- Email: [email protected]
Oxygen limitations at warm temperatures in migrating salmon
Abstracts / Comparative Biochemistry and Physiology, Part A 150 (2008) S167–S173
FDR =0.05). A post-hoc Tukey's test was performed to identify genes that differed among these groups. Principal component analysis was then conducted to summarize the variation in the dataset. The first principal component comprised 80% of the variation in the data, representing an expression profile that is upregulated in response to increasing acclimation temperature. Gene Ontology (GO) analysis was performed on gene lists to identify prominent biological processes represented by significant genes. Enrichment in the GO categories protein biosynthesis, proteolysis, metabolism, protein signaling, and cytoskeletal organization were identified. Thus, acclimation entails alterations in diverse functional pathways and in cellular structure. By comparing mechanisms of acclimation in this species to those in evolutionarily related stenothermal species, we hope to more fully delineate how differences in capacities for regulating transcription contribute to establishing thermal limits and sensitivities to climate change. doi:10.1016/j.cbpa.2008.04.444
C5.8 Climate change induced temperature effects: A physiological kinetic model for the incorporation of calcium and strontium in the bivalve Mytilus edulis
S169
Thermal tolerance of single larval stages has rarely been studied, eventhough the larva might be the actual physiological bottleneck of all life history stages setting distribution limits. Therefore, temperature tolerance of Zoea I was examined in two different population of the Chilean kelp crab Taliepus dentatus. We measured activity, oxygen consumption, cardiac performance and the CN composition of larval T. dentatus of two populations from central and southern Chile at various temperatures (1) to determine at which organisational level T. dentatus larvae get first affected by temperature, integrating variables from the organismal, tissue functional to the biochemical elemental level, and (2) to compare the thermal tolerance of larvae from varying environmental temperature regimes to look at functional differences between populations as a correlate of adaptation capacities of the Zoea. Our mechanistic analysis explicitly sheds light on how temperature affects the physiology of crab larvae. We found that the highest organisational level gets affected first, seen in activity decrements at unsuitably high or low temperatures, paralleled by decreases in oxygen consumption rates. Cardiac performance is more robust to temperature changes. Heart beat rate decreases only at very high and low temperature extremes and stroke volume is almost temperature independent. The comparison between the southern and central populations showed a limited but clear adaptation of larvae from the southern sampling site to the colder environmental temperature regime, visible at all organisational levels. doi:10.1016/j.cbpa.2008.04.446
H. Hanssen, R. Blust, G. de Boeck (University of Antwerp, Belgium) Calcareous skeletons are produced in a complex mineralization process which is biologically controlled and genetically programmed. Bivalves are ideal candidates for climate change induced effect studies due to their incremental shell deposition and their potential for high temporal resolution reconstructions. In order to assess climatic influences on ecosystems, evaluation of thermal limits of certain species and their ability to cope with thermal stress is required. This allows to better estimate effects such as the predicted global decrease of biological CaCO3 export production. Mineral uptake and deposition depend on climate conditions and the physiology of the organisms. Interpretation of the results is complicated by the dynamics of the seasonal and tidal cycles that determine the timing and magnitude of temperature changes and create a unique thermal signal at each location. In this study the radiotracers calcium-45 and strontium-85 were used to assess temperature effects on uptake and transfer in different compartments(soft tissues, hemolymph and shell) of the bivalve Mytilus edulis. The Sr/Ca ratio, a robust record of past sea surface temperatures in aragonite corals, could be a potential temperature proxy in bivalves shells. Recent studies however emphasize the importance of kinetic effects on strontium partitioning. We have constructed a physiological dynamic model that determines the kinetics for mineral uptake and incorporation in bivalves discriminating between the waterborne and dietary routes. By changing the values of some key parameters (e.g. uptake rates, metabolic activity, growth rates, etc.) the model may be used to predict effects under different conditions and across temperature regimes.
C5.10 Oxygen limitations at warm temperatures in migrating salmon E. Eliason, T. Clark, K. Jeffries, S. Hinch, G. Cox, C. Wilson, T. Farrell (University of British Columbia) Elevated river temperatures due to climate change during physically demanding spawning migrations have been repeatedly associated with Pacific salmon mortality. We sought to discover how cardiorespiratory performance during swimming is impeded at high temperatures. Wild, sockeye salmon were intercepted in the lower Fraser River, British Columbia, Canada during their upriver spawning migration and held in large outdoor tanks at 12 °C. Following a 3 day temperature exposure (at 15,18, 20 or 22 °C), the fish performed two consecutive ramp-Ucrit swim tests in a large, Brett-type swim tunnel with a 45 min recovery in between. Cardiac output, oxygen consumption and arterial and venous blood samples were monitored throughout the tests. Fish held at 22 °C were clearly compromised, as demonstrated by increased mortality during holding, cardiac arrhythmia during swimming and decreased aerobic and cardiac scope. These results are consistent with swimming performance, aerobic scope and cardiac scope decreasing above an optimum temperature, potentially leading to in-river mortality. Supported by NSERC Canada and BC Pacific Salmon Forum. doi:10.1016/j.cbpa.2008.04.447
doi:10.1016/j.cbpa.2008.04.445
C5.9 Temperature tolerance of Zoea I from two different populations of the kelp crab Taliepus dentatus D. Storch (Alfred Wegener Institut); H. Poertner (Alfred Wegener Institut); P. Santelices (Pontificia Universidad Católica); J. Barria (Pontificia Universidad Católica); M. Fernández (Pontificia Universidad Católica)
C5.11 Modeling of thermal and hydraulic barriers that marginalize Pacific salmon spawning migrations K. Chan (University of British Columbia); J. Li (University of British Columbia); D. Patterson (Department of Fisheries and Oceans Canada); M. Hague (Department of Fisheries and Oceans Canada); A. Farrell (University of British Columbia)
