“…Relative to open ocean and outer shelf waters, the concentration of dissolved iodine in coastal inner shelf waters is lower (Truesdale, 1978;Truesdale, 1994;Truesdale and Upstill-Goddard, 2003;Satoh et al, 2019a;Satoh et al, 2023;Shi et al, 2023). The reason for this is not well known (Chance et al, 2014), though a chemical transformation to a particulate fraction may account for the apparent depreciated soluble iodine concentrations (Truesdale, 1994;Truesdale and Upstill-Goddard, 2003;Satoh et al, 2019a;Satoh et al, 2023). Processes directly influencing the iodine cycle in wider coastal environments include interaction with dissolved organic material during its remineralization and sorption to particulate material (Truesdale, 1978;Tian et al, 1996;Satoh et al, 2019a;Shi et al, 2023), the mixing of deeper low oxygen high iodide waters to the surface (Shi et al, 2023), and significant changes in dissolved organic iodine (DOI) concentration (DDOI up to 100 nM; Satoh et al, 2019a).…”