Most visitors to Shapwick Moor Nature Reserve come for the sweeping views over the Somerset Levels or the chance to spot some of the region’s iconic birds. But beneath the surface of its quiet ditches and seasonal ponds, a hidden world has been coming to light. Over the past seven years, marine and freshwater biologist Dr Nick Sheffrin has been studying the reserve’s wetlands up-close, uncovering a rich community of aquatic invertebrates and several nationally rare species.

Nick’s journey began in 2016, shortly after retiring from a career in education as a biologist and head of science teaching A-level students. Armed with a doctorate in research methods and a lifelong passion for wetlands, he started taking monthly samples from a single ditch on the reserve. What began as a personal project has grown into a treasure trove of data and discoveries.

A reserve like no other

Shapwick Moor is special. Its four miles (6 km) of ditch systems form a unique linear habitat that stays wet year-round, even during drought seasons. Alongside these ditches are established ponds and shallower ‘scrapes’, which dry up in summer and refill in winter.

These habitats have proven to be a refuge for some of Britain’s rarest aquatic beetles. Among Nick’s most exciting finds are the great silver diving beetle (Hydrophilus piceus) and the even rarer lesser silver diving beetle (Hydrochara caraboides). These species are nationally significant and their presence at Shapwick Moor speaks to the quality of habitat the reserve provides. Other endangered beetles have turned up too, showing just how important these small, often-overlooked places can be.

Nick has also been helping to confirm the presence of great crested newts on the reserve. Elusive at the best of times, they have been detected in the surrounding vegetation with the help of specially trained sniffer dogs.

Seven years of data and counting

While some wildlife surveys simply record which species are present, Nick takes a more detailed approach. Every month, he spends around two hours sampling the same spot, counting not just which species he finds, but how many individuals of each. This consistency is what makes the dataset so valuable: it reveals patterns that a one-off survey never could.

“You can see patterns and trends,” he says. “I know what eats what, and maybe there are some links there.”

His findings reveal intriguing ecological trends.

Snail numbers drop in summer, while flatworms and leeches – which like to feed on snails – become more visible, possibly emerging to seek out other food sources. Saucer bugs, which have needle-like mouthparts and feed on beetles, rise and fall in step with their prey. Caddisfly, mayfly and damselfly larvae each peak at different times of year, neatly sidestepping competition with one another. And as cold-blooded creatures, aquatic invertebrates of all kinds become more numerous as water temperatures rise through the warmer months.

Water chemistry matters too – and one of the biggest concerns for wetlands in this part of England is phosphate pollution. “What we've got in the Avalon Marshes is some really good aquatic wetland, threatened by phosphate,” explains Nick, adding that “phosphate itself is not toxic to an animal”.

Phosphate is a naturally occurring nutrient, essential for plant growth. It enters waterways from a range of sources: agricultural fertilisers and livestock, treated sewage, and even the droppings of birds nesting nearby. The problem arises when there's too much of it, fuelling a process called eutrophication.

An overload of phosphate acts like a shot of fertiliser for algae and fast-growing aquatic plants. They bloom rapidly, blanketing the water's surface and blocking out light. When they eventually die back, bacteria get to work breaking down the dead matter, and in doing so consume large amounts of oxygen. The water becomes starved of oxygen, and other pondlife – invertebrates, fish, amphibians – can struggle or die as a result.

Environmental challenges and resilience

Phosphate is not the only environmental challenge the reserve faces. Invasive species and changing weather patterns also have an impact. One example is the American freshwater shrimp (Crangonyx), which has displaced its native counterpart (Gammarus).

Yet, despite all of these pressures, aquatic invertebrate populations remain remarkably stable. “They don’t seem to have been affected by dry summers or phosphate pollution,” Nick notes. “The aquatic environment is quite buffered.”

This resilience owes much to proactive water management. Over the past decade, interventions like sheet dams and flap valves have kept the reserve wetter, while projects such as Wessex Water’s proposals for a new Integrated Constructed Wetland – a purpose-built system that filters water naturally before it reaches the ditches – aim to protect its delicate balance.

Beetles to birds

Aquatic invertebrates might be small, but they play a vital role in the wider ecosystem. They feed bats, swifts, swallows, martins and even hobbies, which hunt emerging dragonflies and damselflies in summer. “There’s food coming out of those ditches for the bird species,” Nick explains.

His work also highlights the importance of long-term monitoring for conservation. “I’ve recorded over 100 species of aquatic invertebrates over the years,” he says. By keeping consistent records, he is helping to build a valuable resource for local conservationists.

A hidden world worth discovering

Nick’s message is simple: look closer. Beneath the surface of Shapwick Moor’s wetlands is a vibrant and intricate world, from rare beetles and delicate larvae to the web of relationships that links them all together.

Whether you’re a seasoned naturalist or a first-time visitor, the reserve offers an opportunity to experience something special. And with guided walks, pond dipping and regular wildlife updates, there is always something new to discover.

Want to learn more or get involved? Visit the Hawk and Owl Trust website for updates on conservation projects and upcoming events.

Transformative Somerset wetland project secures planning permission 

Wessex Water has received planning permission for the creation of a new wetland and grassland site in Somerset. Adjoining the Hawk and Owl Trusts’ Shapwick Moor Nature Reserve, this project aims to provide a significant boost to water quality and wildlife in the Somerset Levels and Moors.  

Large‑scale habitat creation across more than 25 hectares will use natural wetland processes to filter and improve water before it reaches local rivers and internationally important wetlands, helping to reduce nutrient pollution. 

