An expert team is resurrecting ice age ponds in Norfolk, bringing rare species back from a ‘perfect time capsule’. The two circle-shaped scars of dark soil on a pasture are ghost ponds being brought back to life by an innovative and cheap form of nature restoration.
“It looks awful now. ‘What have they done? It’s a disaster!’” says Carl Sayer, a professor of geography at UCL, who is dancing with glee around the bleak-looking, freshly dug hole. “The colonisation is so quick. Within a year, it is full of water plants. Within two years, it looks like it’s been there forever. It’s a spectacular recovery, and you’re truly recovering ancient assemblages of plants.”
The two ponds returning on farmland are the 25th and 26th ice age ponds to be restored by Sayer’s team in the Brecks, a hotspot for ancient ponds and “pingos” formed by ice-melt 10,000 years ago. Over the past two centuries, thousands of such ponds have been filled in as land was drained and “improved” for crops.
New surveys by Sayer’s team have revealed that 22 of the ghost ponds restored since 2022 now support 136 species of wetland plant. This represents 70% of the wetland flora found in more than 400 ponds on Norfolk Wildlife Trust’s Thompson Common. The resurrected ponds include rare species such as various-leaved pondweed.
The magic lies in a layer of dark, peat-like sediment, which is the old bottom of the pond, formed from centuries of decaying aquatic plants and still full of seeds. “It’s a perfect time capsule,” says Sayer. “It’s dark, moist, cool and anoxic – there’s no oxygen. This is nature’s emergency recovery mechanism.”
One of the pond restorers, Hayley McMechan, is working on a germination trial for her PhD. Sediment of different antiquities from these ghost ponds is being monitored in tanks at Kew Gardens’ seed bank at Wakehurst. It is likely some seeds older than 1,000 years old can still spring to life. “It shows you the resilience of nature – that seeds have evolved to last that long,” says McMechan. “It’s not rewilding, it’s not restoration, it’s resurrection.”
