Wildlife ponds
Benefits to wildlife
During the past 100 years, the UK countryside has lost almost 70% of its ponds, making garden ponds of increasing value to wildlife. The creation of new ponds has never been more important.
What can you expect to see?
Our pond favourites - frogs, toads and newts - will all use quite small bodies of water to breed in, provided there is sufficient deep water (at least 60cm/2ft at the deepest). Fish predate on many other forms of pond life and their introduction is best avoided. However, there are exceptions; toad tadpoles, for example, are unpalatable to fish.
Larger ponds may attract mallards, moorhens and coots, as well as swallows and housemartins which pick off insects from above the water surface and collect muddy soil for nest building. The grey heron can be a regular visitor to even the smallest pond.
Smaller inhabitants of your pond will be numerous. Most ponds will have pond skaters,
water boatmen, water beetles, snails, mayflies, caddis flies, damselflies and dragonflies.
Decking over a section of pond will give good wildlife watching opportunities but ensure children are supervised.
Pond type
Wildlife appears to make no distinction between natural and man-made ponds. Instead, shape is more important. Try to incorporate at least one side of the pond with a long, shallow slope. This is referred to as the ‘drawdown’ zone since it is the difference between the winter and summer water levels. A large drawdown zone not only allows easy access for wildlife into and out of the pond, but is a damp ground habitat vital for many beetles, bugs and flies. Butyl liners are the easiest way to create a slope. Pre-formed plastic or fibreglass ponds without this feature are best avoided.
Make straight sided, formal ponds more wildlife friendly by placing a wooden or stone ramp in one corner. The ramp allows ducklings, amphibians and unfortunate hedgehogs a way onto dry land.
Pond size and siting
Wildlife can be found in ponds of all sizes. In general, however, the larger the pond the more wildlife you can expect to attract. A depth of 20-60cm (8-24in) varied across the pond will suit the majority of pond flora and fauna.
Shade over at least part of the pond is beneficial for keeping down algae and is tolerated by many pond plants and animals. Siting a new pond to incorporate shade should therefore be considered.
Pond planting
First, you do not have to plant up your pond at all. Natural colonisation by plants and wildlife usually happens quicker than expected, though may take longer in sites isolated from other ponds.
Planting up the pond will give more control over the appearance and is preferred by many. Marginal plantings (left) provide important areas of cover and plant stems at the water’s edge are needed for emerging damselfly and dragonfly nymphs. Aim to achieve 65-75% surface coverage with floating aquatics. Some submerged planting (often called ‘oxygenators’) (right) is equally important. Use native plants where possible and avoid known invasives such as fairy fern (Azolla filiculoides), New Zealand pygmy weed (Crassula helmsii), parrot’s feather (Myriophyllum aquaticum) and floating pennywort (Hydrocotyle ranunculoides). Landowner’s permission must be sought when collecting plants from local ponds and ditches.
The placing of dead branches into the pond enriches the habitat considerably, as do tree roots growing into the pond. Resist removing overhanging branches that naturally dip or fall into the water.
Pond maintenance
Topping up
Don’t be too hasty to top up the pond during dry weather in late summer. Seasonal ponds are a natural feature in the UK, filling up in winter and occasionally drying out in long, hot summers. This seemingly inhospitable environment can actually favour certain animals. Newts, for example, are able to survive in the mud during dry months, unlike fish who predate on newt larvae. Where additional water needs to be added try to use rainwater. Tap water should be a last resort.
Weed and algae control
Contrary to popular thinking, extensive open water is not essential for a good wildlife pond. Most pond creatures prefer an underwater maze of plants in which to hunt, hide, feed and breed. Where necessary, rake off or pull out vegetation to maintain the 25-35% open water optimum. Ideally remove vegetation in a wedge shape to avoid removal of plants at only one depth. Where algae is excessive, float pads of barley or lavender straw in the pond from spring to late summer, increase shade, avoid fertiliser use in or near the pond and keep fish stocks to a minimum.
Silt
Silting up is considered by many to be a bad thing. However, the natural progression of a pond is to fill in until it becomes wetland and each stage of this process has its own unique wildlife. If sediment removal is considered necessary to maintain a pond (left), try to remove only half at one time in order to minimise the loss of mud dwelling creatures and their habitat. There is no ideal time for such a job, though late summer when the water is naturally at its lowest is considered the most practical period.
Recommended reading
The Pond Book: A Guide to the Management and Creation of Ponds published by Pond Conservation, 1999, ISBN 0-9537971-0-4, website: www.pondconservation.org.uk