By reducing nutrient loads and enhancing the surrounding landscape, the new wetland is expected to strengthen biodiversity and support species ranging from dragonflies and wetland birds to otters. 

Wetlands that deliver benefits for people and wildlife 

Integrated constructed wetlands bring together water treatment, habitat creation and landscape enhancement in a single, natural system. By reducing levels of harmful nutrients from sources such as agricultural run‑off, septic tanks and domestic wastewater, the new wetland will help protect the delicate ecology of the Somerset Levels, an area renowned for its birdlife and biodiversity. 

Designed to blend into the surrounding landscape, the wetland will help regulate water flow and create a more resilient network of habitats. This approach supports a wider range of species while offering opportunities for people to connect with nature through carefully managed access. 

The project builds on the Hawk and Owl Trusts’ long‑standing conservation work at Shapwick Moor, where monitoring already provides valuable insight into the health of local bird populations and ecosystems.  

Expanding the wetland area will support more comprehensive data collection, helping to demonstrate how nature‑based solutions can improve water quality and biodiversity at a landscape scale. 

What’s next? 

With planning approval secured, construction will commence later this year, followed by seasonal planting and seeding.  

Wessex Water has confirmed long‑term management funding over 30 years, giving the Trust the security needed to plan habitat care, ecological monitoring and visitor access well into the future. This commitment ensures the wetland and grassland can be woven fully into Shapwick Moor’s ongoing conservation landscape. 

The Hawk and Owl Trust aim to submit a planning application for the construction of hides for the observation of wetland birds and badgers soon, and it is hoped that the Hawk and Owl Trust will take operational control of the site in early 2027. 

Transforming the landscape and preserving it for future generations 

The granting of planning permission represents a major milestone in a project that will have long‑lasting benefits for nature, local communities and the wider Somerset Levels.  

As work moves forward this spring, we look forward to sharing visible progress on the ground and, ultimately, to welcoming supporters to experience the new wetland as it comes to life. 

In part 1 of our recent article we explored the wider ecological impact of beavers and how they support diverse ecosystems. Now, we look at their day-to-day habits and local reintroduction efforts.

Living as a family unit, beavers share work and regularly socialise. Beavers are crepuscular (they are active at dawn and dusk), waking to forage, build and repair dams, expand their lodges and move through their territory as the light fades. Observation reveals their persistence, inventiveness and surprising strength; their ability to carry branches larger than themselves and return night after night to refine their dams demonstrates a determination that has those lucky enough to monitor them in awe.

They can also hold their breath for up to fifteen minutes thanks to lungs three times the size of ours, a reminder of just how specialised they are for life in water.

Reintroduction to Norfolk

At Sculthorpe, the Hawk and Owl Trust have helped facilitate the return of beavers. Working with the Beaver Trust, a male was translocated from a wild population in Scotland and paired with a female from a licensed Yorkshire project. Released together into a pond within a 52-acre enclosure, they quickly settled into their new home. Four years later, their family has grown to seven, they quickly settled into their new home.

The enclosure was chosen for its mixture of woodland and wetlands, offering plenty of space and abundant natural food. To understand how the beavers are shaping this landscape, a dedicated team of volunteers monitors their activity through trail cameras. Each week, volunteers walk the enclosure to document beaver structures, felled trees and any changes to the fence line. The attempt to trap kits is made annually for microchipping and health checks, while regular surveys of birds, butterflies, dragonflies and fungi track changes in biodiversity.

Early dividends

Although change occurs slowly, the effects of the beavers’ presence at Sculthorpe Moor are increasingly visible. The enclosure is now a thriving, undisturbed haven for wildlife; an increase in dragonflies, damselflies and froglets have been recorded.

One day a poplar tree, weakened by rising water levels, fell. However, a pair of kingfishers soon took advantage of the new structure, excavating a burrow in the buttress of the fallen tree and benefiting from the larger hunting grounds created by the new wetlands.

Another surprise has been how often the beavers themselves can be seen. Although tours never promise sightings, visitors have enjoyed remarkable views of both adults and kits going about their evening routines.

Overcoming challenges

Not every part of the landscape has been easy to manage. A ditch maintained by the Internal Drainage Board runs through the enclosure, and the beavers were quick to attempt to dam its outflow pipe. Although this caused no problems within the reserve, the ditch needs to remain clear.

To prevent constant dam removal while still allowing beavers to behave naturally, sluice boards were installed to manage water levels. This was a great example of how beaver-related issues can be solved creatively and effectively with simple tactics.

Looking Beyond Sculthorpe

While the Sculthorpe Moor enclosure is just a small contribution to national reintroduction efforts, it is helping build understanding of how beavers shape landscapes when given space to do so. Norfolk’s wetlands are central to the county’s identity, and these beavers offer a glimpse of how similar habitats could be restored and enriched if beavers were able to return more widely.

Looking ahead, the project aims to continue engaging the public, deepening understanding and raising awareness. As the beaver family grows, the hope is to move kits to other enclosures or licensed release sites, supporting beaver recovery across the UK.

How People Can Learn More and Support This Work

Wild beavers in Norfolk remain limited to a small number of licensed enclosures. For those wishing to learn more, the Beaver Trust website offers extensive information about beavers and their reintroduction across the country. Visitors to Sculthorpe can also learn about the enclosure, join guided tours, or attend talks, including an upcoming presentation by the Beaver Trust.

Norfolk now has three beaver enclosures, and supporting these projects, by visiting, attending events or simply learning more about beavers, is an excellent way to contribute to their future.

Although the Sculthorpe Moor enclosure is not open for general access to protect the beavers from disturbance, a small number of guided and private tours provide an opportunity to see them responsibly and learn about their lives.