The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Michael T. Brett - One of the best experts on this subject based on the ideXlab platform.
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modelling the role of highly unsaturated fatty acids in planktonic food web processes sensitivity analysis and examination of contemporary hypotheses
Ecological Informatics, 2013Co-Authors: Gurbir Perhar, George B Arhonditsis, Michael T. BrettAbstract:Abstract Aquatic food web models typically treat the constituent trophic levels as static elements interacting with one another and the environment. Dynamic biological stoichiometry has relaxed this assumption and considers evolutionary responses in said elements. The incorporation of organismal response in food web models holds promise for a more realistic portrayal of ecosystem dynamics. Recent advances in Aquatic Ecology pinpoint the importance of highly unsaturated fatty acids (HUFAs) on food web interactions and ecosystem resilience. In this study, we utilized a HUFA explicit submodel in conjunction with a limiting nutrient–phytoplankton–zooplankton–detritus (NPZD) mathematical system to incorporate elements of the physiology of individual animals into the context of plankton dynamics. Our HUFA-augmented plankton model provided a realistic platform to examine functional properties and physiological strategies that modulate resource procurement in different trophic environments and to effectively link variability at the organismal level with ecosystem-scale patterns. First, we were able to illustrate the implications of the filling-cup hypothesis, in which species’ fitness stems from dynamic HUFA turnover rates in response to bottom-up stresses. We then examined an evolutionary hypothesis of consumer fitness dependence on HUFA quota management strategies, whereby adaptive individuals with low HUFA minimum and optimum requirements gain competitive advantage. Several studies have reported higher HUFA concentrations in consumers than producers, and our results suggest that this pattern could be driven by a combination of conservative turnover and elevated bioconversion rates. Oligotrophic settings showed strong reliance upon exogenous phosphorus subsidies and frequently yielded inverted food web biomass distributions. With the prevalence of eutrophic conditions, consumer growth is primarily controlled by HUFA availability, and the associated biochemical limitation can ultimately result in patterns of algal accumulation. Finally, our study discusses directions to improve the representation of the producer–grazer interactions and thus advance our understanding of the factors that determine the flow of nutrients and energy to the higher trophic levels.
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lipids in Aquatic ecosystems
2009Co-Authors: Michael T Arts, Michael T. Brett, Martin J KainzAbstract:Preface.- Introduction.- Algal Lipids and Effect of the Environment on their Biochemistry.- Formation and transfer of fatty acids in Aquatic microbial food webs - role of heterotrophic protists.- Ecological significance of sterols in Aquatic food webs.- Fatty acids and oxylipins as semiochemicals.- Integrating lipids and contaminants in Aquatic Ecology and ecotoxicology.- Crustacean zooplankton fatty acid composition.- Fatty acid ratios in freshwater fish, zooplankton and zoobenthos - are there specific optima?- Preliminary estimates of the export of omega-3 highly unsaturated fatty acids (EPA+DHA) from Aquatic to terrestrial ecosystems.- Biosynthesis of polyunsaturated fatty acids in Aquatic ecosystems: general pathways and new directions.- Health and condition in fish: the influence of lipids on membrane competency and immune response.- Lipids in marine copepods: latitudinal characteristics and perspective to global warming.- Lipids in marine copepods: latitudinal characteristics and perspective to global warming.- Tracing Aquatic food webs using fatty acids: from qualitative indicators to quantitative determination.- Essential fatty acids in Aquatic food webs.- Human life: caught in the food web.
