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Silicon isotope enr...
Silicon isotope enrichment in diatoms during nutrient-limited bloomsin a eutrophied river system
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- Sun, Xiaole, 1983- (författare)
- Stockholms universitet,Institutionen för geologiska vetenskaper
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- Anersson, Per (författare)
- Naturhistoriska riksmuseet, Laboratoriet för isotopgeologi
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- Humborg, Christoph (författare)
- Stockholms universitet,Institutionen för tillämpad miljövetenskap (ITM)
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visa fler...
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- Pastuszak, Marianna (författare)
- Department of Fisheries Oceanography and Marine Ecology, Sea Fisheries Institute, Gdynia, Poland
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- Mörth, Carl-Magnus (författare)
- Stockholms universitet,Institutionen för geologiska vetenskaper
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visa färre...
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(creator_code:org_t)
- Engelska.
- Relaterad länk:
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https://urn.kb.se/re...
Abstract
Ämnesord
Stäng
- We examined the Si isotope fractionation in diatoms by following a massive nutrient limited diatom bloom from a eutrophied natural system. We hypothesized that the Si isotope fractionation should be larger in comparison to observations in less nutrient rich environments. The Oder River, which is a eutrophied river draining the western half of Poland and entering the southern Baltic Sea, shows that a diatom bloom may cause extreme Si isotope fractionation. The rapid nutrient depletion and fast biogenic silica (BSi) increase observed during the spring bloom suggests a Rayleigh behavior for a closed system for dissolved Si (DSi) and BSi in the river at certain time scales. An enrichment factor (ε) of up to -1.6‰ is found based on observations between April and June, 2004. A very high δ30Si value of up to +3.05‰ is measured in diatoms. This is about 2 times higher than previously recorded δ30Si in freshwater diatoms. The Rayleigh model used to predict the δ30Si values of DSi suggests that the initial value before the start of the diatom bloom is close to +2‰. This indicates that there is a biological control of the Si isotope compositions entering the river, probably caused by Si isotope fractionation during uptake of Si in phytoliths. Clearly, eutrophied rivers with enhanced diatom blooms deliver 30Si-enriched DSi and BSi to the coastal ocean, which can be used to trace the biogeochemistry of DSi/BSi in estuaries.
Ämnesord
- NATURVETENSKAP -- Geovetenskap och miljövetenskap -- Geokemi (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences -- Geochemistry (hsv//eng)
Nyckelord
- geokemi
- Geochemistry
Publikations- och innehållstyp
- vet (ämneskategori)
- ovr (ämneskategori)