=== METHOD === 
Sediment-water fluxes were measured in situ using benthic chamber landers (Kononets et al. 2021). O2 was measured by optodes (Aanderaa Data Instruments, Norway). DIC was measured using an automated system based on infrared detection of CO2 (Li-Cor 6262; Nilsson et al., 2019). Nutrient samples were filtered and measured by segmented flow analysis (QuAAtro, XY-3 Sampler, Seal Analytical 2015). Concentrations of CH4 were determined by headspace analysis on a gas chromatograph (GC 8A, Shimadzu) equipped with a PorapakTM N column (80-100 mesh) and a flame ionization detector (FID), and using dinitrogen (N2) as carrier gas. The CH4 concentrations in the water were calculated based on the distribution coefficient dependent on temperature and salinity (Yamamoto et al., 1976). Fluxes were calculated by fitting a simple or quadratic linear least square regression model to data of concentrations in the water samples versus time, followed by multiplication of the slope of the regression line with the chamber height.

Kononets, M.Y., Tengberg, A., Nilsson, M.M., Ekeroth, N., Hylén, A., van de Velde, S.J., Rütting, T., Bonaglia, S., Blomqvist, S., Hall, P.O.J., 2021. In situ incubations with Gothenburg benthic chamber landers: Applications and quality control. J. Mar. Syst. 214, 1–20. https://doi.org/doi.org/10.1016/j.jmarsys.2020.103475

Nilsson, M.M., Kononets, M.Y., Ekeroth, N., Viktorsson, L., Hylén, A., Sommer, S., Pfannkuche, O., Almroth-Rosell, E., Atamanchuk, D., Andersson, H.J., Roos, P., Tengberg, A., Hall, P.O.J., 2019. Organic carbon recycling in Baltic Sea sediments – An integrated estimate on the system scale based on in situ measurements. Mar. Chem. 209, 81–93. https://doi.org/doi.org/10.1016/j.marchem.2018.11.004

Yamamoto, S., Alcauskas, J.B., Croizer, T.E., 1976. Solubility of methane in distilled water and seawater. J. Chem. Eng. Data 21, 78–80.



 === FIELD EXPLANATION ===
Sampling - sampling occasion (June 2017, July 2018, October 2018, February 2019)

Site - sampling site (Ref, Farm)

Deployment - replicate chamber deployments (1, 2, 3)

Var - chemical compound 

Chamber - replicate incubation chambers 

Flux - sediment-water flux (mmol/m2/d)

Comment - identification of outlier points