumon Chakrabarti, Nadine Saul, Michal Bittner, Ralph Menzel, Christian E W SteinbergAbstract:For organisms, temperature is one of the most important Environmental factors and gains increasing importance due to global warming, since increasing temperatures may pose organisms close to their Environmental tolerance limits and, thus, they may become more vulnerable to Environmental Stressors. We analyzed the temperature-dependence of the water-soluble antioxidant capacity of the cladoceran Moine macrocopa and evaluated its life trait variables with temperature (15, 20, 25, 30 degrees C) and humic substance (HS) concentrations (0, 0.18, 0.36, 0.90, 1.79 mM DOC) as Stressors. Temperatures below and above the apparent optimum (20 degrees C) reduced the antioxidative capacity. Additions of HSs increased body length, but decreased mean lifespan at 15 and 20 degrees C. There was no clear HS-effect on offspring numbers at 15, 20, and 30 degrees C. At 25 degrees C with increasing HS-concentration, lifespan was extended and offspring numbers increased tremendously, reaching 250% of the control. Although the applied HS preparation possesses estrogenic and antiandrogenic activities, a xenohormone mechanism does not seem plausible for the reproductive increase, because comparable effects did not occur at other temperatures. A more convincing explanation appears to be the mitohormesis hypothesis which states that a certain increase of reactive oxygen production leads to improved health and longevity and, with Moina, also to increased offspring numbers. Our results suggest that at least with the eurythermic M. macrocopa, a temperature above the optimum can be beneficial for several life trait variables, even when combined with a chemical Stressor. Temperatures approximately 10 degrees C above its optimum appear to adversely affect the lifespan and reproduction of M. macrocopa. This indicates that this cladoceran species seems to be able to utilize temperature as an ecological resource in a range slightly above its thermal optimum. (C) 2012 Elsevier Ltd. All rights reserved.
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interaction of temperature and an Environmental Stressor moina macrocopa responds with increased body size increased lifespan and increased offspring numbers slightly above its temperature optimum
Chemosphere, 2013Co-Authors: Antonia Engert, Shumon Chakrabarti, Nadine Saul, Michal Bittner, Ralph Menzel, Christian E W SteinbergAbstract:For organisms, temperature is one of the most important Environmental factors and gains increasing importance due to global warming, since increasing temperatures may pose organisms close to their Environmental tolerance limits and, thus, they may become more vulnerable to Environmental Stressors. We analyzed the temperature-dependence of the water-soluble antioxidant capacity of the cladoceran Moina macrocopa and evaluated its life trait variables with temperature (15, 20, 25, 30°C) and humic substance (HS) concentrations (0, 0.18, 0.36, 0.90, 1.79 mM DOC) as Stressors. Temperatures below and above the apparent optimum (20°C) reduced the antioxidative capacity. Additions of HSs increased body length, but decreased mean lifespan at 15 and 20°C. There was no clear HS-effect on offspring numbers at 15, 20, and 30°C. At 25°C with increasing HS-concentration, lifespan was extended and offspring numbers increased tremendously, reaching 250% of the control. Although the applied HS preparation possesses estrogenic and antiandrogenic activities, a xenohormone mechanism does not seem plausible for the reproductive increase, because comparable effects did not occur at other temperatures. A more convincing explanation appears to be the mitohormesis hypothesis which states that a certain increase of reactive oxygen production leads to improved health and longevity and, with Moina, also to increased offspring numbers. Our results suggest that at least with the eurythermic M. macrocopa, a temperature above the optimum can be beneficial for several life trait variables, even when combined with a chemical Stressor. Temperatures approximately 10°C above its optimum appear to adversely affect the lifespan and reproduction of M. macrocopa. This indicates that this cladoceran species seems to be able to utilize temperature as an ecological resource in a range slightly above its thermal optimum.