Ocean alkalinity enhancement impacts: regrowth of marine microalgae in alkaline mineral concentrations simulating the initial concentrations after ship-based dispersions
Increasing the marine carbon dioxide (CO 2 ) absorption capacity by adding alkaline minerals into the world's oceans is a promising marine carbon dioxide removal (mCDR) approach to increase the ocean's CO 2 storage potential and mitigate ocean acidification. Still, the biological impacts o...
Published in: | Biogeosciences |
---|---|
Main Authors: | , , , , |
Format: | Text |
Language: | English |
Published: |
2024
|
Subjects: | |
Online Access: | https://doi.org/10.5194/bg-21-3677-2024 https://bg.copernicus.org/articles/21/3677/2024/ |
id |
ftcopernicus:oai:publications.copernicus.org:bg114235 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:bg114235 2024-09-09T20:01:45+00:00 Ocean alkalinity enhancement impacts: regrowth of marine microalgae in alkaline mineral concentrations simulating the initial concentrations after ship-based dispersions Delacroix, Stephanie Nystuen, Tor Jensen Tobiesen, August E. Dessen King, Andrew L. Höglund, Erik 2024-08-22 application/pdf https://doi.org/10.5194/bg-21-3677-2024 https://bg.copernicus.org/articles/21/3677/2024/ eng eng doi:10.5194/bg-21-3677-2024 https://bg.copernicus.org/articles/21/3677/2024/ eISSN: 1726-4189 Text 2024 ftcopernicus https://doi.org/10.5194/bg-21-3677-2024 2024-08-28T05:24:22Z Increasing the marine carbon dioxide (CO 2 ) absorption capacity by adding alkaline minerals into the world's oceans is a promising marine carbon dioxide removal (mCDR) approach to increase the ocean's CO 2 storage potential and mitigate ocean acidification. Still, the biological impacts of dispersion of alkaline minerals need to be evaluated prior to its field deployment, especially the impacts of the initial discharge causing local and temporary extreme alkalinity/pH changes. In this study, the toxicity effect on marine microalgae of two commonly used alkaline minerals, calcium hydroxide (Ca(OH) 2 ) and magnesium hydroxide (Mg(OH) 2 ), was determined by adding the same equivalent molar concentration of hydroxyl ions. Cultures of marine green microalgae Tetraselmis suecica were exposed to Ca(OH) 2 or Mg(OH) 2 , in concentrations mimicking the initial high concentrations following a dispersion scenario from a ship. A short-term exposure with high-alkaline mineral concentration called “dispersion phase” was followed by a dilution step and a “regrowth” phase over 6 d. There was no detectable effect of Mg(OH) 2 treatment on algae growth either after the dispersion phase or during the regrowth phase, compared to control treatments. The Ca(OH) 2 treatment resulted in very few living algal cells after the dispersion phase, but a similar growth rate was observed during the regrowth phase as was for the Mg(OH) 2 and control treatments. Standardized whole effluent toxicity (WET) tests were carried out with a range of Mg(OH) 2 concentrations using a sensitive marine diatom, Skeletonema costatum , which confirmed the relatively low toxicity effect of Mg(OH) 2 . Similar biological effects were observed on natural microalgae assemblages from a local seawater source when applying the same Mg(OH) 2 concentration range and exposure time used in the WET tests. The results suggest that Mg(OH) 2 is relatively safe compared to Ca(OH) 2 with respect to marine microalgae. Text Ocean acidification Copernicus Publications: E-Journals Biogeosciences 21 16 3677 3690 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Increasing the marine carbon dioxide (CO 2 ) absorption capacity by adding alkaline minerals into the world's oceans is a promising marine carbon dioxide removal (mCDR) approach to increase the ocean's CO 2 storage potential and mitigate ocean acidification. Still, the biological impacts of dispersion of alkaline minerals need to be evaluated prior to its field deployment, especially the impacts of the initial discharge causing local and temporary extreme alkalinity/pH changes. In this study, the toxicity effect on marine microalgae of two commonly used alkaline minerals, calcium hydroxide (Ca(OH) 2 ) and magnesium hydroxide (Mg(OH) 2 ), was determined by adding the same equivalent molar concentration of hydroxyl ions. Cultures of marine green microalgae Tetraselmis suecica were exposed to Ca(OH) 2 or Mg(OH) 2 , in concentrations mimicking the initial high concentrations following a dispersion scenario from a ship. A short-term exposure with high-alkaline mineral concentration called “dispersion phase” was followed by a dilution step and a “regrowth” phase over 6 d. There was no detectable effect of Mg(OH) 2 treatment on algae growth either after the dispersion phase or during the regrowth phase, compared to control treatments. The Ca(OH) 2 treatment resulted in very few living algal cells after the dispersion phase, but a similar growth rate was observed during the regrowth phase as was for the Mg(OH) 2 and control treatments. Standardized whole effluent toxicity (WET) tests were carried out with a range of Mg(OH) 2 concentrations using a sensitive marine diatom, Skeletonema costatum , which confirmed the relatively low toxicity effect of Mg(OH) 2 . Similar biological effects were observed on natural microalgae assemblages from a local seawater source when applying the same Mg(OH) 2 concentration range and exposure time used in the WET tests. The results suggest that Mg(OH) 2 is relatively safe compared to Ca(OH) 2 with respect to marine microalgae. |
format |
Text |
author |
Delacroix, Stephanie Nystuen, Tor Jensen Tobiesen, August E. Dessen King, Andrew L. Höglund, Erik |
spellingShingle |
Delacroix, Stephanie Nystuen, Tor Jensen Tobiesen, August E. Dessen King, Andrew L. Höglund, Erik Ocean alkalinity enhancement impacts: regrowth of marine microalgae in alkaline mineral concentrations simulating the initial concentrations after ship-based dispersions |
author_facet |
Delacroix, Stephanie Nystuen, Tor Jensen Tobiesen, August E. Dessen King, Andrew L. Höglund, Erik |
author_sort |
Delacroix, Stephanie |
title |
Ocean alkalinity enhancement impacts: regrowth of marine microalgae in alkaline mineral concentrations simulating the initial concentrations after ship-based dispersions |
title_short |
Ocean alkalinity enhancement impacts: regrowth of marine microalgae in alkaline mineral concentrations simulating the initial concentrations after ship-based dispersions |
title_full |
Ocean alkalinity enhancement impacts: regrowth of marine microalgae in alkaline mineral concentrations simulating the initial concentrations after ship-based dispersions |
title_fullStr |
Ocean alkalinity enhancement impacts: regrowth of marine microalgae in alkaline mineral concentrations simulating the initial concentrations after ship-based dispersions |
title_full_unstemmed |
Ocean alkalinity enhancement impacts: regrowth of marine microalgae in alkaline mineral concentrations simulating the initial concentrations after ship-based dispersions |
title_sort |
ocean alkalinity enhancement impacts: regrowth of marine microalgae in alkaline mineral concentrations simulating the initial concentrations after ship-based dispersions |
publishDate |
2024 |
url |
https://doi.org/10.5194/bg-21-3677-2024 https://bg.copernicus.org/articles/21/3677/2024/ |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-21-3677-2024 https://bg.copernicus.org/articles/21/3677/2024/ |
op_doi |
https://doi.org/10.5194/bg-21-3677-2024 |
container_title |
Biogeosciences |
container_volume |
21 |
container_issue |
16 |
container_start_page |
3677 |
op_container_end_page |
3690 |
_version_ |
1809933647856271360 |