Rural: Downland newts hope for small pond success

The great crested newt population of the South Downs has fallen dramatically. But restoring some of the Downs' ancient dew ponds looks set to provide a remedy, as Sarah Lonsdale discovers.

The dew ponds of the South Downs have been there ever since the great chalk escarpments were first grazed, hundreds of years ago. The grassy Downs are prime grazing land except for one vital fact: being made of porous chalk, they offer no natural water supplies for sheep and cattle.

Farming communities scoured out the 50-foot-wide saucers of earth, lined them with clay and straw and let the rains do the rest. Before the war, there were hundreds of the great, wide ponds, some up to 8ft deep, crowning the tops of the Downs. Kipling, describes them in a poem he wrote in 1902:

We have no waters to delight our broad and brookless vales

Save for the dewpond on the height

Unfed which never fails

Where by no tattered herbage tells

Which way the season flies

Save for the close bit thyme which smells

Like dawn in paradise.

Today, only a few dozen remain, of which only about a third are watertight. And although sheep and cattle still use the ponds, the needs of grazing animals are now met by modern pumps and tanks.

The existing ponds are home to a variety of rare amphibians and other species, including the great crested newt and the odd little fairy shrimp, admired by scientists for being a living fossil that is unchanged in size and shape from its ancestors found in rocks hundreds of thousands of years old.

This autumn and winter, Charlie Cain, a warden with the National Trust, will be restoring three dew ponds to their original glory in the hope that these rare species will continue to find homes on the Downs. "We could restore them using concrete, but I prefer the original method," he says.

After scouring out a wide saucer shape, traditional dew ponds were created by lining the hollow with a layer of burnt lime to prevent worms coming to the surface and puncturing the clay. Then alternating layers of straw and clay were laid, ending with a final layer of clay about 1ft deep. This was then beaten down to about 6in deep. Dew ponds for cattle were then lined with lumps of flint to prevent the heavy animals from puncturing the lining.

Because of the dew ponds' enormous significance in terms of livestocks' livelihood, they were guarded jealously by the shepherds. Older members of the local downlands farming community all talk of a row between two shepherds on the top of New Timber Hill at the turn of the century, which ended in one shepherd taking a pickaxe to another shepherd's pond. It has been dry ever since. Today the former pond is a simple hollow in the ground, home to coarse grasses and a few bramble thickets. In a few months' time however, after Charlie Cain's work, it will hold water again.

"Restoration of the dew ponds is vital for the newt population," says Dr Trevor Beebee, reader in biochemistry at Sussex University. "The ponds are a good habitat for the newts, but because people have been dumping goldfish and carp in some of the ponds, the newt population has fallen drastically over the past 20 years." He says that the number of ponds where this newt, the only British amphibian to be on the EU's habitat directive, is found, has fallen from nine to three.

The fairy shrimp, another protected species, exists only in so-called temporary ponds and pools, because fish feed on the larvae. Its habitat is under threat from development and there are only 11 known colonies of the shrimp, one of which is in a dew pond on the Downs. This represents a huge decrease, from the 80 pools it was found in at the turn of the century.

"Not only do the dew ponds need to be restored to support these species, but the land around them should remain grass and scrub, not be converted to arable, which is happening in a lot of areas on the Downs," says Dr Beebee. "Perhaps once the ponds have been restored there should be a sign put up forbidding the introduction of fish."

Dew ponds have long held a fascination for people. In 1811, an agricultural historian by the name of Farey wrote: "The farmers and inhabitants set great store by certain ancient ponds or meers of water which rarely or ever fail, yet few have any perceptible stream running from them - many of them are less than a rood in extent and generally are but a few feet deep in the middle. It seems to me that most or all of them are the work of art ... The period when these ponds were made is probably very distant, the tradition even of which is lost."

Fortunately for the ponds of the Downs, there is enough literature for Charlie Cain to be able to re-create the traditional pond linings, with money from the National Trust and the Environmentally Sensitive Areas Scheme. "The trick is to finish them before the spring rains so they get a chance to fill up," he says. "With any luck we'll have a few more newts and fairy shrimps up on the Downs by next summer."