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Background to the project

The critically-endangered, Red List European eel (Anquilla anquilla) is a fascinating species with strong connections to the north Norfolk coast.

This project focussed on the eel in the River Glaven, north Norfolk - its ecology and its local cultural significance.  The project helped to re-connect current generations with the eel and its folklore - before those connections were lost forever. It also improved eel habitat in the river catchment, to encourage an increase in eel numbers, and improved scientific knowledge about eels.

Cultural significance

Enigmatic, charismatic and mysterious, the eel has long been exploited by humans. Eels were being caught and eaten 5,000 years before the birth of Christ - Aristotle and Pliny wrote about them; Romans regarded them as a peerless delicacy and Egyptians accorded them semi-sacred status. Many East Anglian fortunes were once built upon the eel harvest. Just within living memory of our oldest inhabitants, many villages would have had their own eel catcher and, during the annual eel runs, cart loads of eels would have been caught and sent to London to supply the numerous eel pie shops.

Now European eel populations have declined by over 90%, resulting in it being listed as an Annex II species protected under the 1992 European Commission Habitats Directive (92/43/EEC).

The cultural awareness of eels has declined at a similar rate. Whereas everyone living on the River Glaven would once have been familiar with eels, now it is a lucky few who have any interactions with this strange and magical fish.


The eel is a long, thin, muscular and rope-like fish of the order Anguilliformes. They are capable of growing to 1.5 m in length, though most are much smaller at up to 80 cm long. There is a continuous fin running along the top of the body to the tip of the tail and they are covered in slippery mucus which allows them to survive out of water for extended periods, meaning that they can move across the ground between water sources and colonise isolated ponds and ditches.

During their time in our rivers, eels are essentially scavengers, feeding voraciously in the summer on worms, small fish, dead fish, molluscs, and other bottom-living animals. In the winter they become less active, often lying dormant and half-buried in the muddy bottoms of the waters they frequent.

Ever since ancient times, mystery has surrounded the life cycle of the eel. Eel spawning was never observed, generating a wealth of folklore about how and where they bred. However, research in the 19th and 20th centuries identified that eels are likely to spawn in the Sargasso Sea between Bermuda and Puerto Rico, after which it is assumed that the adult eels die. The larvae drift 6,000km on the Gulf Stream towards Europe in a migration which takes nearly a year, before they enter river estuaries and begin to migrate upstream. Once in freshwater, the larvae metamorphose into 'elvers' (young eels), which locals call 'barley-eels' due to their yellow-brown colour.

Males are thought to stay in the lower reaches of rivers while females travel much greater distances upstream, moving mainly by night and overcoming all sorts of natural challenges to reach even the smallest of creeks. They can move themselves over wet grass and dig through wet sand to reach upstream headwaters and ponds. These river-based eels gradually darken to dark brown/green/black on the back to white/golden yellow on the belly.

After 5-20 years, or perhaps even longer, in fresh water, the eels become sexually mature and, as they begin their phenomenal migration back to the Sargasso Sea to spawn, their colour gradually changes to silvery white, aiding camouflage. As they leave fresh water and enter the sea, their digestive system breaks down, meaning they complete the 6,000km return journey to their spawning grounds without any further intake of nutrients.

The River Glaven

Illustration for Background to the project

The River Glaven (centred approximately TG041415 at the village of Glandford), rises from tiny headwaters in the Lower Bodham/Baconsthorpe area and descends only 50 metres over a curving route of 17km before it meets the sea behind the famous shingle spit at Blakeney Point. 

Its valley is the jewel in the crown of the north Norfolk coast chalk river valleys. Its mosaic of linked habitats make it one of Norfolk's most beautiful and ecologically valuable areas; a wonderful chain of wooded hills created from glacial debris, lush countryside, picturesque flint villages, water mills, country estates, lakes, patches of fen, reedbed, wood pasture, wet woodland and fresh and saltwater marshes.

In character, it is a 'quiet place' with a distinctive character much loved by local people and visitors and a wealth of geological, hydrological and ecological history which provides the context for past and present human habitation and activities.

Wildlife heritage

The Glaven Valley supports a wide range of Biodiversity Action Plan (BAP) priority habitats, including the chalk river, ungrazed fen meadows, clear water shallow lakes and fresh and saltwater coastal marshes, many of which are of national importance and support a wealth of BAP species of plants and animals. These include water crowfoot (Ranunculus penicilliatus var. calcareous), spiked water mill-foil (Myriophyllum spicatum) and breeding and wintering populations of Bittern (Annex II European important species). Other birds that utilise the river's freshwater wetlands include barn owl, green sandpiper and osprey, all listed Schedule 1 species under the 1981 Wildlife and Countryside Act. Water voles (National Biodiversity Action Plan species) are common in many parts of the valley. Otter, eel, bullhead, river lamprey, brook lamprey and white-clawed crayfish are all Annex II species protected under the 1992 European Commission Habitats Directive (92/43/EEC) and the Glaven is an especially important river for having populations of all these species.

