The UK has more diverse landscapes than any area on Earth of comparable size
Resembling abstract art, the River Dee loops in great meanders through mudflats on either side. A closer look reveals the many small pools of water that sparkle in the sunlight, linked together by a network of tiny creeks draining the mudflats. From above it appears barren, and yet is one of our most productive landscapes.
On the mudflats, just beneath the surface coating of green algae, live shellfish, such as cockles and clams, along with mud snails and worms. They get their oxygen through breathing tubes that poke through the surface and filter the water for plankton. It is also a favourite environment for crustaceans such as shrimps. Birds, fish and crabs are regular visitors too, feeding on the tidal flats.
The mud is flooded by the tides twice a day, receiving nutrients from the sea water and the nearby saltmarshes, making it a rich and biodiverse environment.
Rivers naturally flow in bends, called meanders. Once a channel starts to follow a curved path, perhaps because of an obstacle like a rock or tree branch in its way, flows within the water serve to intensify this. Water flows slightly slower on the inside of a river bend because it has less far to travel, and this encourages it to dump more of its sediment.
On the outer bend the water flow is faster and this is where more erosion occurs. Over time the effect reinforces itself, so the meander becomes more curved until eventually it gets cut off and the river becomes a straight line.