In 1949 Grace and Ian Telfer, an NHSN member, decided to mark seals in an attempt to follow their movements. Though grey seals are resident on the Farnes, nothing was known about them outside the breeding season. The first seals were tagged in 1951, and within fifteen days the first marked seal was recovered in Norway. This was ground breaking research as no one had realised how far the Grey Seals were traveling.