The estuary’s unique environment is one of constant change, neither river nor sea water but a changing mixture of the two, with levels of salinity (dissolved salt concentration) occurring in zones ranging approximately from 5 to 30%. The mixing of fresh and sea waters and tidal movement create changing levels of salinity and nutrients, providing a fertile environment that can support large populations of animals, particularly invertebrates, fish and birds.
Ditches represent a key landscape and conservation feature of the grazing marshes. The ditch network is calculated to be over 2000 kilometres in length and is used to control water levels within the marshes and to provide wet fences for the management of livestock. With sympathetic management, ditches can provided important habitat for some species.
Grazing marsh is an area of periodically flooded pasture or meadow with ditches containing brackish or fresh water. The majority of grazing marshes around the estuary are semi-natural in origin; the result of containment, drainage and grazing. Grazing marsh provides important high tide roosts for waders and wildfowl and in spring, habitat for significant proportions of the estuary’s breeding birds.
Mudflats are intertidal habitat comprising soft sediment exposed at low tide. They are not vegetated, except for the presence of eelgrass (Britain’s only flowering marine plant) which occurs in sheltered sections of the estuary. Mudflats are highly productive ecosystems enabling them to support large numbers of invertebrates, waders and wildfowl. A square metre of mud contains the energy equivalent of sixteen chocolate bars. The mudflats of the estuary are the most extensive in Kent.
Reedbeds are important for a number of wetland plants and animals, which have been in decline for a number of years, leading them to be designated a UK BAP habitat. They are dominated by the Common reed (Phragmites autralis), which can grow to over four metres in height.
Saltmarshes are formed on mudflats that are high enough to be colonised by specialist plants capable of being frequently submerged in salt water. The plant roots and stems help bind the mud and surface vegetation, which slows down the flow of water, encouraging more silt to be deposited. This process enables the saltmarsh to maintain its height.
Built for flood defence, these form large expanses of grassland around the estuary. Many plants of interest occur along the estuary’s sea walls. The seaward wall of the embankment often supports plants typical of the upper zone of saltmarsh (less common naturally due to the presence of the sea walls) which can tolerate frequent inundation. Where clay has been extracted for sea wall construction, ‘borrow-dykes’ have been created, providing important reedbed habitat.
A shallow flow of water in a channel. Refers also to a Fleet. Locations include:Blackstump Creek, Halstow Creek, Milton Creek, Shepherds Creek, Capel Fleet, Elmley Fleet and Sharfleet Creek.
Refers to a headland of promontory. Locations include: Darnet Ness, Finsborough Ness, Hoo Ness, Sharp Ness and Shellness.
From the Old English word wase, meaning mud. Locations include: Bishop Ooze, Ham Ooze, Stoke Ooze and South Oaze
A extended stretch of land. Locations include: Clay Reach, Ferry Reach, Horse Reach and Long Reach
An area of low lying ground, regularly inundated with salt water. Locations include: Bishop Saltings, Hamgreen Saltings, Stoke Saltings and Twinney Saltings
A depositional landform, created by the longshore movement of sediment (such as sand or shingle). Locations include: Bartlett Spit, Folly Spit, Queenborough Spit and The Spit.