Acidification signals in estuarine sediment cores

The hypothesis that estuarine sediment cores contain signals which can be used to reconstruct shifts in the concentration of riverine humic matter (HM) and dissolved aluminum (Al) during acidification is examined. Dated sediment cores from Topdal Fjord (southern Norway) were analyzed for humic matte...

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Bibliographic Details
Published in:Limnology and Oceanography
Main Author: Egeberg, Per Kristian
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 1995
Subjects:
Online Access:http://dx.doi.org/10.4319/lo.1995.40.8.1438
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.1995.40.8.1438
https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1995.40.8.1438
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Summary:The hypothesis that estuarine sediment cores contain signals which can be used to reconstruct shifts in the concentration of riverine humic matter (HM) and dissolved aluminum (Al) during acidification is examined. Dated sediment cores from Topdal Fjord (southern Norway) were analyzed for humic matter and alkaline extractable Al. The proportions of riverine and marine HM were estimated from carbon‐to‐nitrogen ratios (C: N). The results agree qualitatively and quantitatively with predictions based on Al and HM behavior in estuaries and the suspected effect of acidification on the concentration of these parameters. The doubling in the concentration of riverine Al and 50% reduction in riverine HM in sediment cores from the Topdal estuary coincide with an abrupt increase in the proportion of Topdal River discharge originating from areas in which the critical loads of acidity have been exceeded by sulfur deposition. HM started to decrease and Al started to increase concurrently with declining catches of Atlantic salmon around a . d . 1900.