The Tamar–Tavy Estuary is a

Site of Special Scientific Interest A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle of ...

(SSSI) covering the tidal

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

of the

River Tamar The Tamar (; kw, Dowr Tamar) is a river in south west England, that forms most of the border between Devon (to the east) and Cornwall (to the west). A part of the Tamar Valley is a World Heritage Site due to its historic mining activities. T ...

and the

River Tavy The Tavy () is a river on Dartmoor, Devon, England. The name derives from the Brythonic root "Tam", once thought to mean 'dark' but now generally understood to mean 'to flow'. It has given its name to the town of Tavistock and the villages o ...

on the border between

Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...

and

Devon Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is ...

in England, UK. Part of the Tamar estuary also forms the Tamar Estuary Nature Reserve, owned by the

Cornwall Wildlife Trust The Cornwall Wildlife Trust is a charitable organisation founded in 1962 that is concerned solely with Cornwall, England. It deals with the conservation and preservation of Cornwall's wildlife, geology and habitats managing over 50 nature reser ...

. The site was designated in 1991 for its biodiversity and varying habitats that support many

wader 245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...

and

wildfowl The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, floating on ...

species, as well as the special interest of its marine biology.

Geography

The SSSI encompasses the entirety of the tidal regions of the Tamar; from

Gunnislake Gunnislake ( kw, Dowrgonna) is a large village in east Cornwall, England, United Kingdom. It is situated in the Tamar Valley approximately ten miles (16 km) north of Plymouth Gunnislake is in the civil parish of Calstock and is close to C ...

down to the

Tamar Bridge The Tamar Bridge is a suspension bridge over the River Tamar between Saltash, Cornwall and Plymouth, Devon in southwest England. It is long, running adjacent to the Royal Albert Bridge, and part of the A38, a main road between the two counti ...

in the south, where it forms the

Hamoaze The Hamoaze (; ) is an estuarine stretch of the tidal River Tamar, between its confluence with the River Lynher and Plymouth Sound, England. The name first appears as ''ryver of Hamose'' in 1588 and it originally most likely applied just to a ...

, and the River Tavy from

Lopwell Lopwell is a site of natural beauty situated at the normal tidal limit of the River Tavy, 3 miles from north Plymouth and 7 miles from Tavistock, Devon Tavistock ( ) is an ancient stannary and market town within West Devon, England. It is ...

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 around

Morwellham Quay Morwellham Quay is an historic river port in Devon, England that developed to support the local mines. The port had its peak in the Victorian era and is now run as a tourist attraction and museum. It is the terminus of the Tavistock Canal, and ...

. The site forms part of the ''Tamar Estuaries Complex''

Special Protection Area A Special Protection Area (SPA) is a designation under the European Union Directive on the Conservation of Wild Birds. Under the Directive, Member States of the European Union (EU) have a duty to safeguard the habitats of migratory birds and cert ...

(SPA), along with the estuary of the

River Lynher The River Lynher ( kw, Linar) (or St Germans River downstream from its confluence with the Tiddy) flows through east Cornwall, England, and enters the River Tamar at the Hamoaze, which in turn flows into Plymouth Sound. Navigation The normal ...

and St John's Lake, as well as forming part of the ''

Plymouth Sound Plymouth Sound, or locally just The Sound, is a deep inlet or sound in the English Channel near Plymouth in England. Description Its southwest and southeast corners are Penlee Point in Cornwall and Wembury Point in Devon, a distance of abo ...

and Estuaries''

Special Area of Conservation A Special Area of Conservation (SAC) is defined in the European Union's Habitats Directive (92/43/EEC), also known as the ''Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora''. They are to protect the 220 habitats and ap ...

(SAC). The Cornwall Wildlife Trust owns the Tamar Estuary

nature reserve A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, or features of geological or ...

around Kingsmill Lake, below

Landulph Landulph ( kw, Lanndhylyk) is a hamlet and a rural civil parish in south-east Cornwall, England, United Kingdom. It is about 3 miles (5 km) north of Saltash in the St Germans Registration District. The parish lies on the River Tamar (which ...

