The Eutrophication of the Baltic Sea has been Boosted and Perpetuated by a Major Internal Phosphorus Source

The phosphorus (P) concentration c1 in the surface layer of the Baltic proper in winter depends on the land-based P source LPS, and the ocean P source OPS, which are known. It also depends on the internal P source IPS from anoxic bottoms and the sum of internal and external P sinks TPsink, which are...

Full description

Bibliographic Details
Main Authors: Anders Stigebrandt, Ambjörn Andersson
Format: Article
Language:English
Published: Frontiers Media S.A. 2020-11-01
Series:Frontiers in Marine Science
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fmars.2020.572994/full
_version_ 1818405834403610624
author Anders Stigebrandt
Ambjörn Andersson
author_facet Anders Stigebrandt
Ambjörn Andersson
author_sort Anders Stigebrandt
collection DOAJ
description The phosphorus (P) concentration c1 in the surface layer of the Baltic proper in winter depends on the land-based P source LPS, and the ocean P source OPS, which are known. It also depends on the internal P source IPS from anoxic bottoms and the sum of internal and external P sinks TPsink, which are estimated in this paper. IPS is parameterized as fs·Aanox, where fs is the specific annual mass flux of P from anoxic sediments and Aanox is the area of anoxic bottoms, and TPsink is parameterized as c1·TRVF, where TRVF is the total removal volume flux. We use a time-dependent P budget model, and 47 years of observational data, and the method of least squares to determine the best estimates of the unknown parameters fs and TRVF. The result is TRVF = 3,000 km3 year−1 and fs = 1.22 tons P km−2 year−1. With these parameter values, the model gives a quite good description of the observed evolution of c1. The observed runaway evolution of c1, with increasing c1 since the 1980s although the land-based supply LPS has been halved, is well-described by the model. It is concluded that the internal P source IPS provides a positive feedback mechanism that has boosted and perpetuated the eutrophication of the Baltic proper and that IPS is the major driver of the Baltic Sea eutrophication since the late 1990s. It is suggested that measures to eliminate IPS should be included in the management strategy to reduce the eutrophication of the Baltic proper.
first_indexed 2024-12-14T09:02:21Z
format Article
id doaj.art-551dd54632c143abaee5bf585941b446
institution Directory Open Access Journal
issn 2296-7745
language English
last_indexed 2024-12-14T09:02:21Z
publishDate 2020-11-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Marine Science
spelling doaj.art-551dd54632c143abaee5bf585941b4462022-12-21T23:08:48ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452020-11-01710.3389/fmars.2020.572994572994The Eutrophication of the Baltic Sea has been Boosted and Perpetuated by a Major Internal Phosphorus SourceAnders StigebrandtAmbjörn AnderssonThe phosphorus (P) concentration c1 in the surface layer of the Baltic proper in winter depends on the land-based P source LPS, and the ocean P source OPS, which are known. It also depends on the internal P source IPS from anoxic bottoms and the sum of internal and external P sinks TPsink, which are estimated in this paper. IPS is parameterized as fs·Aanox, where fs is the specific annual mass flux of P from anoxic sediments and Aanox is the area of anoxic bottoms, and TPsink is parameterized as c1·TRVF, where TRVF is the total removal volume flux. We use a time-dependent P budget model, and 47 years of observational data, and the method of least squares to determine the best estimates of the unknown parameters fs and TRVF. The result is TRVF = 3,000 km3 year−1 and fs = 1.22 tons P km−2 year−1. With these parameter values, the model gives a quite good description of the observed evolution of c1. The observed runaway evolution of c1, with increasing c1 since the 1980s although the land-based supply LPS has been halved, is well-described by the model. It is concluded that the internal P source IPS provides a positive feedback mechanism that has boosted and perpetuated the eutrophication of the Baltic proper and that IPS is the major driver of the Baltic Sea eutrophication since the late 1990s. It is suggested that measures to eliminate IPS should be included in the management strategy to reduce the eutrophication of the Baltic proper.https://www.frontiersin.org/articles/10.3389/fmars.2020.572994/fulltipping pointBaltic properoxygenationrestorationenvironmental modelinginternal phosphorus source
spellingShingle Anders Stigebrandt
Ambjörn Andersson
The Eutrophication of the Baltic Sea has been Boosted and Perpetuated by a Major Internal Phosphorus Source
Frontiers in Marine Science
tipping point
Baltic proper
oxygenation
restoration
environmental modeling
internal phosphorus source
title The Eutrophication of the Baltic Sea has been Boosted and Perpetuated by a Major Internal Phosphorus Source
title_full The Eutrophication of the Baltic Sea has been Boosted and Perpetuated by a Major Internal Phosphorus Source
title_fullStr The Eutrophication of the Baltic Sea has been Boosted and Perpetuated by a Major Internal Phosphorus Source
title_full_unstemmed The Eutrophication of the Baltic Sea has been Boosted and Perpetuated by a Major Internal Phosphorus Source
title_short The Eutrophication of the Baltic Sea has been Boosted and Perpetuated by a Major Internal Phosphorus Source
title_sort eutrophication of the baltic sea has been boosted and perpetuated by a major internal phosphorus source
topic tipping point
Baltic proper
oxygenation
restoration
environmental modeling
internal phosphorus source
url https://www.frontiersin.org/articles/10.3389/fmars.2020.572994/full
work_keys_str_mv AT andersstigebrandt theeutrophicationofthebalticseahasbeenboostedandperpetuatedbyamajorinternalphosphorussource
AT ambjornandersson theeutrophicationofthebalticseahasbeenboostedandperpetuatedbyamajorinternalphosphorussource
AT andersstigebrandt eutrophicationofthebalticseahasbeenboostedandperpetuatedbyamajorinternalphosphorussource
AT ambjornandersson eutrophicationofthebalticseahasbeenboostedandperpetuatedbyamajorinternalphosphorussource