In recognition of its value, the river catchment contains, or is partly within the boundary of, key conservation designations including County Wildlife Sites, Local Nature Reserves, RIG sites (Regionally important geological sites), priority habitats under the UK Biodiversity Action Plan, Sites of Special Scientific Interest, the Norfolk Coast Special Area of Conservation, the Norfolk Coast Special Protection Area, National Nature Reserves, the Norfolk Coast Ramsar Site, the North Norfolk Heritage Coast, the Norfolk Coast Biosphere Reserve and the Norfolk Coast Area of Outstanding Natural Beauty. Unusually, the whole Glaven Valley has also been designated a Conservation Area based on the quality of its landscape, character and appearance.

Cultural heritage

The Glaven's river and valley displays a close connection between its wildlife heritage and its rich historical and cultural heritage. Significant archaeological remains establish the presence of Homo sapiens in the Glaven area 5-10,000 years ago, since then they have intermittently occupied the landscape. Several mills along the course of the river have existed since before the Norman invasion so river flows have long been interrupted for industrial purposes. Five of these mills remain today, with one of these (Letheringsett corn mill) still in working order and producing flour.

Baconsthorpe Castle scheduled ancient monument is a 15th Century moated manor house, while Bayfield Hall is a Grade II 18th Century country house developed on the site of a Tudor house and medieval village. It is surrounded by formal woodlands, parkland, meadows and lake which was dug in the late 18th Century for ornamental purposes. A tunnel was added in the late 19th Century to partially divert the river flow around the lake.

Cley-next-the-Sea, a Glaven village in its wider setting

Cley-next-the-Sea, a Glaven village in its wider setting

The lower reaches of the river have had a particularly dynamic history. From the 13th Century onwards, a wide expanse of tidal water between Wiveton, Cley and Blakeney (known as Blakeney Haven) functioned as one of the greatest ports in England. Ships of up to 130 tons unloaded cargoes of fish, spices and coal to be transported inland by wagon. In the 18th Century flood embankments began to infill with sediment, the path of the river changed and narrowed and eventually the port fell into severe decline.

A high proportion of the 7,900 permanent residents share a feeling of ownership of this defined area but understanding of its history and ecology is suffering a rapid decline.

Eels in Norfolk

The mysterious eel

The mysterious eel

Our relationship with eels is a long one and the eel has a major, but largely forgotten, place in Norfolk's rural history. Many of the older farmers, countryman and fisherman tell memorable, sometimes unfathomable, accounts of eels blocking drainage pipes from remote field ponds, eels inexplicably appearing in horse troughs or eels moving through the wet grass on moonlit nights.

We know that eels were caught using fishing spears and weirs during the British Mesolithic period and there is plenty of evidence to show that eels continued to be collected and eaten right up to recent history. In fact the old methods of catching eels were not so different to those used in the modern era. For example the eel fork, a particularly vicious looking spear, was used up until at least the early twentieth century, whilst the basic design of the eel trap has barely changed since the Bronze Age. Indeed the fyke nets, still used today to catch eels from rivers and lakes, are not too dissimilar to traps dating back to 1,100BC, discovered in a recent archaeological dig in Cambridgeshire.

Every north Norfolk village and hamlet would once have had an eel catcher who would have known how to catch them in his own handwoven wicker baskets made from willow and how to tame them to go to sleep in his hands. Villages such as Salthouse, on the north Norfolk coast, were once famous for the amount of eels caught during their annual eel run.

The Blakeney Nature Reserve site warden recounts his father's and grandfather's stories of eel-catching competitions on Blakeney marshes, with people 'babbing' for eels (using a line with bait and tangled thread at its end to entice the eel and then entangle it, allowing it to be pulled in and captured).

Only two local traditional eel catchers survive, both retired as one is well into his 70s and the other, though cagey, is thought to be over 80. They have their equipment and a wealth of stories and, with their families not interested in lives as eel catchers, they are both keen to pass on the traditions to others before they are lost for good.

Historically, eels were seen as a cheap, nutritious and readily available food source and jellied eels became a traditional English dish in the 18th Century. However eels were not just eaten - they were also used to pay for rent or fishing rights and their dried skin (tougher than leather) was plaited into a ring and used for wedding bands and chastity belts.

Project need and opportunity

Today, local, traditional eel-fishing skills have almost completely died out, partly due to a decline in popularity for eel in the British diet and partly due to the catastrophic drop in eel numbers in local rivers. Local children had no experience of elvers or eels. This project changed that, re-connecting eels with the local community and enabling them to re-stock the river.

