Action #6: Biological interplay with the carbonate system

Objectives: Eutrophication, and with it changes in primary production and mineralization, are of major concern for the Baltic Sea and the GoF PSS area in particular. The inorganic carbon cycle can be used as a powerful quantitative indicator in this complex interplay, as it is the major constituent of organic biomass, and the oxidation of organic carbon is by far the largest contributor to the oxygen demand in deeper waters. It becomes more and more evident that not only the summer N-fixation period but also the later part of the spring bloom show high variability in C/N/P ratios, thus the link of production of biomass to oxygen demand requires tracing of the carbon cycle. Homogenization of data flows and data quality, the definition of gaps, and integrated assessment and interpretation are essential to make full use of these data for ecosystem assessment in the GoF PSS target area.

Action Lead and other Partners (with contact persons): IOW (Rehder , Bittig), SYKE (Seppälä), FMI (Laakso, Honkanen), TALTECH (Lips, Kikas)

JS3 Platforms included: FerryBox: Silja Serenade and Finnmaid (SYKE, FMI, IOW), Silja Europa (TALTECH), Utö Observatory (FMI, SYKE), Keri Observatory (TALTECH), monitoring by R/V (All)

Other data sources and external partners for implementation: potential inclusion of data submitted to the SOCAT database on CO2 parameters in the area (e.g. SOOP Tavastland, Shark database entries of SMHI, data from other projects in the area).

Overall timetable of action: Some data are collected continuously over the course of JERICO-S3 as part of long-term measurement programs of the partners. A major focus will however lie in data collected over the years 2021-2022.

Description of action: We will assess the availability of carbon system data provided in the area and identify gaps and needs for quality control in the area. Surface pCO2 measurements are continuously operational on SOOP Finnmaid using ICOS-conform methodology, as well as on Silja Serenade and Silja Europa (assuming the current stop of operation due to the COCID 19 pandemic will end in spring 2021). The Action will promote the transfer of knowledge on data QA/QC, and improve homogenization and inter-comparability of data and protocols. The group will assess how the carbon system, biological and physical data may be jointly analysed and provide an outlook if there is a need to improve coordination of observations and if some key parameters need to be further included. 

Best practices used or developed: pCO2 measurements are in general following SOCAT recommendations; CT, AT measurements, are well established, yet currently calibrated by the entire community against an open ocean standard (CRM, Scripps). Currently, round-robin tests are on the way to check whether this is fully appropriate for brackish water samples. For pH, spectrophotometric measurements are now more and more established and will be further monitored and introduced for the monitoring of brackish waters. Streamlining and QC here will strongly follow and interact with WP 6, Task 6.3.3.

Data flows: pCO2 and continuous surface carbon parameters via SOCAT, discrete measurements from RV-based monitoring through established databases.

Data QC routines: SOCAT / ICOS routines and QC-ing as documented in the Guide for Best Practises for Ocean CO2 measurements (Dickson et al., 2007) will be followed and/or established for all data streams.

Data management issues: Data management issues are jointly analysed with WP6 T 6.3.3 with expected synergistic effects.

Expected results: The action will improve partners capacity to provide consistent high-quality carbonate system measurements and to analyse the results with auxiliary biological and physical data. The Action improves the overall coordination of carbonate system measurements in the region and contributes to pan-European integration.

Users of results: Scientists working with climate change and ecosystem functioning; managers making assessments of the effects of climate change, eutrophication, and acidification; other parties involved in carbonate measurements.

Dissemination of results: Results will be disseminated during scientific and management-supporting meetings and workshops, including those of JERICO-S3, ICOS ERIC, BOOS and HELCOM.  

Links: The action links to WP6 Task 6.3.3. working with the guidelines and strategy for carbonate systems data management. It also links to carbonate system actions in other PSS; the already existing link to the ICOS ERIC will be intensified.