Long-Term and Seasonal Trends in Estuarine and Coastal Carbonate Systems
Coastal pH and total alkalinity are regulated by a diverse range of local processes superimposed on global trends of warming and ocean acidification, yet few studies have investigated the relative importance of different processes for coastal acidification. We describe long-term (1972-2016) and seas...
Published in: | Global Biogeochemical Cycles |
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Language: | English |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/32ef5d49-2454-47dd-9654-1d4bdfaa874d 2024-02-11T10:07:29+01:00 Long-Term and Seasonal Trends in Estuarine and Coastal Carbonate Systems Carstensen, Jacob Chierici, Melissa Gustafsson, Bo G. Gustafsson, Erik 2018-03 https://pure.au.dk/portal/en/publications/32ef5d49-2454-47dd-9654-1d4bdfaa874d https://doi.org/10.1002/2017GB005781 eng eng https://pure.au.dk/portal/en/publications/32ef5d49-2454-47dd-9654-1d4bdfaa874d info:eu-repo/semantics/restrictedAccess Carstensen , J , Chierici , M , Gustafsson , B G & Gustafsson , E 2018 , ' Long-Term and Seasonal Trends in Estuarine and Coastal Carbonate Systems ' , Global Biogeochemical Cycles , vol. 32 , no. 3 , pp. 497-513 . https://doi.org/10.1002/2017GB005781 acidification eutrophication global warming alkalinity estuarine mixing OCEAN ACIDIFICATION BALTIC SEA BIOGEOCHEMICAL PROCESSES DANISH ESTUARIES TOTAL ALKALINITY CHESAPEAKE BAY SEAWATER WATERS PH article 2018 ftuniaarhuspubl https://doi.org/10.1002/2017GB005781 2024-01-24T23:59:26Z Coastal pH and total alkalinity are regulated by a diverse range of local processes superimposed on global trends of warming and ocean acidification, yet few studies have investigated the relative importance of different processes for coastal acidification. We describe long-term (1972-2016) and seasonal trends in the carbonate system of three Danish coastal systems demonstrating that hydrological modification, changes in nutrient inputs from land, and presence/absence of calcifiers can drastically alter carbonate chemistry. Total alkalinity was mainly governed by conservative mixing of freshwater (0.73-5.17mmolkg(-1)) with outer boundary concentrations (similar to 2-2.4mmolkg(-1)), modulated seasonally and spatially (similar to 0.1-0.2mmolkg(-1)) by calcifiers. Nitrate assimilation by primary production, denitrification, and sulfate reduction increased total alkalinity by almost 0.6mmolkg(-1) in the most eutrophic system during a period without calcifiers. Trends in pH ranged from -0.0088year(-1) to 0.021year(-1), the more extreme of these mainly driven by salinity changes in a sluice-controlled lagoon. Temperature increased 0.05 degrees Cyr(-1) across all three systems, which directly accounted for a pH decrease of 0.0008year(-1). Accounting for mixing, salinity, and temperature effects on dissociation and solubility constants, the resulting pH decline (0.0040year(-1)) was about twice the ocean trend, emphasizing the effect of nutrient management on primary production and coastal acidification. Coastal pCO(2) increased similar to 4 times more rapidly than ocean rates, enhancing CO2 emissions to the atmosphere. Indeed, coastal systems undergo more drastic changes than the ocean and coastal acidification trends are substantially enhanced from nutrient reductions to address coastal eutrophication. Article in Journal/Newspaper Ocean acidification Aarhus University: Research Global Biogeochemical Cycles 32 3 497 513 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
acidification eutrophication global warming alkalinity estuarine mixing OCEAN ACIDIFICATION BALTIC SEA BIOGEOCHEMICAL PROCESSES DANISH ESTUARIES TOTAL ALKALINITY CHESAPEAKE BAY SEAWATER WATERS PH |
spellingShingle |
