Around the Zuiderzee, polders were diked, and within these polders, new parishes arose. In the early 20th century the diverted river was diked and channelized. The Cultus Bay Estuary has been diked off, minimising open tidal exchange. Dutch, Swedish and English settlers diked and drained parts of the marsh for grazing. In the early 1900s the wetlands at Roberts Landing were diked. Formerly it had been diked and ditched to create pasture for dairy cows. Burning petroleum spilled from the tank's vents into a diked area surrounding the tank. The area was diked by monks of the abbeys of Ten Duinen and Ter Doest. The Dove Elbe (literally in ) was diked off in 1437/38 at Gammer Ort. However, this has now been diked and converted to commercial agriculture. They diked the island and successfully operated agriculture. Gunther diked the island and ran dairy cattle there for nearly 40 years. Wilhelminadorp was founded in 1812, when the Wilhelminapolder was diked. The island of Pellworm was separated from neighbouring Nordstrand and only diked again in 1550. In 1754 the eastern part, the "Ooster Bildtpollen" was diked.