The Helford River

This river, or estuary, where luxuriant green woods and fields meet the sea, has long been recognised for its scenic beauty and biological importance.

The shoreline is over 47km in length and includes a wide range of habitats, from the exposed rocky coasts at the mouth to the steep-sided muddy inland creeks. Residents and visitors alike, appreciate the peaceful atmosphere, many taking to the water in boats, whilst commercial activities are closely linked to the sea or tourist industry.

Map of the Helford River in Cornwall

Whilst statutory powers now exist for the conservation of key marine species and habitats, emphasis is still on the voluntary approach which is considered to be as important to achieve success in maintaining the area's outstanding environmental quality through the co-operation of the estuary users. It is the intention to encompass the interests of all land-owners, users and visitors that underpins the VMCA's approach, together with rigorous standards of data-collection and presentation.

Helford River

Statutory designations:

The Helford Estuary falls into the recently identified Fal and Helford Special Area of Conservation (SAC) which is complex, ranging from exposed to sheltered marine habitats and qualifying in respect of the following habitats:-

• Large shallow inlets and bays
• Atlantic salt meadows (Fal rather than Helford)
• Mudflats and sandflats not covered by seawater at low tide
• Sandbanks which are slightly covered by seawater at all times (The eelgrass beds and maerl are sub features)

The SAC also supports Biodiversity Action Plans (BAPs) for species and habitats. The Helford is one of the few locations where the Fan mussel (Atrina fragilis) survives in Britain, the whole estuary is a statutory Bass (Dicentrarchus labrax) Nursery Area and the native oyster fishery is important. It is the type locality of the rarely recorded Couch's goby (Gobius couchi) and there is a wide diversity of marine communities associated with eelgrass, a rich algal flora and many south-westerly species.

Merthen Wood has been designated as a Site of Special Scientific Interest (SSSI). The shore at the mouth of The Helford from Rosemullion Head southward was one of the first intertidal SSSIs, followed more recently by much of the intertidal area within the estuary complex. The whole Helford River system falls locally into a Cornwall Area of Outstanding Natural Beauty and is identified by the Cornwall Wildlife Trust as a Cornwall Nature Conservation Site within Kerrier District.

Physical features

The Helford Estuary, situated on the east side of the Lizard Peninsula in south west Cornwall, is an ancient river valley or ria which was drowned when the sea level rose at the end of the last ice age approximately 10,000 years ago. The main estuary, which is some 9.2km long, has numerous creeks running off it, many of which dry to mud at low tide. The tidal area is 568ha, intertidal area 186ha, and the shoreline is 44.3km at extreme high water spring level (Davidson et al, 1991). It is well sheltered from all westerly winds, but is open to winds from the east. The nearby harbour at Falmouth is larger, more sheltered and easier of access by land and sea and therefore attracts larger numbers of visitors. The climate is equable with some particularly mild winters recently.

Help preserve the Helfod River eelgrass beds -
aerial photography supplied by
Technical Services, Cornwall County Council

There is very little freshwater input relative to the total volume of water within the river and, generally, mixing would appear to be good. The salinity varies little within the tidal waters except in the upper reaches and creeks after very heavy rain. The estuary may be described as a many-fingered arm of the sea.

The oldest rocks of the Helford Estuary are the Middle Devonian outcrops on both banks of the lower estuary composed of greywackes, slates and conglomerates. Sedimentation continued until the end of the Carboniferous Period when a large mass of granite intruded under the south west peninsula, the southern limit of which is beneath Constantine above the north shore.

Historically there have been no extensive mining complexes in the immediate vicinity of the Helford Estuary area but the presence of numerous adits indicates a number of small ventures for copper, silver and tin. It is probable that tin streaming took place in the locality and in the 19th Century together with the expansion of larger mines contributed to a silting of the upper reaches of the waterway. Sediments would wash down the creeks and be redistributed along the main channel affecting the navigability of the upper estuary. These sediments could well have an appreciable tin content but are not likely to be worked as disturbance would be environmentally and aesthetically damaging.

