There are currently over 70 seals in the Walton backwaters, a small but healthy breeding population which has risen from only 5 in 1986.

The colony of both harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) are unusually of a russet colouration for much of the year due to the iron oxide-rich mud on to which they haul out.

The seals enjoy resting on the mudbanks, and prefer areas where rivers flow into the sea, like the backwaters, because these waters are permanently ice-free.