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the role of highly unsaturated fatty acids in Aquatic foodweb processes
Freshwater Biology, 1997Co-Authors: Michael T. Brett, Dorthe C MullernavarraAbstract:1. Polyunsaturated fatty acids (PUFA) are almost exclusively synthesized by plants. Animals can convert from one form of PUFA to another through elongation and desaturation, but very few can synthesize PUFA de novo. PUFA play an important role in regulating cell membrane properties, serve as precursors for important animal hormones and are essential for animals. 2. In aquaculture studies, highly unsaturated fatty acids (HUFA), a subset of PUFA, have been found to be critical for maintaining high growth, survival and reproductive rates and high food conversion efficiencies for a wide variety of marine and freshwater organisms. 3. The plankton literature suggests high food-quality algae species are rich in HUFA and low food-quality algae are poor in HUFA. Adding semi-pure emulsions of HUFA to algae monocultures can markedly increase the growth rates of zooplankton feeding on these mixtures. 4. A study measuring zooplankton biomass accrual when feeding on natural phytoplankton found a strong correlation between phytoplankton HUFA (specifically eicosapentaenoic acid) content and herbivorous zooplankton production. 5. The Aquatic Ecology literature suggests that planktonic foodwebs with high HUFA content phytoplankton have high zooplankton to phytoplankton biomass ratios, while systems with low HUFA phytoplankton have low zooplankton biomass. Also, the seasonal succession of plankton in many temperate lakes follows patterns tied to phytoplankton HUFA content, with intense zooplankton grazing and ‘clear-water-phases’ characteristic of periods when the phytoplankton is dominated by HUFA-rich species. 6. Herbivorous zooplankton production is constrained by the zooplankton’s ability to ingest and digest phytoplankton. It is becoming increasingly clear, however, that much of the phytoplankton which is assimilated may be nutritionally inadequate. HUFA may be key nutritional constituents of zooplankton diets, and may determine energetic efficiency across the plant–animal interface, secondary production and the strength of trophic coupling in Aquatic pelagic foodwebs.
Wolf M Mooij - One of the best experts on this subject based on the ideXlab platform.
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fabm pclake linking Aquatic Ecology with hydrodynamics
Geoscientific Model Development, 2016Co-Authors: Karsten Bolding, Jorn Bruggeman, Erik Jeppesen, Morgens R Flindt, Luuk P A Van Gerven, Jan H Janse, Annette B G Janssen, Jan J Kuiper, Wolf M MooijAbstract:Abstract. This study presents FABM-PCLake, a redesigned structure of the PCLake Aquatic ecosystem model, which we implemented in the Framework for Aquatic Biogeochemical Models (FABM). In contrast to the original model, which was designed for temperate, fully mixed freshwater lakes, the new FABM-PCLake represents an integrated Aquatic ecosystem model that can be linked with different hydrodynamic models and allows simulations of hydrodynamic and biogeochemical processes for zero-dimensional, one-dimensional as well as three-dimensional environments. FABM-PCLake describes interactions between multiple trophic levels, including piscivorous, zooplanktivorous and benthivorous fish, zooplankton, zoobenthos, three groups of phytoplankton and rooted macrophytes. The model also accounts for oxygen dynamics and nutrient cycling for nitrogen, phosphorus and silicon, both within the pelagic and benthic domains. FABM-PCLake includes a two-way communication between the biogeochemical processes and the physics, where some biogeochemical state variables (e.g., phytoplankton) influence light attenuation and thereby the spatial and temporal distributions of light and heat. At the same time, the physical environment, including water currents, light and temperature influence a wide range of biogeochemical processes. The model enables studies on ecosystem dynamics in physically heterogeneous environments (e.g., stratifying water bodies, and water bodies with horizontal gradients in physical and biogeochemical properties), and through FABM also enables data assimilation and multi-model ensemble simulations. Examples of potential new model applications include climate change impact studies and environmental impact assessment scenarios for temperate, sub-tropical and tropical lakes and reservoirs.