,Ordnance Survey: Explorer map sheet 108 ''Lower Tamar Valley & Plymouth'' and

Lopwell Dam Lopwell is a site of natural beauty situated at the normal tidal limit of the River Tavy, 3 miles from north Plymouth and 7 miles from Tavistock, Devon, England. Lopwell Dam is a Local Nature Reserve consisting of several different habitats incl ...

is a Local Nature Reserve, covering the dam and surrounding woodlands.

Wildlife and ecology

The SSSI, due to its habitats, is of international importance for

nature conservation Nature conservation is the moral philosophy and conservation movement focused on protecting species from extinction, maintaining and restoring habitats, enhancing ecosystem services, and protecting biological diversity. A range of values unde ...

, in particular as a wintering site for wildfowl and wader birds.

Mudflat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal fl ...

s form the lower reaches of the estuary system and are bordered by

salt marsh A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominated ...

, inundation grassland and rocky shoreline habitats. These mainly contain common saltmarsh-grass (''

Puccinellia maritima ''Puccinellia maritima'' is a species of grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of na ...

''),

red fescue ''Festuca rubra'' is a species of grass known by the common name red fescue or creeping red fescue. It is widespread across much of the Northern Hemisphere and can tolerate many habitats and climates. It is best adapted to well-drained soils in c ...

and

sea couch ''Elymus pungens'', the sea couch grass, is a species of grass of the genus ''Elymus (plant), Elymus'' in the family Poaceae. It is a common grass species native to Europe and Asia. ''Elymus pungens'' is typically found in sandy, and saline envir ...

, as well as two nationally scarce species of grass: stiff saltmarsh-grass (''

Puccinellia rupestris ''Puccinellia'' is a genus of plants in the Poaceae, grass family, known as alkali grass or salt grass. These grasses grow in wet environments, often in Saline water, saline or alkaline conditions. They are native to temperate to Arctic regions ...

'') and

bulbous foxtail In botany, a bulb is structurally a short Plant stem, stem with fleshy leaf, leaves or leaf basesBell, A.D. 1997. ''Plant form: an illustrated guide to flowering plant morphology''. Oxford University Press, Oxford, U.K. that function as food st ...

. The upstream part of the system supports

freshwater marsh A freshwater marsh is a non-tidal, non-forested marsh wetland that contains fresh water, and is continuously or frequently flooded. Freshwater marshes primarily consist of sedges, grasses, and emergent plants. Freshwater marshes are usually found ...

fen A fen is a type of peat-accumulating wetland fed by mineral-rich ground or surface water. It is one of the main types of wetlands along with marshes, swamps, and bogs. Bogs and fens, both peat-forming ecosystems, are also known as mires. T ...

, rush pasture and reedmarsh habitats, along with wooded valleys in places. Species include the

common reed ''Phragmites australis'', known as the common reed, is a species of plant. It is a broadly distributed wetland grass that can grow up to tall. Description ''Phragmites australis'' commonly forms extensive stands (known as reed beds), which may ...

and the only known population in the

British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...

of triangular club-rush, part of the genus ''

Schoenoplectus ''Schoenoplectus'' (club-rush ld World species bulrush or tule ew World species is a genus of plants in the sedges with a cosmopolitan distribution. Note that the name bulrush is also applied to species in the unrelated genus ''Typha'' as well ...

''. The mudflats attract more than 20% of the British wintering population of the uncommon

pied avocet The pied avocet (''Recurvirostra avosetta'') is a large black and white wader in the avocet and stilt family, Recurvirostridae. They breed in temperate Europe and across the Palearctic to Central Asia then on to the Russian Far East. It is a mig ...

. They additionally support

black-tailed godwit The black-tailed godwit (''Limosa limosa'') is a large, long-legged, long-billed shorebird first described by Carl Linnaeus in 1758. It is a member of the godwit genus, ''Limosa''. There are four subspecies, all with orange head, neck and chest ...

common redshank The common redshank or simply redshank (''Tringa totanus'') is a Eurasian wader in the large family Scolopacidae. Taxonomy The common redshank was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his ...

dunlin The dunlin (''Calidris alpina'') is a small wader, formerly sometimes separated with the other "stints" in the genus ''Erolia''. The English name is a dialect form of "dunling", first recorded in 1531–1532. It derives from ''dun'', "dull brown ...

