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Mudflats are places without vegetation where low tides leave soft muddy sediments exposed to the air. They are important feeding areas for many birds and fish.

Mudflats are teeming with worms, small crustaceans such as crabs and burrowing shrimp, and a variety of snails and other molluscs, many of which use broken down organic debris washed into these areas for food.

Mudflats are made up of very fine particles that restrict water movement into the soil and have little oxygen below the surface. This contributes to the black colour and smelly gases produced in these habitats. These characteristics are due to the activities of bacteria that can survive in the thick airless mud.

Most animals that live in the mud have burrows or special features that allow them to get oxygen from the water above. Animals found in mudflats include Soldier Crab (Mictyris platycheles), Flatworm (Platyhelminthes), Moon Snail (Polinices conicus), Sharptailed Sandpiper (Calidris acuminate) and Wavy Volute (Amoria undulate).

Key Threats

  • Poor water quality entering the sea from catchments
  • Fishing or removal of animals and plants
  • Marine pests such as the European Green Crab (Carcinus meanus) or green algae known as Broccoli Weed (Codium fragile ssp. tomentosoides)which compete for food or space
  • Boat and anchor damage in shallow areas
  • Oil and chemical pollution
  • Climate change effects including sea level rise, warming sea surface temperatures, and increasing ocean acidity.

Where to see mudflats

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