acidification eutrophication global warming alkalinity estuarine mixing OCEAN ACIDIFICATION BALTIC SEA BIOGEOCHEMICAL PROCESSES DANISH ESTUARIES TOTAL ALKALINITY CHESAPEAKE BAY SEAWATER WATERS PH Carstensen, Jacob Chierici, Melissa Gustafsson, Bo G. Gustafsson, Erik Long-Term and Seasonal Trends in Estuarine and Coastal Carbonate Systems |
topic_facet |
acidification eutrophication global warming alkalinity estuarine mixing OCEAN ACIDIFICATION BALTIC SEA BIOGEOCHEMICAL PROCESSES DANISH ESTUARIES TOTAL ALKALINITY CHESAPEAKE BAY SEAWATER WATERS PH |
description |
Coastal pH and total alkalinity are regulated by a diverse range of local processes superimposed on global trends of warming and ocean acidification, yet few studies have investigated the relative importance of different processes for coastal acidification. We describe long-term (1972-2016) and seasonal trends in the carbonate system of three Danish coastal systems demonstrating that hydrological modification, changes in nutrient inputs from land, and presence/absence of calcifiers can drastically alter carbonate chemistry. Total alkalinity was mainly governed by conservative mixing of freshwater (0.73-5.17mmolkg(-1)) with outer boundary concentrations (similar to 2-2.4mmolkg(-1)), modulated seasonally and spatially (similar to 0.1-0.2mmolkg(-1)) by calcifiers. Nitrate assimilation by primary production, denitrification, and sulfate reduction increased total alkalinity by almost 0.6mmolkg(-1) in the most eutrophic system during a period without calcifiers. Trends in pH ranged from -0.0088year(-1) to 0.021year(-1), the more extreme of these mainly driven by salinity changes in a sluice-controlled lagoon. Temperature increased 0.05 degrees Cyr(-1) across all three systems, which directly accounted for a pH decrease of 0.0008year(-1). Accounting for mixing, salinity, and temperature effects on dissociation and solubility constants, the resulting pH decline (0.0040year(-1)) was about twice the ocean trend, emphasizing the effect of nutrient management on primary production and coastal acidification. Coastal pCO(2) increased similar to 4 times more rapidly than ocean rates, enhancing CO2 emissions to the atmosphere. Indeed, coastal systems undergo more drastic changes than the ocean and coastal acidification trends are substantially enhanced from nutrient reductions to address coastal eutrophication. |
format |
Article in Journal/Newspaper |
author |
Carstensen, Jacob Chierici, Melissa Gustafsson, Bo G. Gustafsson, Erik |
author_facet |
Carstensen, Jacob Chierici, Melissa Gustafsson, Bo G. Gustafsson, Erik |
author_sort |
Carstensen, Jacob |
title |
Long-Term and Seasonal Trends in Estuarine and Coastal Carbonate Systems |
title_short |
Long-Term and Seasonal Trends in Estuarine and Coastal Carbonate Systems |
title_full |
Long-Term and Seasonal Trends in Estuarine and Coastal Carbonate Systems |
title_fullStr |
Long-Term and Seasonal Trends in Estuarine and Coastal Carbonate Systems |
title_full_unstemmed |
Long-Term and Seasonal Trends in Estuarine and Coastal Carbonate Systems |
title_sort |
long-term and seasonal trends in estuarine and coastal carbonate systems |
publishDate |
2018 |
url |
https://pure.au.dk/portal/en/publications/32ef5d49-2454-47dd-9654-1d4bdfaa874d https://doi.org/10.1002/2017GB005781 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_source |
Carstensen , J , Chierici , M , Gustafsson , B G & Gustafsson , E 2018 , ' Long-Term and Seasonal Trends in Estuarine and Coastal Carbonate Systems ' , Global Biogeochemical Cycles , vol. 32 , no. 3 , pp. 497-513 . https://doi.org/10.1002/2017GB005781 |
op_relation |
https://pure.au.dk/portal/en/publications/32ef5d49-2454-47dd-9654-1d4bdfaa874d |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1002/2017GB005781 |
container_title |
Global Biogeochemical Cycles |
container_volume |
32 |
container_issue |
3 |
container_start_page |
497 |
op_container_end_page |
513 |
_version_ |
1790606072690507776 |