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fabm pclake linking Aquatic Ecology with hydrodynamics model description paper
Geoscientific Model Development, 2016Co-Authors: Karsten Bolding, Jorn Bruggeman, Erik Jeppesen, Morgens R Flindt, Luuk P A Van Gerven, Jan H Janse, Annette B G Janssen, Jan J Kuiper, Wolf M Mooij, Dennis TrolleAbstract:This study presents FABM-PCLake, a complete redesign of the PCLake Aquatic ecosystem model, which we implemented into the Framework for Aquatic Biogeochemical Models (FABM). In contrast to the original model, which was designed for temperate, fully mixed freshwater lakes, the new FABM-PCLake represents an integrated Aquatic ecosystem model that enables simulations of hydrodynamics and biogeochemical processes for zero dimensional, one-dimensional as well as three-dimensional heterogeneous environments. FABM-PCLake describes interactions between multiple trophic levels, including piscivorous, zooplanktivorous and benthivorous fish, zooplankton, zoobenthos, three groups of phytoplankton and rooted macrophytes. The model also accounts for oxygen dynamics and nutrient cycling for nitrogen, phosphorus and silicon, both within the pelagic and benthic domains. FABM-PCLake includes a two-way communication between the biogeochemical processes and the physics, where some biogeochemical state variables (e.g., phytoplankton) influence light attenuation and thereby the spatial and temporal distributions of light and heat. At the same time, the physical environment, including water currents, light and temperature influence a wide range of biogeochemical processes. The model enables studies on ecosystem dynamics in physically heterogeneous environments (e.g., stratifying water bodies, and water bodies with horizontal gradient in physical and biogeochemical properties), and through FABM also enables data assimilation and multi-model ensemble simulations. Examples of relevant model applications include climate change impact studies and environmental impact assessment scenarios for lakes and reservoirs worldwide.
Erik Jeppesen - One of the best experts on this subject based on the ideXlab platform.
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fabm pclake linking Aquatic Ecology with hydrodynamics
Geoscientific Model Development, 2016Co-Authors: Karsten Bolding, Jorn Bruggeman, Erik Jeppesen, Morgens R Flindt, Luuk P A Van Gerven, Jan H Janse, Annette B G Janssen, Jan J Kuiper, Wolf M MooijAbstract:Abstract. This study presents FABM-PCLake, a redesigned structure of the PCLake Aquatic ecosystem model, which we implemented in the Framework for Aquatic Biogeochemical Models (FABM). In contrast to the original model, which was designed for temperate, fully mixed freshwater lakes, the new FABM-PCLake represents an integrated Aquatic ecosystem model that can be linked with different hydrodynamic models and allows simulations of hydrodynamic and biogeochemical processes for zero-dimensional, one-dimensional as well as three-dimensional environments. FABM-PCLake describes interactions between multiple trophic levels, including piscivorous, zooplanktivorous and benthivorous fish, zooplankton, zoobenthos, three groups of phytoplankton and rooted macrophytes. The model also accounts for oxygen dynamics and nutrient cycling for nitrogen, phosphorus and silicon, both within the pelagic and benthic domains. FABM-PCLake includes a two-way communication between the biogeochemical processes and the physics, where some biogeochemical state variables (e.g., phytoplankton) influence light attenuation and thereby the spatial and temporal distributions of light and heat. At the same time, the physical environment, including water currents, light and temperature influence a wide range of biogeochemical processes. The model enables studies on ecosystem dynamics in physically heterogeneous environments (e.g., stratifying water bodies, and water bodies with horizontal gradients in physical and biogeochemical properties), and through FABM also enables data assimilation and multi-model ensemble simulations. Examples of potential new model applications include climate change impact studies and environmental impact assessment scenarios for temperate, sub-tropical and tropical lakes and reservoirs.
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fabm pclake linking Aquatic Ecology with hydrodynamics model description paper
Geoscientific Model Development, 2016Co-Authors: Karsten Bolding, Jorn Bruggeman, Erik Jeppesen, Morgens R Flindt, Luuk P A Van Gerven, Jan H Janse, Annette B G Janssen, Jan J Kuiper, Wolf M Mooij, Dennis TrolleAbstract:This study presents FABM-PCLake, a complete redesign of the PCLake Aquatic ecosystem model, which we implemented into the Framework for Aquatic Biogeochemical Models (FABM). In contrast to the original model, which was designed for temperate, fully mixed freshwater lakes, the new FABM-PCLake represents an integrated Aquatic ecosystem model that enables simulations of hydrodynamics and biogeochemical processes for zero dimensional, one-dimensional as well as three-dimensional heterogeneous environments. FABM-PCLake describes interactions between multiple trophic levels, including piscivorous, zooplanktivorous and benthivorous fish, zooplankton, zoobenthos, three groups of phytoplankton and rooted macrophytes. The model also accounts for oxygen dynamics and nutrient cycling for nitrogen, phosphorus and silicon, both within the pelagic and benthic domains. FABM-PCLake includes a two-way communication between the biogeochemical processes and the physics, where some biogeochemical state variables (e.g., phytoplankton) influence light attenuation and thereby the spatial and temporal distributions of light and heat. At the same time, the physical environment, including water currents, light and temperature influence a wide range of biogeochemical processes. The model enables studies on ecosystem dynamics in physically heterogeneous environments (e.g., stratifying water bodies, and water bodies with horizontal gradient in physical and biogeochemical properties), and through FABM also enables data assimilation and multi-model ensemble simulations. Examples of relevant model applications include climate change impact studies and environmental impact assessment scenarios for lakes and reservoirs worldwide.
