The rippling impact of ponds on nature

Professor Carl Sayer is renown in academic circles for his work in aquatic conservation, ecology and nature restoration but in his home county of Norfolk, it is ponds with which Sayer’s name is fast becoming synonymous.

‘I grew up in Bodham, just outside Holt. I spent all my youth wandering the area, looking at ponds, hedges, collecting moths. I love the Norfolk countryside to my core,’ says Sayer, who is a lecturer at University College London.

Much of Sayer’s work is focused on his beloved North Norfolk, where he is continuously involved in conservation research projects. From an early age he believed that farming and care of the natural environment can and should go hand-in-hand.

‘My early mentor was a local farmer, Richard Waddingham. He had a load of ponds and he demonstrated to perfection how you could farm ‘hard’ but still treasure the ponds, margins, trackways and lokes as places where nature could thrive. He loved the idea that you could farm for money but also have a natural world ‘yield’ too.

‘Norfolk is a farmed landscape, so we have to farm in a way that is friendly to wildlife. Like Waddingham, a lot of farmers do that already and they get a lot of joy from it. Our job is to get more farmers connected in this way so they the joy of nature as well. We won’t get that by fighting with each other. Farming and conservation must work together.’

While Sayer has a passion for all things to do with nature, when it comes to ponds, his academic enthusiasm for his subject dials up to a fervent desire to resurrect and restore Norfolk’s nature-rich farmland ponds.

‘There are still 22,000 ponds in Norfolk and 9,000 are still missing. I want to see how many we can bring back.’

A pond is a small body of water, usually smaller than its near relative the lake. There are two major differences between ponds and lakes. While lakes are big enough for the wind to move water throughout the depth of the lake, a pond’s bottom-most level is unaffected by the wind. This leads to stillness on the floor of a pond.

The other major difference is the impact of trees: Lakes are not impacted by trees at their edge, while some ponds can quickly become dark bodies of water, starved of light and oxygen by the trees’ foliage. In time this will kill most biodiversity in a pond.

Sayer explains that the scenario of dark, lifeless ponds is what has happened to many Norfolk ponds in the past 50-60 years. Leaves have dropped onto the ponds’ surface, trees and scrub has taken all the light and the ponds have just grown over.

‘For me there are two types of these abandoned ponds: the ghastly and the ghostly. The ghastly are the ponds that now just look like a small woodland in a field. These sometimes have some water in, but they are completely covered over with tree, hedge and scrub. Then there are the ‘ghostly’ ponds, which have been deliberately filled in with soil, hedges, tree trunks and so on.

‘Those ‘lost’ 8-9,000 ponds are all under the ground now. You can see them on old maps and, in most cases you can see them on the ground because they stand out from the rest of a field. The soil may be a different colour, the crop will mature at a different rate, water sits there in the winter. They are usually not great bits of farm land.’

All of which makes perfect sense when it comes to Sayer’s work on ponds in Norfolk. The idea is to turn these under-productive land forms into places that are vibrant and full of biodiversity. He is leading a team that works with farmers and landowners to clear the overgrown ponds of muds,  trees and scrub. Fast-growing trees – such as willow – are cleared and opened to the sunlight. This is known as the restoration of ponds.

The second phase involves resurrection, in this case of ghost ponds. Sayer’s team identifies old ghost ponds and then excavates them back to how they used to look. The excavation follows the sediment lines, because as Sayer points out, if you change the shape or size, you risk breaking through the layer of clay that allowed the ponds to develop in the first place.

Building a new pond is a third option. Until recently Sayer was unconvinced of the benefit of building a pond where there was no tradition of water collection but since talking to the North Norfolk Coastal Group’s David Lyles, he has changed his mind. As he says, ‘When it comes to ponds, there is no more important habitat for wildlife on farmed land.’

For farmers and landowners the good news is that ponds are pretty much self-managing once they have been given renewed or new life. Once the sediment and rubbish above the line of clay has been removed, then the water will fill and nature will very quickly return. For the fast growing trees, clearance every six years or so would be all that was required to maintain good light and oxygen levels.

And there is no long wait for results says Sayer. ’Ponds will colonise extremely quickly. And the really exciting thing is what is lying in the seedbed. We are still doing work on this, but seeds can lie dormant for thousands of years so once you restore a pond, the seeds that grow back are coming back from the past. That means some really old, often locally or nationally extinct, plants can come back into the landscape – that is a source of constant amazement.

‘To my mind this is the most successful form of restoration in freshwater. When we restore a pond, we restore it in its whole catchment. If you are restoring a river, for example, you cannot address things at catchment scale.’

Once a pond is restored, the impact is seen rapidly. The water clears very quickly, meaning dragon flies and beetles will quickly appear. Plant life will emerge within a few months and provide a habitat structure for all manner of insects. Amphibians, bats, small mammals all follow the habitat.

‘In a tiny space, no bigger than the floor of a house, there can be an enormous wildlife impact,’ says Sayer.

To put Sayer’s work to practice, the Norfolk Ponds Project is restoring and resurrecting ponds across the county for the benefit of wildlife. Multiple partners have joined up with Sayer, including the Norfolk Rivers Trust, Natural England, the Wildlife Trust, Norfolk FWAG, AONB Coastal Partnership and various local authorities.

Sayer’s motivation can be traced back to his Norfolk childhood and his words will resonate with anyone who is concerned about the rapid and seemingly inexorable degradation of our natural environment.

‘I’ve been hurting ever since I became aware of nature and what we have done to it. That goes back 30 years or more. I balance that hurt by trying to do good by the environment. I am constantly amazed by nature, it is my featherbed if you like, it keeps happy but at the same time, if I see something bad happen in nature, even small things, I get very upset about it. It is always jabbing at me but if I can feel like I am doing good things, then that helps me on. The more you understand, the harder it becomes, but at the same time the more you love nature and the more you want to do for it.’