A complete transect of surface water samples from the North Sea to the Canary Islands was collected during a continuous period in 2010. The samples were analyzed for total I-129 and I-127 isotopes and their iodide and iodate species. The results indicate a large variability in the total I-129 and its species along the transect, whereas less change and variation are observed for the total I-127 and its species. Transport of I-129 fromthe western English Channel via Biscay Bay is the main source of I-129 in the northeastern Atlantic Ocean.