Salinity was measured with a benchtop salinometer (Orion StarTM A12, Thermo Scientific), which was calibrated using MilliQ water and known salinity CRM seawater before each sample analysis. Calcium ([Ca2+]) concentration was measured using automatic potentiometric titration with ethylene glycol tetraacetic acid (EGTA), with a precision of ±0.2% [59]. A Metrohm® Titrando calcium-selective electrode on a titration system (Metrohm Titrando 888) was used to detect the endpoint.
AGE model 2100 Minisal salinometer used by HOT
Guildline Portasal 8410 salinometer used by CARIACO
Guildline 8400 bench salinometer used by HOT, CVOO, K2, KNOT, Irminger & Iceland Sea TS.
OPTIMARE Precision salinometer OPS-20 used by CVOO
PorterSal salinomters used by OWSM