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Papers by karen Timmermann
Aquaculture Environment Interactions, Mar 30, 2023
Water Resources and Economics, 2020
Kari Eilola, Swedish Meteorological and Hydrological Institute Sven Källfelts gata 15, SE-426 71 ... more Kari Eilola, Swedish Meteorological and Hydrological Institute Sven Källfelts gata 15, SE-426 71 V Frölunda, Sweden Telephone +46(0)31 7518963 E-mail kari.eilola@smhi.se
Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi ©, 2020
Limnology and Oceanography, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Frontiers in Marine Science, 2020
Coastal seas are highly productive systems, providing an array of ecosystem services to humankind... more Coastal seas are highly productive systems, providing an array of ecosystem services to humankind, such as processing of nutrient effluents from land and climate regulation. However, coastal ecosystems are threatened by human-induced pressures such as climate change and eutrophication. In the coastal zone, the fluxes and transformations of nutrients and carbon sustaining coastal ecosystem functions and services are strongly regulated by benthic biological and chemical processes. Thus, to understand and quantify how coastal ecosystems respond to environmental change, mechanistic modeling of benthic biogeochemical processes is required. Here, we discuss the present model capabilities to quantitatively describe how benthic fauna drives nutrient and carbon processing in the coastal zone. There are a multitude of modeling approaches of different complexity, but a thorough mechanistic description of benthic-pelagic processes is still hampered by a fundamental lack of scientific understanding of the diverse interactions between the physical, chemical and biological processes that drive biogeochemical fluxes in the coastal zone. Especially shallow systems with long water residence times are sensitive to the activities of benthic organisms. Hence, including and improving the description of benthic biomass and metabolism in sediment diagenetic as well as ecosystem models for such systems is essential to increase our understanding of their response to environmental changes and the role of coastal sediments in nutrient and carbon cycling. Major challenges and research priorities are (1) to couple the dynamics of zoobenthic biomass and metabolism to sediment reactive-transport in models, (2) to test and validate model formulations against real-world data to better incorporate the context-dependency of processes in heterogeneous coastal areas in models and (3) to capture the role of stochastic events.
Journal of Marine Systems, 2012
ABSTRACT Nutrient loading of aquatic ecosystems results in more food for benthic macrofaunal comm... more ABSTRACT Nutrient loading of aquatic ecosystems results in more food for benthic macrofaunal communities but also increases the risk of hypoxia, resulting in a reduction or complete loss of benthic biomass. This study inves-tigates the interaction between eutrophication, hypoxia and benthic biomass with emphasis on the balance between gains and loss of benthic biomass due to changes in nutrient loadings. A physiological fauna model with 5 functional groups was linked to a 3D coupled hydrodynamic–ecological Baltic Sea model. Model results revealed that benthic biomass increased between 0 and 700% after re-oxygenating bottom wa-ters. Nutrient reduction scenarios indicated improved oxygen concentrations in bottom waters and de-creased sedimentation of organic matter up to 40% after a nutrient load reduction following the Baltic Sea Action Plan. The lower food supply to benthos reduced the macrofaunal biomass up to 35% especially in areas not currently affected by hypoxia, whereas benthic biomass increased up to 200% in areas affected by eutrophication-induced hypoxia. The expected changes in benthic biomass resulting from nutrient load re-ductions and subsequent reduced hypoxia may not only increase the food supply for benthivorous fish, but also significantly affect the biogeochemical functioning of the ecosystem.
Aquaculture Environment Interactions, Mar 30, 2023
Water Resources and Economics, 2020
Kari Eilola, Swedish Meteorological and Hydrological Institute Sven Källfelts gata 15, SE-426 71 ... more Kari Eilola, Swedish Meteorological and Hydrological Institute Sven Källfelts gata 15, SE-426 71 V Frölunda, Sweden Telephone +46(0)31 7518963 E-mail kari.eilola@smhi.se
Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi ©, 2020
Limnology and Oceanography, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Frontiers in Marine Science, 2020
Coastal seas are highly productive systems, providing an array of ecosystem services to humankind... more Coastal seas are highly productive systems, providing an array of ecosystem services to humankind, such as processing of nutrient effluents from land and climate regulation. However, coastal ecosystems are threatened by human-induced pressures such as climate change and eutrophication. In the coastal zone, the fluxes and transformations of nutrients and carbon sustaining coastal ecosystem functions and services are strongly regulated by benthic biological and chemical processes. Thus, to understand and quantify how coastal ecosystems respond to environmental change, mechanistic modeling of benthic biogeochemical processes is required. Here, we discuss the present model capabilities to quantitatively describe how benthic fauna drives nutrient and carbon processing in the coastal zone. There are a multitude of modeling approaches of different complexity, but a thorough mechanistic description of benthic-pelagic processes is still hampered by a fundamental lack of scientific understanding of the diverse interactions between the physical, chemical and biological processes that drive biogeochemical fluxes in the coastal zone. Especially shallow systems with long water residence times are sensitive to the activities of benthic organisms. Hence, including and improving the description of benthic biomass and metabolism in sediment diagenetic as well as ecosystem models for such systems is essential to increase our understanding of their response to environmental changes and the role of coastal sediments in nutrient and carbon cycling. Major challenges and research priorities are (1) to couple the dynamics of zoobenthic biomass and metabolism to sediment reactive-transport in models, (2) to test and validate model formulations against real-world data to better incorporate the context-dependency of processes in heterogeneous coastal areas in models and (3) to capture the role of stochastic events.
Journal of Marine Systems, 2012
ABSTRACT Nutrient loading of aquatic ecosystems results in more food for benthic macrofaunal comm... more ABSTRACT Nutrient loading of aquatic ecosystems results in more food for benthic macrofaunal communities but also increases the risk of hypoxia, resulting in a reduction or complete loss of benthic biomass. This study inves-tigates the interaction between eutrophication, hypoxia and benthic biomass with emphasis on the balance between gains and loss of benthic biomass due to changes in nutrient loadings. A physiological fauna model with 5 functional groups was linked to a 3D coupled hydrodynamic–ecological Baltic Sea model. Model results revealed that benthic biomass increased between 0 and 700% after re-oxygenating bottom wa-ters. Nutrient reduction scenarios indicated improved oxygen concentrations in bottom waters and de-creased sedimentation of organic matter up to 40% after a nutrient load reduction following the Baltic Sea Action Plan. The lower food supply to benthos reduced the macrofaunal biomass up to 35% especially in areas not currently affected by hypoxia, whereas benthic biomass increased up to 200% in areas affected by eutrophication-induced hypoxia. The expected changes in benthic biomass resulting from nutrient load re-ductions and subsequent reduced hypoxia may not only increase the food supply for benthivorous fish, but also significantly affect the biogeochemical functioning of the ecosystem.