, whimbrel,

greenshank The common greenshank (''Tringa nebularia'') is a wader in the large family Scolopacidae, the typical waders. The genus name ''Tringa'' is the New Latin name given to the green sandpiper by Aldrovandus in 1599 based on Ancient Greek ''trungas'' ...

spotted redshank The spotted redshank (''Tringa erythropus'') is a wader (shorebird) in the large bird family Scolopacidae. The genus name ''Tringa'' is the New Latin name given to the green sandpiper by Aldrovandus in 1599 based on Ancient Greek ''trungas'', a ...

and

green sandpiper The green sandpiper (''Tringa ochropus'') is a small wader (shorebird) of the Old World. The green sandpiper represents an ancient lineage of the genus ''Tringa''; its only close living relative is the solitary sandpiper (''T. solitaria''). They ...

during the wintering period, with the first birds arriving in October and leaving again throughout March. The highly variable salinity along the transition from marine estuary to river allows for a diverse marine culture. Seaweeds,

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

and communities of

polychaete worm Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are mad ...

s are all found in the estuary system; near

Calstock Calstock ( kw, Kalstok) is a civil parish and a large village in south east Cornwall, England, United Kingdom, on the border with Devon. The village is situated on the River Tamar south west of Tavistock and north of Plymouth. The parish had ...

is found the shrimp ''

Palaemon longirostris ''Palaemon longirostris'' is a species of shrimp of the family Palaemonidae. It is considered an invasive species in the Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east ...

'', which has been recorded in only two other estuaries in Britain. The estuary is also one of only two sites in the UK where the fish,

allis shad The allis shad (''Alosa alosa'') is a widespread Northeast Atlantic species of fish in the Clupeidae, herring family, Clupeidae. It is an Fish migration, anadromous fish which migrates into fresh water to spawn. It is found in the eastern Atlan ...

, spawn. Other larger animals found in undisturbed parts of the SSSI include the

European otter The Eurasian otter (''Lutra lutra''), also known as the European otter, Eurasian river otter, common otter, and Old World otter, is a semiaquatic mammal native to Eurasia. The most widely distributed member of the otter subfamily (Lutrinae) of th ...

, the

common kingfisher The common kingfisher (''Alcedo atthis''), also known as the Eurasian kingfisher and river kingfisher, is a small kingfisher with seven subspecies recognized within its wide distribution across Eurasia and North Africa. It is resident in much of ...

and

dormice A dormouse is a rodent of the family Gliridae (this family is also variously called Myoxidae or Muscardinidae by different taxonomists). Dormice are nocturnal animals found in Africa, Asia, and Europe. They are named for their long, dormant hibe ...

Gallery

Image:River Tamar from Calstock Viaduct - geograph.org.uk - 73430.jpg, River Tamar from

Calstock Viaduct Calstock railway station is an unstaffed railway station on the Tamar Valley Line serving the village of Calstock in Cornwall, United Kingdom. It is situated at the north end of Calstock Viaduct which carries the railway at high level over t ...

File:River Tamar - geograph.org.uk - 326342.jpg, Mudflats and salt marshes on the lower reaches of the estuary system File:Salt marsh on the bank of the River Tamar - geograph.org.uk - 469684.jpg, Salt marsh on a lower bank of the River Tamar File:River Tamar from Cotehele Quay - geograph.org.uk - 196017.jpg, A reedmarsh on the upper reaches of the Tamar, at

Cotehele Cotehele ( kw, Kosheyl) is a medieval house with Tudor additions, situated in the parish of Calstock in the east of Cornwall, England, and now belonging to the National Trust. It is a rambling granite and slate-stone manor house on the banks ...

File:Lopwell Dam - geograph.org.uk - 84226.jpg, The Lopwell Dam, a

weir A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of l ...

that is the tidal limit of the River Tavy

References

External links

{{DEFAULTSORT:Tamar-Tavy Estuary Sites of Special Scientific Interest in Cornwall Sites of Special Scientific Interest in Devon Sites of Special Scientific Interest notified in 1991 Special Protection Areas in England Nature reserves of the Cornwall Wildlife Trust Estuaries of England River Tamar Cornish coast