FDR =0.05). A post-hoc Tukey's test was performed to identify genes that differed among these groups. Principal component analysis was then conducted to summarize the variation in the dataset. The first principal component comprised 80% of the variation in the data, representing an expression profile that is upregulated in response to increasing acclimation temperature. Gene Ontology (GO) analysis was performed on gene lists to identify prominent biological processes represented by significant genes. Enrichment in the GO categories protein biosynthesis, proteolysis, metabolism, protein signaling, and cytoskeletal organization were identified. Thus, acclimation entails alterations in diverse functional pathways and in cellular structure. By comparing mechanisms of acclimation in this species to those in evolutionarily related stenothermal species, we hope to more fully delineate how differences in capacities for regulating transcription contribute to establishing thermal limits and sensitivities to climate change. doi:10.1016/j.cbpa.2008.04.444
C5.8 Climate change induced temperature effects: A physiological kinetic model for the incorporation of calcium and strontium in the bivalve Mytilus edulis
S169
Thermal tolerance of single larval stages has rarely been studied, eventhough the larva might be the actual physiological bottleneck of all life history stages setting distribution limits. Therefore, temperature tolerance of Zoea I was examined in two different population of the Chilean kelp crab Taliepus dentatus. We measured activity, oxygen consumption, cardiac performance and the CN composition of larval T. dentatus of two populations from central and southern Chile at various temperatures (1) to determine at which organisational level T. dentatus larvae get first affected by temperature, integrating variables from the organismal, tissue functional to the biochemical elemental level, and (2) to compare the thermal tolerance of larvae from varying environmental temperature regimes to look at functional differences between populations as a correlate of adaptation capacities of the Zoea. Our mechanistic analysis explicitly sheds light on how temperature affects the physiology of crab larvae. We found that the highest organisational level gets affected first, seen in activity decrements at unsuitably high or low temperatures, paralleled by decreases in oxygen consumption rates. Cardiac performance is more robust to temperature changes. Heart beat rate decreases only at very high and low temperature extremes and stroke volume is almost temperature independent. The comparison between the southern and central populations showed a limited but clear adaptation of larvae from the southern sampling site to the colder environmental temperature regime, visible at all organisational levels. doi:10.1016/j.cbpa.2008.04.446
H. Hanssen, R. Blust, G. de Boeck (University of Antwerp, Belgium) Calcareous skeletons are produced in a complex mineralization process which is biologically controlled and genetically programmed. Bivalves are ideal candidates for climate change induced effect studies due to their incremental shell deposition and their potential for high temporal resolution reconstructions. In order to assess climatic influences on ecosystems, evaluation of thermal limits of certain species and their ability to cope with thermal stress is required. This allows to better estimate effects such as the predicted global decrease of biological CaCO3 export production. Mineral uptake and deposition depend on climate conditions and the physiology of the organisms. Interpretation of the results is complicated by the dynamics of the seasonal and tidal cycles that determine the timing and magnitude of temperature changes and create a unique thermal signal at each location. In this study the radiotracers calcium-45 and strontium-85 were used to assess temperature effects on uptake and transfer in different compartments(soft tissues, hemolymph and shell) of the bivalve Mytilus edulis. The Sr/Ca ratio, a robust record of past sea surface temperatures in aragonite corals, could be a potential temperature proxy in bivalves shells. Recent studies however emphasize the importance of kinetic effects on strontium partitioning. We have constructed a physiological dynamic model that determines the kinetics for mineral uptake and incorporation in bivalves discriminating between the waterborne and dietary routes. By changing the values of some key parameters (e.g. uptake rates, metabolic activity, growth rates, etc.) the model may be used to predict effects under different conditions and across temperature regimes.
C5.10 Oxygen limitations at warm temperatures in migrating salmon E. Eliason, T. Clark, K. Jeffries, S. Hinch, G. Cox, C. Wilson, T. Farrell (University of British Columbia) Elevated river temperatures due to climate change during physically demanding spawning migrations have been repeatedly associated with Pacific salmon mortality. We sought to discover how cardiorespiratory performance during swimming is impeded at high temperatures. Wild, sockeye salmon were intercepted in the lower Fraser River, British Columbia, Canada during their upriver spawning migration and held in large outdoor tanks at 12 °C. Following a 3 day temperature exposure (at 15,18, 20 or 22 °C), the fish performed two consecutive ramp-Ucrit swim tests in a large, Brett-type swim tunnel with a 45 min recovery in between. Cardiac output, oxygen consumption and arterial and venous blood samples were monitored throughout the tests. Fish held at 22 °C were clearly compromised, as demonstrated by increased mortality during holding, cardiac arrhythmia during swimming and decreased aerobic and cardiac scope. These results are consistent with swimming performance, aerobic scope and cardiac scope decreasing above an optimum temperature, potentially leading to in-river mortality. Supported by NSERC Canada and BC Pacific Salmon Forum. doi:10.1016/j.cbpa.2008.04.447
doi:10.1016/j.cbpa.2008.04.445
C5.9 Temperature tolerance of Zoea I from two different populations of the kelp crab Taliepus dentatus D. Storch (Alfred Wegener Institut); H. Poertner (Alfred Wegener Institut); P. Santelices (Pontificia Universidad Católica); J. Barria (Pontificia Universidad Católica); M. Fernández (Pontificia Universidad Católica)
C5.11 Modeling of thermal and hydraulic barriers that marginalize Pacific salmon spawning migrations K. Chan (University of British Columbia); J. Li (University of British Columbia); D. Patterson (Department of Fisheries and Oceans Canada); M. Hague (Department of Fisheries and Oceans Canada); A. Farrell (University of British Columbia)