Human use

The character of the Helford River has been shaped by the countless activities of people. Hunter-gatherer groups would have taken advantage of the sheltered shores and in due course woodland was cleared to create settlements, farms and early field systems. The waterway was an important trade route and small villages and quays grew up at the access points. Mills, fish cellars and transport links were developed at the heads of most creeks. Large coal, stone and timber- carrying barges frequented the port of Gweek as it rose to prominence following the build-up of Loe Bar which effectively cut off any possible sea access to Helston.

Now in the 21st century a commercial drilling rig company and boat repair yard carry on the maritime tradition and recreational craft throng the waterway whilst houses and hotels are scattered along its edges. Tourism has become one of the mainstays of the local economy.

Biological features

The sheltered and varied habitats that the river provides support rich populations of shore life. These characteristics make it a particularly important nursery area for many species - including some fishes, molluscs and crustaceans - that move to shallow water for breeding. Observations are being undertaken and more work needs to be carried out on the shore ecosystems. Until the mid-1980s Bar Beach, Treath and Gillan areas used to support large beds of intertidal eelgrass which then dissapeared but is now (2006) showing signs of recovery. The subtidal beds are also flourishing and expanding. Fauna such as delicate fan worms which had declined have recovered and are wide spread.

At the mouth of the river, at Prisk Cove, are the rich and colourful rock pools which are to be found within the Rosemullion Site of Special Scientific Interest. Amongst the notable seaweeds present are species of Cystoseira, one of which is conspicuous by its iridescence. Rock pools occur within the river up as far as Helford Passage and Treath, but these are generally smaller and less diverse in their flora and fauna. Besides Prisk Cove other good examples of rocky shore are Men-aver reef just inside Nare Point and the Voose reef, the latter being the more sheltered. These areas are rich in marine life, and show a greater diversity than the more exposed boulder areas of Parsons Beach and Nare Point itself. For example, the undersides of the stones which are only rarely moved by wave action, are home to such creatures as porcelain crabs, anemones, starfish and chitons and provide shelter for fish which would be vulnerable to crushing amongst more mobile substrates.

Cuttlefish © A. Sutton

The rocky shores of Bosahan and Durgan have many overhangs and, being fully saline and sheltered, these areas are home to many species, such as sea-squirts and sponges. Twenty species of sea anemone have been found in the Helford Estuary since 1985. Among these are two nationally scarce species, the Trumpet Anemome (Aiptasia mutabilis) and the Ginger Tiny (Isozoanthus sulcatus).

Above the narrows at Helford Passage, the river is more sheltered and some sedimentation occurs. The shores of Treath, south side and Bar Beach, Helford Passage, north side, are a mixture of sand and mud and have a rich infauna. Of particular interest are the worm populations, the delicate tubeworms Myxicola infundibulum and Chaetopterus variopedatus , as well as the Peacock Worm (Sabella pavonina), which when the water is shallow, can be seen by the casual observer spreading its fan-like tentacles to catch food from the swirling water.

Upriver the tree-fringed tidal creeks, where Grey herons and Little egrets mingle, dry to mud supporting many invertebrates providing a useful source of food for many bird species whereas the open waters offer shelter to sea ducks, divers and grebes during the winter. Recent fish surveys have shown the beds of Common Cord-grass, or spartina (Spartina anglica), to be the favourite haunt of juvenile bass. No less than 80 species of fish have been recorded within the confines of the HVMCA: some of these are nationally rare or scarce and others are of economic importance.

The way forward

The Helford Marine Conservation Group aims to inform, educate and assist all sections of the user community. As many links as possible are maintained with statutory bodies and river users to ensure the highest achievable level of understanding and resourcing directed towards marine conservation. This whole biologically rich area deserves attention and protection but this will only happen if the people using the Helford River and its shores want it to happen - community, commerce and conservation working together.

Other items that may be of interest:

• The Helford River - An Area of Outstanding Natural Beauty