Fenland Eels were formerly highly prized, being caught in large numbers in the many drainage ditches of the flatlands around Cambridge and Ely.
The Domesday Survey lists many of the towns and villages in the area in terms of how-many eels-per-year they could provide, the largest being Doddington and the lands of the Abbot of Ely yielding 27,150 eels. Eels were almost a currency in the area, the stone for the cathedrals at Ely and Peterborough being bought with them.