Sediment core dating to estimate carbon burial rates below seaweed farms (original) (raw)

Sediment cores were collected below seaweed farms between October 2020 and October 2021, in order to estimate the carbon burial rates and to compare them to reference sediments beyond the farm and/or prior to the farm operation. Sampling sites represented a total of 20 farms located in 11 different countries distributed globally, including the Americas, Europe, Africa and Asia. The majority of cores were taken manually by divers in shallow waters at <10 m depth. The sampling strategy consisted in collecting 3 cores within the farm area and 2 cores beyond it, as reference sites, which yielded a total of 108 cores. Cores were sliced at 0.5 cm, 1 cm and 2 cm thickness and analyzed for Pb-210, Ra-226, organic carbon and delta C-13. Pb-210 and Ra-226 were used to estimate the excess lead and to model the sedimentation rates over a time period of up to 100 years. Combined with the measurements of organic carbon concentration, carbon burial rates could be calculated at both farm and reference sites.

carbon accumulation rate; Pb-210 geochronology; Sediment core

Collins, William T; Boderskov, Teis; Sondak, Calvyn F A; Abdul, Al-Jeria; Boyce, Joshua; Reilly-Cayten, Megan; Neumeyer, Fritz; Cousteau, Alexandra; San Martin, Isidro; Marti, Elisa; Funderud, Jon; Borrero-Santiago, Ana R; Surugau, Noumie; Ranivoarivelo, Lanto; Pascal, Fred; Joanne, Paul; Chung, Ik Kyo; Choi, Chang Geun; Hori, Masakazu; Albasri, Hatim (in review): Carbon Burial in Sediments below Seaweed Farms. Nature Climate Change

Duarte, Carlos Manuel; Delgado-Huertas, Antonio; Marti, Elisa; Gasser, Beat; San Martin, Isidro; Cousteau, Alexandra; Neumeyer, Fritz; Reilly-Cayten, Megan; Boyce, Joshua; Kuwae, Tomohiro; Hori, Masakazu; Miyajima, Toshihiro; Price, Nichole N; Arnold, Suzanne N; Ricart, Aurora M; Davis, Simon; Surugau, Noumie; Abdul, Al-Jeria; Wu, Jiaping; Xiao, Xi; Chung, Ik Kyo; Choi, Chang Geun; Sondak, Calvyn F A; Albasri, Hatim; Krause-Jensen, Dorte; Bruhn, Annette; Boderskov, Teis; Hancke, Kasper; Funderud, Jon; Borrero-Santiago, Ana R; Pascal, Fred; Joanne, Paul; Ranivoarivelo, Lanto; Collins, William T; Clark, Jennifer; Gutierrez, Juan Fermin; Riquelme, Ricardo; Avila, Marcela; Macreadie, Peter I; Masque, P (in review): Carbon Burial in Sediments below Seaweed Farms. bioRxiv, https://doi.org/10.1101/2023.01.02.522332

Median Latitude: 21.717666 * Median Longitude: 52.766723 * South-bound Latitude: -41.908389 * West-bound Longitude: -125.086550 * North-bound Latitude: 63.716417 * East-bound Longitude: 139.921635

Date/Time Start: 2020-10-17T03:00:00 * Date/Time End: 2021-11-26T00:00:00

Minimum DEPTH, sediment/rock: 0.0025 m * Maximum DEPTH, sediment/rock: 1.3700 m

Ariake_Sea_Farm_AH * Latitude: 33.084370 * Longitude: 130.174200 * Date/Time: 2021-05-23T23:10:00 * Elevation: -5.0 m * Penetration: 130 cm * Recovery: 100 cm * Location: Japan * Campaign: OCEANS_2050_Japan (Ariake Sea/Seto Inland Sea/Tokyo Bay) * Method/Device: Hand corer (HCOR) * Comment: Manual coring by SCUBA divers, inner diameter of PVC tube: 67mm

Ariake_Sea_Farm_AR * Latitude: 33.135810 * Longitude: 130.221720 * Date/Time: 2021-05-23T23:55:00 * Elevation: -5.0 m * Penetration: 136 cm * Recovery: 96 cm * Location: Japan * Campaign: OCEANS_2050_Japan (Ariake Sea/Seto Inland Sea/Tokyo Bay) * Method/Device: Hand corer (HCOR) * Comment: Manual coring by SCUBA divers, inner diameter of PVC tube: 67mm

Ariake_Sea_Farm_AT * Latitude: 33.114550 * Longitude: 130.290350 * Date/Time: 2021-05-24T22:40:00 * Elevation: -5.0 m * Penetration: 140 cm * Recovery: 90 cm * Location: Japan * Campaign: OCEANS_2050_Japan (Ariake Sea/Seto Inland Sea/Tokyo Bay) * Method/Device: Hand corer (HCOR) * Comment: Manual coring by SCUBA divers, inner diameter of PVC tube: 67mm

# Name Short Name Unit Principal Investigator Method/Device Comment
1 Event label Event
2 LATITUDE Latitude Geocode
3 LONGITUDE Longitude Duarte, Carlos Manuel Geocode
4 Elevation of event Elevation m
5 DATE/TIME Date/Time Duarte, Carlos Manuel Geocode – Date/time of sampling
6 DATE/TIME Date/Time Duarte, Carlos Manuel Geocode – Date of sampling
7 Diameter Diameter cm Duarte, Carlos Manuel
8 Sample ID Sample ID Duarte, Carlos Manuel
9 Depth, top/min Depth top m Masqué, Pere
10 Depth, bottom/max Depth bot m Masqué, Pere
11 DEPTH, sediment/rock Depth sed m Masqué, Pere Geocode
12 Dry mass Dry m g Masqué, Pere
13 Dry mass per area Dry m area g/cm2 Masqué, Pere Calculated Accumulated mass bottom
14 Dry mass per area Dry m area g/cm2 Masqué, Pere Calculated Accumulated mass middle
15 Density, dry bulk DBD g/cm3 Masqué, Pere Calculated
16 Lead-210 210Pb Bq/kg Masqué, Pere Alpha spectroscopy Total
17 Lead-210, uncertainty 210Pb unc ± Masqué, Pere Calculated Propagated error
18 Radium-226 226Ra Bq/kg Masqué, Pere Gamma spectrometry
19 Radium-226, uncertainty 226Ra unc ± Masqué, Pere Calculated Propagated error
20 Lead-210 excess 210Pb xs Bq/kg Masqué, Pere Estimated
21 Carbon, organic C org % Granados, Arsenio Element analyser CNS, Carlo Erba NA1500