mCDR Marine carbon dioxide removal (mCDR) technologies are being developed to remove excess carbon from ocean and coastal waters. MARCO Coastal Carbon Collaborative work group Coupling Desalination with Novel mCDR Membranes Data Requirements for Quantifying Natural Variability and the Background Ocean Carbon Sink in mCDR Models Assessing the Laboratory and Field Responses of Diatoms and Coccolithophores to Ocean Alkalinity Enhancement Developing a Coupled Benthic-Pelagic Biogeochemical Model to Evaluate the Effectiveness of mCDR Interventions Quantifying the Efficacy of Wastewater Alkalinity Enhancement on mCDR and Acidification Mitigation in a Large Estuary Determining the Influence of Ocean Alkalinity Enhancement on Foraminifera Calcification, Distribution, and CaCO3 Production Tidal wetlands as a low pH environment for accelerated and scalable olivine dissolution Assessing Carbon Dioxide Removal and Ecosystem Response for an Ocean Alkalinity Enhancement Field Trial Engaging U.S. Commercial Fishing Community to Develop Recommendations for Fishery-Sensitive mCDR Governance, Collaborative Research and Monitoring, and Outreach to Fishing Communities