Morecombe Bay is an unpredictable environment of marine and freshwater sediment deposition and erosion. The river Kent as it reaches the bay is carrying large amounts of sediment, due to its flow rate and relative short length. Deposition can be dynamic as the rivers course changes as it enters the bay.
Salt marsh is beginning to emerge on the Southern shore adjacent to Silverdale, as eroded material builds up and allows plants to gain a foothold in the sediment. It is thought that this process reflects a change that takes place approximately every 90 years, with the salt marsh on the opposite bank adjacent to Grange over Sands, retreating as the Kent moves closer to this bank.