Intertidal Mudflats

Mudflats are sedimentary intertidal habitats created by deposition in low energy coastal environments particularly estuaries and other sheltered areas.

Intertidal Mudflats

Photo: Paul Glendell/Natural England

Why are they important?

  • Mudflats are part of a habitat sequence between open water and saltmarsh, and have an important role in reducing the impact of waves upon saltmarshes, damage to coastal defences and flooding of low-lying land.
  • A wide range of invertebrates is supported including molluscs, annelids and lugworms.
  • Mudflats are highly productive, making them important feeding areas for birds. They support internationally important populations of migrant and wintering waders.
  • Due to their sheltered nature mudflats are important areas for fish, in particular flatfish, which use them as nursery areas.

Intertidal Mudflats in Sussex

Sussex has just over 1100 hectares of intertidal mudflats. Much of this occurs in a mosaic with saltmarsh and seagrass beds.

What are the threats?

  • Sea level rise is expected to result in the loss of up to 10000 hectares of intertidal mudflat by 2013, with much of this in southern England.
  • Land claim for development, and industry including hard flood defences.
  • Pollution from agricultural, industrial and urban sources.
  • Human disturbance from fishing and bait digging can have adverse impacts.
  • Introduction of invasive species such as Cord Grass.

Some associated species

  • Golden Plover Pluvialis apricaria
  • Atlantic Salmon Salmo salar
  • Lugworm Arenicola marina
  • Mud Shrimp Corophium volutator
  • Glasswort Salicornia europaea
  • Spiral Wrack Fucus spiralis


Photo: Steve Waterhouse

Advice on intertidal mudflats


Sussex Targets

Biodiversity Action Reporting System Website

Download the Intertidal Mudflats Habitat Action Plan