Data from: Brucite-inspired ocean alkalinity enhancement alters the biogeochemistry and composition of a phytoplankton community: A Santa Barbara channel case report
Authors/Creators
- 1. University of California, Santa Barbara
Description
The dramatic impacts of global climate change have driven marine carbon dioxide removal (mCDR) innovation, including ocean alkalinity enhancement (OAE), in an attempt to keep global warming under 2 °C. We experimented to assess the impacts of brucite-inspired alkalinity addition (BIAA) as an OAE approach on the carbonate chemistry, biogeochemistry, and composition of the Santa Barbara Channel phytoplankton community sourced from a spring upwelling event. The BIAA treatment used MgCl2 * 6H2O and NaOH to yield a total alkalinity (TA) concentration of 3000 µmol/kg, in contrast with the untreated seawater controls (TA = 2300 µmol/kg). Our results suggest that BIAA altered the phytoplankton community composition, including reduced contribution of diatoms and enhanced numbers of Prymnesiophyceae (coccolithophores and Phaeocystis sp.). These results are in agreement with observations that biogenic silica content was lower under BIAA treatment. While the concentration of particulate inorganic carbon was consistently higher compared to controls, these differences were not statistically significant. Results revealed no differences between control and BIAA treatment in particulate organic carbon and particulate organic nitrogen concentrations. The proxy for cellular photosynthetic health, Fv/Fm, revealed that cells were photosynthetically healthy for both control and BIAA treatments, but values were lower in the BIAA treatment at the beginning of the exponential phase. While statistical power limitations of laboratory results might restrict applicability to other systems, our overall results suggest that BIAA has a differential impact on phytoplankton functional groups and their biogeochemical performance.
Notes
Funding provided by: University of California, Santa Barbara
ROR ID: https://ror.org/02t274463
Award Number: CF-202204-02452
Funding provided by: University of California, Santa Barbara
ROR ID: https://ror.org/02t274463
Award Number: CF-202311-08493
Funding provided by: Carbon To The Sea
ROR ID:
Award Number:
Funding provided by: United States Department of Energy
ROR ID: https://ror.org/01bj3aw27
Award Number: A24-2263-S001
Methods
This dataset comprises data from analyzed seawater samples sourced from a 12-day, laboratory-based experiment during a seasonal upwelling event in spring 2023 and examines the impacts of magnesium-based alkalinity addition upon the carbonate chemistry, biogeochemistry, and phytoplankton community of the Santa Barbara Channel (SBC). Whole water was sourced from the SBC in a single-day sourcing event, and was filtered in-field to exclude zooplankton and then immediately transported back to the lab for additional filtration and preparation for a same-day experiment start. We utilized a "brucite-inspired" alkalinity addition (BIAA) approach, which consisted of adding MgCl2 * 6H2O and NaOH to yield a total alkalinity (TA) concentration of 3000 µmol/kg, in contrast with the untreated seawater controls (TA = 2300 µmol/kg). We used a full-factorial experimental design consisting of 4 treatments: abiotic no alkalinity added (Control-A), biotic no alkalinity added (Control-B), abiotic with BIAA (BIAA-A), biotic with BIAA (BIAA-B). Sampling occurred every third day of the experiment, with 3 independent replicate bottles being sacrificed from every treatment on every sampling day. Samples were analyzed for pH, Total Alkalinity, salinity, dissolved inorganic phosphate, dissolved inorganic silicate, and temperature to then calculate the remaining parameters of the seawater carbonate chemistry system using the program CO2Sys. Samples were also analyzed for the following biological and chemical indicators that have relevance to biogeochemistry and planktonic physiology: particulate organic carbon (POC); particulate organic nitrogen (PON); particulate inorganic carbon (PIC) a.k.a. CaCO3; dissolved Ca, Mg, and Na; dissolved inorganic nutrients (silicate, phosphate, nitrite+nitrate); biogenic silica (BSi); photosynthetic properties (Fv/Fm and FixArea). Samples were also processed via light microscopy to generate phytoplankton community composition and growth data (cell densities over time with genus-based cell identifications).
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Additional details
Related works
- Is source of
- 10.5061/dryad.9cnp5hqvk (DOI)