| 1. |
- Danielsson, Åsa, et al.
(författare)
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Effects of re-oxygenation and bioturbation by the polychaete Marenzelleria arctia on phosphorus, iron and manganese dynamics in Baltic Sea sediments
- 2018
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Ingår i: Boreal environment research. - : FINNISH ENVIRONMENT INST. - 1239-6095 .- 1797-2469. ; 23, s. 15-28
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Tidskriftsartikel (refereegranskat)abstract
- Sediments underlying hypoxic or anoxic water bodies constitute a net source of phosphorus to the bottom water. This source has the potential to enhance eutrophication. Benthic fluxes of dissolved phosphorus, iron and manganese were measured from hypoxic, normoxic, and normoxic bioturbated by the invasive polychaete Marenzelleria arctia sediment in a mesocosm experiment. The highest benthic phosphorus efflux was detected in mesocosms with the hypoxic treatment. Normoxic, bioturbated sediments led to weaker retention of phosphorus compared to oxic, defaunated sediments. Both iron and manganese fluxes increased under bioturbated conditions compared to defaunated sediments. This study shows that re-oxygenation of previously anoxic coastal sediments enhance phosphorus retention in the sediments. Colonisation by M. arctia induce strong mobilisation of iron and manganese due to its intense bioirrigation, which facilitates organic matter degradation and decreases the phosphorus retention by metal oxides in sediment.
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| 2. |
- Edgren, Lars, et al.
(författare)
-
Birgitta Odén, 1921-2016
- 2016
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Ingår i: Vetenskapssocieteten i Lund. Årsbok 2016. - 0349-053X. - 9789198055160
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Bokkapitel (populärvet., debatt m.m.)
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| 3. |
- Stigebrandt, Anders, 1942, et al.
(författare)
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An Experiment with Forced Oxygenation of the Deepwater of the Anoxic By Fjord, Western Sweden
- 2015
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Ingår i: Ambio. - : Springer Netherlands. - 0044-7447 .- 1654-7209. ; 44:1, s. 42-54
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Tidskriftsartikel (refereegranskat)abstract
- 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 column decreased by a factor of 5 due to the increase in flushing and reduction in the leakage of phosphate from the sediments when the sediment surface became oxidized. Oxygenation of the sediments did not increase the leakage of toxic metals and organic pollutants. The bacterial community was the first to show changes after the oxygenation, with aerobic bacteria also thriving in the deepwater. The earlier azoic deepwater bottom sediments were colonized by animals. No structural difference between the phytoplankton communities in the By Fjord and the adjacent Havsten Fjord, with oxygenated deepwater, could be detected during the experiment.
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