Per O. J. Hall

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We have combined several different methodologies to quantify rates of organic carbon mineralization by the various electron acceptors in sediments from the coast of Denmark and Norway. Rates of NH4+ and Sigma CO2 liberation sediment incubations were used with O2 penetration depths to conclude that O2 respiration accounted for only between 3.6-17.4% of the(More)
The external phosphorus (P) loading has been halved, but the P content in the water column and the area of anoxic bottoms in Baltic proper has increased during the last 30 years. This can be explained by a temporary internal source of dissolved inorganic phosphorus (DIP) that is turned on when the water above the bottom sediment becomes anoxic. A(More)
Oxygen-depleted bodies of water are becoming increasingly common in marine ecosystems. Solutions to reverse this trend are needed and under development, for example, by the Baltic deep-water OXygenation (BOX) project. In the framework of this project, the Swedish Byfjord was chosen for a pilot study, investigating the effects of an engineered oxygenation on(More)
In a 2.5-year-long environmental engineering experiment in the By Fjord, surface water was pumped into the deepwater where the frequency of deepwater renewals increased by a factor of 10. During the experiment, the deepwater became long-term oxic, and nitrate became the dominating dissolved inorganic nitrogen component. The amount of phosphate in the water(More)
<lb>The SEGUE-project assembled and analysed new information about the eutrophying effects of nutrient loading<lb>and the biogeochemical processes which affect nutrient cycling in the Gulf of Finland and the Archipelago Sea.<lb>The project also studied how political decisions and policies concerning water protection affect the state of the<lb>Gulf. In(More)
Citation: Sommer S, Clemens D, Yücel M, Pfannkuche O, Hall POJ, Almroth-Rosell E, Schulz-Vogt HN and Dale AW (2017) Major Bottom Water Ventilation Events Do Not Significantly Reduce Basin-Wide Benthic N and P Release in the Eastern Gotland Basin (Baltic Sea). Front. Mar. Sci. 4:18. doi: 10.3389/fmars.2017.00018 Major Bottom Water Ventilation Events Do Not(More)
Pore water and solid phase distributions of C, N, P and Si in sediments of the Arctic Ocean (Svalbard area) have been investigated. Concentrations of organic carbon (Corg) in the solid phase of the sediment varied from 1.3 to 2.8% (mean 1.9%), with highest concentrations found at shallow stations south/southwest of Svalbard. Relatively low concentrations(More)
Citation: Hall POJ, Almroth Rosell E, Bonaglia S, Dale AW, Hylén A, Kononets M, Nilsson M, Sommer S, van de Velde S and Viktorsson L (2017) Influence of Natural Oxygenation of Baltic Proper Deep Water on Benthic Recycling and Removal of Phosphorus, Nitrogen, Silicon and Carbon. Front. Mar. Sci. 4:27. doi: 10.3389/fmars.2017.00027 Influence of Natural(More)
Sensor technology is rapidly advancing, enabling smaller and less expensive instruments to monitor Earth’s environment. It is expected that many more kinds and quantities of networked environmental sensors will be deployed in coming years. This work presents an approach for the smart configuration and integration of marine sensors into an interoperable(More)
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