Many thanks to everyone for comments on the ringing of Sanderling. The bird was ringed by Jeroen Reneerkens Zackenberg either passing through Iceland in spring or on the Greenland breeding grounds (Stewart Holohan).
Birdwatch Ireland also gave feedback referencing an excellent video on You Tube:
This amazing footage was taken in Greenland this summer by a Dutch team (led by Jeroen Reneerkens) who have been monitoring breeding Sanderling in Greenland for the past 6 summers. Sanderling breed in the high Arctic and migrate long-distances, wintering further south, often seen feeding along sandier shores. Based on recent colour-ringing resightings, Jeroen's work has confirmed that some of the Greenland population overwinters in Ireland (where peak counts of around 3,000 birds have been recorded on I-WeBS counts) with others moving through as they head further south to Southern Europe and Africa.
Thanks again to David Hill for the pic: