| Site of Special Scientific Interest | |
 View across the Tamar estuary south ofBere Ferrers, looking towardsCargreen | |
  Location within Cornwall Show map of Cornwall Tamar–Tavy Estuary (England) Show map of England | |
| Location | Cornwall, Devon |
|---|---|
| Grid reference | SX435591 |
| Coordinates | 50°24′41″N4°12′12″W / 50.4113°N 4.2032°W /50.4113; -4.2032 |
| Interest | Biological |
| Area | 1,422.3 hectares (14.2 km2; 5.49 sq mi) |
| Notification | 1991 (1991) |
| Natural England website | |
TheTamar–Tavy Estuary is aSite of Special Scientific Interest (SSSI)[1] covering the tidalestuaries of theRiver Tamar and theRiver Tavy on the border betweenCornwall andDevon in England, UK. Parts of the land designated as theTamar–Tavy Estuary SSSI are owned by theNational Trust and parts are owned by theMinistry of Defence[2] and theDiocese of Truro[3] also owns land in this SSSI. Part of the Tamar estuary also forms the Tamar Estuary Nature Reserve, owned by theCornwall Wildlife Trust. The site was designated in 1991 for its biodiversity and varying habitats that support manywader andwildfowl species, as well as the special interest of its marine biology.
The 1,422-hectare (3,510-acre) SSSI encompasses the entirety of the tidal regions of the Tamar; fromGunnislake down to theTamar Bridge in the south, where it forms theHamoaze, and the River Tavy fromLopwell to its discharge in the Tamar. The site also includes Kingsmill Lake, Tamerton Lake and a few other tributary streams of the Tamar, as well as the marshes aroundMorwellham Quay.[4]
The site forms part of theTamar Estuaries ComplexSpecial Protection Area (SPA), along with the estuary of theRiver Lynher andSt John's Lake,[5] as well as forming part of thePlymouth Sound and EstuariesSpecial Area of Conservation (SAC).[6]
The Cornwall Wildlife Trust owns the 109 hectares (270 acres) Tamar Estuarynature reserve around Kingsmill Lake, belowLandulph,[7][8] andLopwell Dam is aLocal Nature Reserve, covering the dam and surrounding woodlands.[9]
The SSSI, due to its habitats, is of international importance fornature conservation, in particular as awintering site for wildfowl and wader birds.[10]
Mudflats form the lower reaches of the estuary system and are bordered bysalt marsh,inundation grassland and rocky shoreline habitats. These mainly contain common saltmarsh-grass (Puccinellia maritima),red fescue andsea couch, as well as two nationally scarce species of grass: stiff saltmarsh-grass (Puccinellia rupestris) andbulbous foxtail. The upstream part of the system supportsfreshwater marsh,fen,rush pasture andreedmarsh habitats, along with wooded valleys in places. Species include thecommon reed and the only known population in theBritish Isles of triangular club-rush, part of the genusSchoenoplectus.[10]
The mudflats attract more than 20% of the British wintering population of the uncommonpied avocet. They additionally supportblack-tailed godwit,common redshank,dunlin,whimbrel,greenshank,spotted redshank andgreen sandpiper during the wintering period,[10] with the first birds arriving in October and leaving again throughout March.[8]
The highly variable salinity along the transition from marine estuary to river allows for a diverse marine culture. Seaweeds,green algae and communities ofpolychaete worms are all found in the estuary system; nearCalstock is found the shrimpPalaemon longirostris, which has been recorded in only two other estuaries in Britain.[10] The estuary is also one of only two sites in the UK where the fish,allis shad, spawn.[11]
Other larger animals found in undisturbed parts of the SSSI include theEuropean otter, thecommon kingfisher[10] anddormice.[9]
Media related toTamar Estuary at Wikimedia Commons
Media related toTavy Estuary at Wikimedia Commons
