Plant discovery shows the power of new ponds to save rare species

20th June 2023

The discovery of a rare plant, which is extinct across much of central England, shows the power of new ponds to bring threatened species back from the brink, according to national wildlife conservation charity Freshwater Habitats Trust.

The Red List species, Lesser Water-plantain (Baldellia ranunculoides) was extinct in Oxfordshire until it appeared in a new pond created on Otmoor SSSI near Oxford in 2000, where it is thought to have germinated from the seedbank. Now, the plant has spread to a second location in the county, thanks to new clean water ponds created just three years ago by the Newt Conservation Partnership. The Freshwater Habitats Trust team believes it is likely to have reached the new pond when a muddy seed was carried on the foot of a Mallard, or other bird.

Freshwater Habitats Trust Technical Director Penny Williams made the discovery at Whitecross Green Wood, a site near Bicester, which is managed by Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust. She says: “This is such an exciting find! It shows that if we just create high quality new ponds, rare species can sometimes save themselves.”

Aerial view of plant with long pointy leaves and very pale pink flowers in mud.

Lesser Water-plantain has declined rapidly over the past 30 years due to poor water quality and habitat loss. A herbaceous perennial, it grows around the edges of ponds and produces small, pale lilac flowers, each with three petals. It is easy to identify because its lime-green leaves have a delicate coriander scent.

Professor Jeremy Biggs, CEO of Freshwater Habitats Trust, shared the discovery for the first time in a talk today (Tuesday 20 June) at the Symposium for European Freshwater Sciences in Newcastle. Speaking to an international consortium of freshwater specialists, he highlighted the multiple benefits that ponds created by the Newt Conservation Partnership are delivering for wildlife.

The Newt Conservation Partnership is a community benefit society run by two wildlife conservation charities: Freshwater Habitats Trust and Amphibian and Reptile Conservation. It creates aquatic and terrestrial habitats funded through the NatureSpace District Licensing Scheme for Great Crested Newts.

Freshwater Habitats Trust surveyed wetland plants in 25 new ponds created by the Newt Conservation Partnership between 2018 and 2020 in Oxfordshire, Buckinghamshire and Bedfordshire. The aim was to assess whether the ponds have a wider conservation value, in addition to creating high quality habitats for Great Crested Newt, a European protected species.

With an average of 15 plant species in each pond, the waterbodies were found to feature double the number of plant species of an average English countryside pond. The survey recorded 73 wetland plant species in total, many of which are uncommon. These include some remarkable finds including the first Bedfordshire record for the carnivorous plant Greater Bladderwort (Utricularia vulgaris) which was present in two adjacent ponds, and a total of five species of Stonewort – ancient aquatic plants, which only grow in clean water.

Penny Williams adds: “We’re facing a biodiversity crisis and research suggests that freshwater species are particularly hard hit. Declining water quality and loss of suitable habitat means we’re at risk of losing many aquatic plant species. Here, though, we have a wonderful example of how newly-created ponds are supporting a once-extinct plant to spread naturally through the wider countryside.

“It helps that the ponds created by the Newt Conservation Partnership use evidence-based design principles that we’ve developed over more than 35 years. It is particularly vital that the ponds have clean water: something which is helped by their semi-natural surrounds.

“One of the exciting things about making new ponds is that you just can’t predict what will appear. This is one of an increasing number of examples that shows the restorative powers of pond creation. Essentially, creating new ponds is helping rare species to save themselves. Ponds are generally ignored when we look for solutions to the biodiversity crisis, but we now believe they are a quick and effective tool that we can use to help reverse the decline in freshwater wildlife.”

Muddy ground shown from above with plant growing in it

Previous research from Freshwater Habitats Trust and partners has demonstrated the importance of clean water ponds for biodiversity. A paper published in the journal Biological Conservation in 2020, based on a nine-year study, showed that creating new ponds can increase wetland plant species in a landscape by 26 percent and triple the number of rare plants.

Newt Conservation Partnership CEO Dr Pascale Nicolet says: “The results of our survey show that the clean water ponds we are creating through the Newt Conservation Partnership and NatureSpace District Licence Scheme are not only delivering for Great Crested Newt but are supporting freshwater wildlife as a whole, including many rare species.”

Freshwater Habitats Trust CEO Professor Jeremy Biggs adds: “Because of their small size, ponds are typically overlooked and undervalued but we now know they are critically important for biodiversity. In fact, at landscape scale, they support more species than larger waterbodies, including rivers and lakes. This is why it is vital that, to reverse the decline in freshwater biodiversity, we protect the whole freshwater environment. And this is the approach we will take as we build the Freshwater Network and create wilder, wetter, cleaner, more connected habitats for wildlife.”