Contrasting CO2 dynamics in seagrass meadows between organic carbon (OC)-rich reef and OC-poor terrestrial sediments: Implications for enhanced alkalinity production

This dataset covers the carbonate chemistry of seawater and porewater, sediment carbon content, and benthic alkalinity fluxes and carbon dioxide removal (CDR) in two distinct seagrass meadows: one situated in organic carbon (OC)–rich reef sediments and the other in OC–poor terrestrial sediments. Seawater carbonate chemistry parameters include temperature, salinity, pH, pCO2, dissolved inorganic carbon (DIC), total alkalinity (TA), bicarbonate (HCO3-), carbonate (CO32-), and aragonite saturation state. Porewater parameters include pH, DIC, TA, pCO2, aragonite saturation state, and calcium ion concentration. Sediment characterization covers total organic carbon (TOC), total inorganic carbon (TIC), and total nitrogen (TN). The benthic flux data include measurements taken during the daytime, nighttime, daily, and annually. The carbon dioxide removal capacity of seagrass was calculated from the measured total alkalinity., A. Sample collection
Seawater samples for TA, DIC, and pH analyses were collected at specific intervals. At the DS site, samples were taken at 06:00, 12:00, and 18:00 daily, while at the KT site, samples were collected at 4-hour intervals. Discrete seawater samples were obtained using a 9-L Nalgene™ HDPE carboy. Within 30 minutes of collection, the seawater samples were transferred into pre-cleaned 350-mL borosilicate bottles upon arrival at the laboratory in Dongsha or Kenting. To arrest biological activity, each sample received an injection of 200 μL of saturated HgCl2 solution, after which they were sealed and transported to the laboratory at the National Taiwan Ocean University. Subsequently, these samples underwent analysis for DIC, TA, and pH measurements.
Porewater samples were acquired using porewater wells, following a modified methodology described by Falter and Sansone (2000). At various sediment depths (2, 4, 6, 8, 12, 16, and 20 cm), 25 mL of pore water was extracted from e..., , GENERAL INFORMATION

1. TITLE OF DATASET: Contrasting CO2 Dynamics in Seagrass Meadows between Organic Carbon (OC)-Rich Reef and OC-Poor Terrestrial Sediments: Implications for Enhanced Alkalinity Production
2. GEOGRAPHICAL LOCATION OF DATA COLLECTION: Dongsha Island (DS), Taiwan, and Kenting (KT), Taiwan
3. FUNDING INFORMATION
Funding Agency: National Science and Technology Council (NSTC)
Funding No.: #112-2611-M-019 -005 and #112-2119-M-019 -008
4. CITATION OF THIS DATA: Chou, W-C, L.-F. Fan, M. B. Natividad, J.-J. Chen, Z.-W. Tang, H.-F. Chen, P.-C. Chen, E.-C. Kong, Y.-Y. Shih, W.-J. Huang, C.-C. Hung. 2024. Contrasting CO2 Dynamics in Seagrass Meadows between Organic Carbon (OC)-Rich Reef and OC-Poor Terrestrial Sediments: Implications for Enhanced Alkalinity Production.
5. DATA AND FILE OVERVIEW
**A. DS-KT_Water.csv**

Seawater carbonate chemistry parameters include temperature, salinity, pH, pCO2, dissolved inorganic carbon(DIC), total alkalinity (TA), bicarbonate (H...,