Preprints
https://doi.org/10.1101/2023.04.08.536121
https://doi.org/10.1101/2023.04.08.536121
10 May 2023
 | 10 May 2023

Responses of globally important phytoplankton groups to olivine dissolution products and implications for carbon dioxide removal via ocean alkalinity enhancement

David A. Hutchins, Fei-Xue Fu, Shun-Chung Yang, Seth G. John, Stephen J. Romaniello, M. Grace Andrews, and Nathan G. Walworth

Abstract. Anthropogenic greenhouse gas emissions are leading to global temperature increases, ocean acidification, and significant ecosystem impacts. Given current emissions trajectories, the IPCC calls for both the rapid abatement of CO2 emissions and development of carbon dioxide removal (CDR) strategies that can address legacy emissions and difficult to abate emissions sources. These CDR methods must efficiently and safely sequester gigatons of atmospheric CO2. Coastal Enhanced Weathering (CEW) via the addition of the common mineral olivine to coastal waters is one promising approach to enhance ocean alkalinity for large-scale CDR. As olivine weathers, it releases several biologically active dissolution products, including alkalinity, trace metals, and the nutrient silicate. Released trace metals can serve as micronutrients but may also be toxic at high concentrations to marine biota including phytoplankton that lie at the base of marine food webs. We grew several globally important phytoplankton functional groups under elevated concentrations of olivine dissolution products using a synthetic olivine leachate (OL) based on olivine elemental composition, and monitored their physiological and biogeochemical responses. This allowed us to determine physiological impacts and thresholds at elevated olivine leachate concentrations, in addition to individual effects of specific constituents. We found both positive and neutral responses but no evident toxic effects for two silicifying diatoms, a calcifying coccolithophore, and three cyanobacteria. In both single and competitive co-cultures, silicifiers and calcifiers benefited from olivine dissolution products like iron and silicate or enhanced alkalinity, respectively. The non-N2-fixing picocyanobacterium could use synthetic olivine-derived iron for growth, while N2-fixing cyanobacteria could not. However, other trace metals like nickel and cobalt supported cyanobacterial growth across both groups. Growth benefits to particular phytoplankton groups in situ will depend on species-specific responses and ambient concentrations of other required nutrients. Results suggest olivine dissolution products appear unlikely to cause negative effects for marine phytoplankton, even at high concentrations, and may support growth of particular taxa under some conditions. Future studies can shed light on long-term evolutionary responses to olivine exposure, and on the potential effects that marine microbes may in turn have on olivine dissolution rates and regional biogeochemistry.

Journal article(s) based on this preprint

27 Nov 2023
| Highlight paper
Responses of globally important phytoplankton species to olivine dissolution products and implications for carbon dioxide removal via ocean alkalinity enhancement
David A. Hutchins, Fei-Xue Fu, Shun-Chung Yang, Seth G. John, Stephen J. Romaniello, M. Grace Andrews, and Nathan G. Walworth
Biogeosciences, 20, 4669–4682, https://doi.org/10.5194/bg-20-4669-2023,https://doi.org/10.5194/bg-20-4669-2023, 2023
Short summary Co-editor-in-chief

David A. Hutchins et al.

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2023-930', Lennart Bach, 21 Jun 2023
    • AC1: 'Reply on RC1', Nathan Walworth, 23 Jul 2023
  • RC2: 'Comment on egusphere-2023-930', Anonymous Referee #2, 28 Jun 2023
    • AC2: 'Reply on RC2', Nathan Walworth, 23 Jul 2023

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2023-930', Lennart Bach, 21 Jun 2023
    • AC1: 'Reply on RC1', Nathan Walworth, 23 Jul 2023
  • RC2: 'Comment on egusphere-2023-930', Anonymous Referee #2, 28 Jun 2023
    • AC2: 'Reply on RC2', Nathan Walworth, 23 Jul 2023

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload
ED: Publish subject to minor revisions (review by editor) (21 Aug 2023) by Patricia Grasse
ED: Publish subject to minor revisions (review by editor) (21 Aug 2023) by Tyler Cyronak (Co-editor-in-chief)
AR by Nathan Walworth on behalf of the Authors (23 Aug 2023)  Author's response   Author's tracked changes   Manuscript 
ED: Referee Nomination & Report Request started (14 Sep 2023) by Patricia Grasse
RR by Anonymous Referee #2 (17 Sep 2023)
RR by Lennart Bach (11 Oct 2023)
ED: Publish as is (11 Oct 2023) by Patricia Grasse
ED: Publish as is (11 Oct 2023) by Tyler Cyronak (Co-editor-in-chief)
AR by Nathan Walworth on behalf of the Authors (17 Oct 2023)  Manuscript 

Journal article(s) based on this preprint

27 Nov 2023
| Highlight paper
Responses of globally important phytoplankton species to olivine dissolution products and implications for carbon dioxide removal via ocean alkalinity enhancement
David A. Hutchins, Fei-Xue Fu, Shun-Chung Yang, Seth G. John, Stephen J. Romaniello, M. Grace Andrews, and Nathan G. Walworth
Biogeosciences, 20, 4669–4682, https://doi.org/10.5194/bg-20-4669-2023,https://doi.org/10.5194/bg-20-4669-2023, 2023
Short summary Co-editor-in-chief

David A. Hutchins et al.

David A. Hutchins et al.

Viewed

Since the preprint corresponding to this journal article was posted outside of Copernicus Publications, the preprint-related metrics are limited to HTML views.

Total article views: 603 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
603 0 0 603 4 7
  • HTML: 603
  • PDF: 0
  • XML: 0
  • Total: 603
  • BibTeX: 4
  • EndNote: 7
Views and downloads (calculated since 10 May 2023)
Cumulative views and downloads (calculated since 10 May 2023)

Viewed (geographical distribution)

Since the preprint corresponding to this journal article was posted outside of Copernicus Publications, the preprint-related metrics are limited to HTML views.

Total article views: 599 (including HTML, PDF, and XML) Thereof 599 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Latest update: 06 Dec 2023
Download

The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

This important study evaluates the impacts of enhanced olivine weathering on globally relevant phytoplankton species. Results from the study indicate that olivine dissolution products are unlikely to negatively impact the six phytoplankton species tested and may even enhance growth under certain conditions. Studies examining the safety of ocean alkalinity enhancement are urgently needed as interest in deploying this strategy for carbon dioxide removal is increasing.
Short summary
The IPCC has called for the rapid development of CO2 removal strategies. Coastal Enhanced Weathering (CEW) via the addition of the common mineral olivine to coastal waters is one promising approach. Olivine releases trace metals that can affect organisms like phytoplankton. We exposed phytoplankton to olivine products and observed no negative effects. These data indicate that CEW with olivine will likely not be harmful to phytoplankton, suggesting it to be safe for them at large scales.