Colin T Kremer - One of the best experts on this subject based on the ideXlab platform.
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realizing the potential of trait based Aquatic Ecology new tools and collaborative approaches
Limnology and Oceanography, 2017Co-Authors: Colin T Kremer, Alicia K Williams, Michael Finiguerra, Allison A Fong, Anne M Kellerman, Sara F Paver, Bradley B Tolar, Benjamin J ToscanoAbstract:Trait-based Ecology, which focuses on using the traits of species and individuals to understand Ecology (from populations to ecosystems), is becoming an increasingly productive and widely employed paradigm. To date, trait-based approaches have been used to study taxa from microbes to megafauna in every major area of Aquatic Ecology yielding exciting results. However, this promising field faces a number of significant obstacles, including: (1) identifying and measuring ecologically relevant traits, (2) integrating inter- and intra-specific trait variation, (3) detecting and quantifying trait correlations and trade-offs, and (4) accounting for the context dependency of traits. These issues are often particularly acute for specific taxa or systems. This paper highlights these looming challenges, as well as ways to address them. Proposed solutions center around using new technologies to collect trait data, coordinating research efforts, and curating and sharing data. Throughout, we take an interdisciplinary approach, sharing examples spanning a wide range of Aquatic taxa and systems. It is our hope that this paper will stimulate frank discussions and help the growing field of trait-based Aquatic Ecology maximize its potential.
Dorthe C Mullernavarra - One of the best experts on this subject based on the ideXlab platform.
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the role of highly unsaturated fatty acids in Aquatic foodweb processes
Freshwater Biology, 1997Co-Authors: Michael T. Brett, Dorthe C MullernavarraAbstract:1. Polyunsaturated fatty acids (PUFA) are almost exclusively synthesized by plants. Animals can convert from one form of PUFA to another through elongation and desaturation, but very few can synthesize PUFA de novo. PUFA play an important role in regulating cell membrane properties, serve as precursors for important animal hormones and are essential for animals. 2. In aquaculture studies, highly unsaturated fatty acids (HUFA), a subset of PUFA, have been found to be critical for maintaining high growth, survival and reproductive rates and high food conversion efficiencies for a wide variety of marine and freshwater organisms. 3. The plankton literature suggests high food-quality algae species are rich in HUFA and low food-quality algae are poor in HUFA. Adding semi-pure emulsions of HUFA to algae monocultures can markedly increase the growth rates of zooplankton feeding on these mixtures. 4. A study measuring zooplankton biomass accrual when feeding on natural phytoplankton found a strong correlation between phytoplankton HUFA (specifically eicosapentaenoic acid) content and herbivorous zooplankton production. 5. The Aquatic Ecology literature suggests that planktonic foodwebs with high HUFA content phytoplankton have high zooplankton to phytoplankton biomass ratios, while systems with low HUFA phytoplankton have low zooplankton biomass. Also, the seasonal succession of plankton in many temperate lakes follows patterns tied to phytoplankton HUFA content, with intense zooplankton grazing and ‘clear-water-phases’ characteristic of periods when the phytoplankton is dominated by HUFA-rich species. 6. Herbivorous zooplankton production is constrained by the zooplankton’s ability to ingest and digest phytoplankton. It is becoming increasingly clear, however, that much of the phytoplankton which is assimilated may be nutritionally inadequate. HUFA may be key nutritional constituents of zooplankton diets, and may determine energetic efficiency across the plant–animal interface, secondary production and the strength of trophic coupling in Aquatic pelagic foodwebs.