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PERSPECTIVE article

Front. Clim.

Sec. Carbon Dioxide Removal

Volume 7 - 2025 | doi: 10.3389/fclim.2025.1528951

This article is part of the Research TopicEnvironmental Engineering Perspectives on Ocean-Based Carbon Dioxide RemovalView all 3 articles

Removal of dissolved inorganic carbon from seawater for climate change mitigation – understanding the potential marine ecosystem impacts

Provisionally accepted
  • 1Plymouth Marine Laboratory, Plymouth, United Kingdom
  • 2University of Exeter, Exeter, England, United Kingdom

The final, formatted version of the article will be published soon.

Electrochemical technology can be used to remove inorganic carbon from seawater and facilitate the removal of carbon dioxide (CO2) from the atmosphere. Electrochemical ‘Direct Ocean Carbon Capture and Storage’ (DOCCS) is a marine carbon dioxide removal (mCDR) method that removes atmospheric CO2 by releasing low-carbon seawater into the surface ocean, where it re-equilibrates with the atmosphere and stores atmospheric CO2. At the point of release, DOCCS discharge has low concentrations of dissolved inorganic carbon (DIC) and high pH, potentially causing unintended marine environmental impacts; however, its chemistry moves progressively towards that of ambient seawater as it dilutes and re-equilibrates with the atmosphere. To date, there are no published studies that investigate the impact of DOCCS discharge on marine ecosystems. Research from relevant analogues, where biological responses to low-DIC and/or high-pH seawater are investigated, provides some insight into potential DOCCS impacts. Despite this, significant evidence gaps remain. These evidence gaps are discussed alongside DOCCS-specific recommendations for future environmental impact research. Understanding the potential risks/benefits to marine ecosystems from discharge of low-DIC and high-pH seawater is critical to: i) support licensing applications; ii) develop any necessary mitigating actions; iii) determine the net benefit of mCDR approaches; and iv) stimulate informed public discourse about the acceptability of such approaches.

Keywords: Marine environmental impacts, Carbon dioxide removal, Direct Ocean Carbon Capture and Storage, DOCCs, MCDR, marine carbon dioxide removal, High pH

Received: 15 Nov 2024; Accepted: 09 Jul 2025.

Copyright: © 2025 Hooper, Findlay, Bell, Wilson and Halloran. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Guy Hooper, Plymouth Marine Laboratory, Plymouth, United Kingdom
Paul Halloran, University of Exeter, Exeter, EX4 4PY, England, United Kingdom

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