Five reasons why we need the Freshwater Network
1st May 2025
Freshwater Habitats Trust CEO Professor Jeremy Biggs says we need an entirely new approach to reversing the decline in freshwater biodiversity.
Life in freshwater is under severe threat. Globally, these habitats and the plants and animals they support are among the most vulnerable parts of the natural world, prompting widespread calls for new measures to protect them.
We’ve unveiled our strategy to build the Freshwater Network, creating a network of wilder, wetter, cleaner, more connected habitats for wildlife. But why do we need such a radical shift in how we protect and restore the freshwater environment?
1. Freshwater habitats are degraded
Ponds have been lost in vast numbers since 1900, and there have been substantial losses of pond biodiversity in recent decades, even from nature reserves and Sites of Special Scientific Interest (SSSIs).
Our rivers are among the worst in Europe: very widely damaged by pollution and centuries of physical modification. They continue to be degraded by a cocktail of pollutants and other pressures, losing water plants and supporting a fraction of their historic biological riches.
Only 16% of English rivers and canals reach Good or High ecological status in the Water Framework Directive classification. Beyond the channel, about 70% of river floodplains are damaged by intensive land use, drainage and pollution, and are one of the least protected parts of the water environment.
- A pond at Busketts Wood in the New Forest
Lakes are as widely degraded by human impacts as they have ever been. The north of Scotland is now the only region in Britain with larger lakes in good condition. The worst effects of acid rain have probably now passed in the uplands, but lakes have not fully recovered. Since 2010, the proportion of lakes classified as Good or High status under the Water Framework Directive has steadily declined, despite some local improvements from better nutrient pollution control.
Other freshwater habitats, including fens, ditches and headwater streams, are largely unmonitored and are facing the same threats.
2. Freshwater species are declining
Across the UK, habitat loss and pollution continue to drive species declines, with around 1,000 freshwater species now listed as rare or threatened: an alarming 25% of all those assessed.
Iconic species like Atlantic Salmon (Salmo salar), European Eel (Anguilla anguilla), White-clawed Crayfish (Austropotamobius pallipes), Water-violet (Hottonia palustris) and Freshwater Pearl Mussel, (Margaritifera margaritifera) are on long downward trends. Freshwater plant species that were once widespread have become vanishingly rare. Recent evidence from our Water Friendly Farming project shows they have been declining by about 1% every year since 2010 in agricultural landscapes typical of large parts of the lowlands.
Climate change is having a rapid and unpredictable impact, affecting species in different ways. For example, it’s allowing some species of dragonflies and damselflies to spread, while others are declining, with their populations shrinking into ever more northerly areas. With so many of our freshwaters now isolated and polluted, vast regions are now inhospitable to the movement of species.
3. Other efforts are failing
In the UK, we’ve traditionally placed most emphasis on cleaning up pollution first and protecting what is in good condition second. This has led to piecemeal improvements to polluted and damaged sites through point source pollution control, attempting to reduce diffuse pollution and repairing damage to river morphology. Only sewage clean-up has had any large-scale measurable impact for biodiversity.
Despite these efforts, the freshwater environment remains damaged, stressed and threatened.
By safeguarding the remaining high-quality freshwater strongholds and expanding out from them, we can better protect freshwater biodiversity. This approach automatically shifts effort to where the most important biodiversity occurs. It moves us away from an historical focus on just rivers and large lakes, to encompass a much broader range of critical freshwater habitats – many of them small and manageable – where rapid and effective progress can be achieved.
- Water Violet at Sound Common © Anne Heathcote
4. Recovery is possible
Despite the worsening picture for freshwaters, recovery is eminently possible. It has happened for the Eurasian Otter (Lutra lutra) after highly toxic organochlorine pesticides were banned in the 1980s, and for Bittern (Botularis stellaris) as a result of wetland habitat creation.
But to achieve recovery for other species, we need to refocus. We need to put clean water back in the countryside. And we need to expand the range of habitats that we prioritise for creation and restoration.
Small waterbodies include many of the best remaining freshwaters. That’s because their small catchments are more likely to be non-intensively used, so they are better protected from pollution. We know from our own conservation work that it is relatively easy and cost-effective to create clean water ponds, which are quickly colonised by wildlife, including rare and threatened species. We also know that restoring small fens can bring nationally declining species back from the brink.
This shift in understanding of where biodiversity exists on the ground demands a complete reset in how we approach freshwater conservation.
5. We’ve tested it - and it works
We’ve been developing the Freshwater Network for many years. Over the last decade, we’ve carried out Important Freshwater Area assessments to guide our own and others’ conservation work. Important Freshwater Areas are the biodiversity hotspots, which we’re focusing on as we build the Freshwater Network.
Our research, now stretching back nearly 40 years, along with studies by other freshwater scientists, underpins the Freshwater Network. This growing body of evidence demonstrates the power of small waterbodies to reverse the decline in freshwater biodiversity across a landscape. Our study on the Water Friendly Farming demonstration site, for example, found that adding just 20 clean water ponds in a 10 km2 area (doubling the density of ponds) increased whole landscape aquatic plant richness by 16%, and rare plant richness by 80%.
- New clean water ponds created in the Water Friendly Farming project.
We’ve integrated the Freshwater Network approach into our practical conservation work in Oxfordshire, Buckinghamshire, North Yorkshire, mid-Wales and the New Forest. In these regions – and others across the country – we’re focusing on protecting the habitats that we know are rich in biodiversity. We’re then building out from these strongholds by creating and restoring new habitats for species to expand their ranges.
Here are just a few examples of the success we’ve seen:
- The latest monitoring report shows that 84% of pond sites created by the Newt Conservation Partnership are colonised by Great Crested Newts after three or more years. Sites are carefully chosen to ensure ponds will be pollution-free and can act as ‘stepping-stone habitats’ for existing Great Crested Newt populations. The new sites are enabling the animals to spread out from existing hotspots, helping the species to recover and providing resilience for populations.
- Measures we introduced in the Pitsford Water Friendly Farming project saw a 22% increase in the total number of wetland plant species and a 65% increase in the number of uncommon plant species. The measures were pond creation, pond management, and the introduction of flood storage basins, bunded ditches and leaky dams. New clean water ponds were shown to give the biggest boost to plant biodiversity.
- Oxfordshire’s alkaline fens support some of the rarest and most threatened biodiversity in the UK. With a team of volunteers at Hinksey Heights fen, cutting back scrub and reeds that were drying out the habitat and outcompeting sensitive fen species has led to rapid improvements. Over the three hectares of fen we’ve been restoring since 2018, the number of fen plant species has increased by 300%. Through our work, new species have also colonised Hinksey Heights, increasing the site’s diversity of fen plants by 20%. These include the wetland moss Fountain Apple-moss (Philonotis fontana), not found anywhere else in Oxfordshire.
Read our Freshwater Network strategy.