We report weekly observations of volatile organic iodocarbons (CH 3 I, CH 2 ClI and CH 2 I 2 ) over the time-period May 2015 to December 2017 from 4 depths in Bedford Basin, a coastal fjord (70 m deep) on the Atlantic coast of Canada. The fjord is subject to winter-time mixing, seasonal stratification and bloom dynamics, subsurface oxygen depletion, local input of freshwater and occasional intrusions of higher density water from the adjacent continental shelf. Near-surface concentrations showed strong seasonal and sub-seasonal variability which is compared with other coastal time-series. Relationships with other properties lead to the hypothesis that near-surface iodocarbon production is linked to reduction of iodate to iodide under conditions of post-bloom phytoplankton senescence, nutrient stress or viral lysis following seasonal disappearance of nutrients. The vertical variation of CH 2 I 2 and CH 2 ClI within the upper 10m is consistent with rapid photolysis of CH 2 I 2 . Average annual sea-to-air fluxes (62 nmol m −2 day −1 ) of total volatile organic iodine were slightly higher than observed in other coastal and shelf time-series and polyiodinated compounds contributed 85 % of the total flux. Fluxes were subject to strong interannual variability (2–3X) as a result, mainly, of wind-speed variability. Near-surface net production of CH 3 I averaged 1.0 pmol L −1 day −1 and was similar to rates in the English Channel but an order of magnitude higher than in shallow waters of the Kiel Fjord, Germany, possibly due to higher microbial degradation in the latter. The near-bottom (60 m) time-series showed evidence for CH 3 I production associated with organic matter degradation, and a possible switch from production of CH 3 I via an alkylation pathway to production of CH 2 I 2 by a haloform-type reaction. Near-bottom CH 3 I production varied strongly between years but was generally ca. 20 times lower than near-surface production. Post-intrusion decreases of iodocarbons at 60 m suggested removal timescales of 14, 65 and 70 days for CH 3 I, CH 2 I 2 and CH 2 ClI respectively.