Permanent ponds

How

Clean water is a vital part of a healthy pond – many of the species that rely on ponds cannot survive in very nutrient rich or polluted water. Buffering ponds in arable areas is therefore essential, and ideally the buffer around an arable pond should be at least 12m wide. If the ponds on your farm have historically been used for cleaning water through silt collection, it is worth considering creating a new pond complex for wildlife and keeping any settling ponds for that purpose. The best place to site ponds is in permanent pasture, however a wide buffer strip planted up with a mixture of robust grasses will mimic this habitat, providing the grassy margins that benefit amphibians as they migrate to and from  water bodies and terrestrial habitat.

The best ponds are often those in full sun, with shallow margins and a varied topography under the surface. These provide the widest variety of marginal and aquatic plant life. Wide (about 50-60cm wide) and shallow margins (about 5-15cm deep), with a shelved profile into a central deeper well area of about 1.5m will provide the most benefit for wildlife. By providing a complex of smaller ponds, as opposed to one big pond, you add additional value as each pond can be slightly different to cater for a wider range of species. Several ponds in a complex provides a greater number of opportunities for species to find the conditions they require, particularly in a changing environment, such as ponds drying out over a dry summer.

When creating a new pond the temptation is to plant it up, however natural regeneration is by far the easiest way to develop pond wildlife, not only that, stocking ponds increases the chances of bringing in invasive non-native (pest)  plants and animals.

Surface invertebrates like pond skaters, whirligig beetles and water boatmen will usually find a pond within a few weeks, with marginal and aquatic plants arriving in a few months. It can take up to a year, but at the end of that time the new pond will look very much like it has been there all along. It is important not to introduce fish and wildfowl to ponds, as this will have an impact on the number of invertebrates and reduce the suitability of the ponds for many amphibians. The larvae of great crested newts are particularly vulnerable to predation by fish and are rarely found where fish are present in ponds.

The best time of year to undertake pond management is over the winter. This should be typically undertaken between 1st November and 31st January inclusive.

Usual management activities needed to maintain a pond are as follows:

• Invasive aquatic plants can sometimes appear in new ponds, so it is worth keeping an eye out for the worst offenders, such as New Zealand pigmy weed and Parrots Feather. Refer to links for more information regarding identification and management.
• If scrub starts to develop around the pond it is worth managing it so it does not shade the pond out – although some dappled shade is good. Keeping the pond open and sunny is very important. It can often be a balancing act to retain good terrestrial habitat (such as that provided by trees and scrub) and to keep ponds open. A good compromise is to retain trees on the northern side of the pond, but keeping the southern perimeter open.
• Reedmace and common reed can often colonise ponds, and they can be very invasive, swiftly out competing other plants particularly in small ponds. It may be necessary to remove both to encourage a diverse pond community, but should be undertaken sensitively and not all in one season.