The Decline of the Glaven Valley eel

Although the Glaven valley remains a high quality environment with strong local culture and identity there are a number of environmental and cultural issues which threaten eel survival. In addition, since the 1970s the numbers of eels reaching Europe, including Norfolk, is estimated to have declined by over 90%. It is likely that there are many reasons for this decline, though the mysterious lifecycle of the eel makes study difficult.

International influences
International effects, beyond the scope of this project, may include overfishing of young eels in the open ocean, parasites such as Anguillicola crassus (which affect the swimbladder that eels rely on to cross the ocean), barriers to migration and natural changes in the North Atlantic oscillation, affecting the characteristics of the Gulf Stream and the North Atlantic drift. Recent work suggests that PCB pollution may be a factor in the decline.
Opportunity: to Increase scientific knowledge about eels.

Local causes
Degradation of habitats and ecology

Over centuries the River Glaven has been modified through a combination of canalisation (widening, deepening, straightening and embanking), drainage, clearance of the floodplain and introduction of structures which regulate water flows, such as mills and weirs.  These works have led to loss of riffle/ pool habitat, loss of bank side wetland habitat and increase in barriers to migration. The severing of the connection between river and floodplain is reducing the ecological quality of adjacent wetlands. Non-native species such as mink, signal crayfish and Himalayan balsam put further pressure on native wildlife.

Eutrophication has affected the River Glaven system with substantial summer growths of 'blanket weed' (filamentous macro-algae). This has the effect of reducing oxygen in the water to the detriment of aquatic wildlife.

Siltation is perhaps the major environmental problem of the River Glaven on a number of defined sections.

Observations by local people suggest that the silt burden of the river has increased substantially over the last 15-20 years. As a result, much of the gravel river bed lies beneath over 50cm of fine sediment. This is encouraging the dominance of a 'silty' aquatic plant flora (particularly Callitriche and Cladophora spp.), increasing in-channel trapping of nutrients and toxic micro-pollutants (e.g. pesticides). These increase turbidity, reduce habitat diversity and availability, reduce reproductive success and food availability and cause the rapid siltation of on-stream lakes. Lower down the river, increasing deposition of river silt in the estuary is one factor threatening the freshwater marshes (Blakeney Freshes) with saltwater flooding.

Opportunity: To improve eel habitat
Opportunity: To enable eel passage at key river structures through introduction of eel passes

Changes to land management and policy

Lower number of workers on the land has resulted in reduced maintenance of ditches and ponds, which used to form good, safe habitats for eels as they matured.

Opportunity: To conduct minor work which will significantly improve the condition of key ditches and ponds

Loss of community connection with the local environment

As the local community is forced to move away from working in traditional trades within the area, the connection to the land is gradually being lost. For now, a bastion of local individuals and voluntary groups fight to preserve this knowledge and pass it on to future generations but they themselves are aging and need support to ensure continuing involvement, education, awareness and access.

Opportunity: To re-connect people with the river, using eels as a focus.
Opportunity: To capture the eel catcher skills, stories and folklore.

Urbanisation and safety concerns

With the increase in technology and electronics and parent's worries about safety, children and young people spend much less time out exploring the countryside. This early connection with the environment, now missing, was once a crucial part of growing up. One university lecturer involved in this project recounts how, as a young lad, his first experience of eels was while poaching on a local landowner's river – luckily, the landowner appreciated his interest and taught him about eels and how to catch them, instilling a love of watercourses which has guided a whole career.

Opportunity: To re-connect children with the river, using eels as a focus, through educational activities.

Why now

There were several compelling reasons to complete this project now:

Aging eel catchers

The local eel catchers are of advanced age and will soon no longer be here to share their experience and stories.

Implementation of the Nine Chalk Rivers project

In July 2012, a partnership of organisations led by the Norfolk Rivers Trust and the Norfolk Coast Partnership won a Catchment Restoration Fund grant of £1.3 million for a three year project to complete defined river restoration projects across 9 of the north Norfolk coast rivers.

The restoration work delivered on the River Glaven helped to improve aspects of river structure and water quality. The Glaven Eel Project built on these gains by funding further improvements specific to the eel.

Eel regulations

The Eel Regulations require the Environment Agency, or property owners with legal ownership of in-river structures, to take actions on 'priority' stretches of rivers to facilitate eel passage. Funding from this project allowed eel passes to be installed on other, 'non-priority' structures significantly ahead of future statutory requirements, enabling a step-change in eel access to the length of the river.

Added value

As with any project focusing on one iconic species, many associated benefits are expected to accrue over time:

  • Support for the bittern population, which consume eels as a major part of their diet.
  • Better spawning conditions for sea trout.
  • Improved river health.
  • Improved connections between the river and its community.
  • Better understanding of river ecology.
  • Inspiration of a new generation of ecologists and environmentalists.