As fishkeepers, have you ever wanted to give something back to the wild? Jeremy Gay explains that you can, and you can do it in the comfort of your own garden.
Our aquatic addiction makes us nature lovers by default, but fishkeeping’s eco-credentials are difficult to defend at times, with so much single-use plastic, air miles and energy consumption. So, if you want to help the planet’s wildlife but aren’t directly involved in endangered fish conservation there is another way. Build a wildlife pond.
Building a wildlife pond is just about the most eco-friendly aquatic project you’ll ever embark on. It’s cheap, easy, doesn’t use any electricity yet does huge amounts for wildlife, the environment and maybe even your wellbeing. Wildlife ponds are decorative, educational, and provide havens for both aquatic and terrestrial wildlife, be it flora or fauna, amphibian, bird, mammal or invertebrate. There is no better way of giving something back to the environment while being able to enjoy the water at the same time.
Little and large
Wildlife ponds can range from washing up bowls to lakes, and any water in the garden is better than nothing, but upwards of a metre across is a good start. Aesthetically, all ponds shrink once filled and planted, with anything less than two metres being classed as a small pond and two to four metres being medium-sized. The larger the pond, the more biomass of plants and animals it can support. So bigger is actually better.
But unlike a fish pond, deeper isn’t necessarily better with a wildlife pond. Our imported pond fish need a water depth of over 60cm to enable them to hibernate in the 4°C thermal layer at the bottom of a pond if it freezes over. And ornamental carp like koi, being even bigger fish, need deeper water — ideally 120cm deep in order to exercise, develop the right body shape and grow.
This is one project that won’t be built around the needs of any fish first, however, and experts have found that the greatest abundance of life in natural ponds inhabits just the first 10cm of water depth.
If you want to go deeper you can, but for a wildlife pond plan for a large proportion of it to transition from 0-30cm with a gradual incline. It means less digging too, and although yes, it risks freezing, our British native pond life is adapted to it and survived millennia of winter cycles just fine before we humans first set foot on British shores. They’re adapted to survive.
No flow, no features, just as nature intended.
The right position
In nature, water will collect at the lowest place in the ground so if you have a natural dip in your garden that’s a good place to plan a pond. But the most productive natural ponds are also solar-powered and if you imagine a lowland marshy wilderness there are few trees because of the water. This means that again (unlike a standard fish pond,) it is okay to position a wildlife pond in full sun as pond plants can then proliferate, locking up carbon and nutrients, but also the pond edges will warm more quickly, making them perfect for tadpole development and the microflora on which they feed. Natural ponds also occur in shady forests but you’ll note the lack of aquatic plants growing there and they are less productive
as a result.
Shallow ponds in full sun are everything we say not to do with a fish pond, but wildlife ponds and fish ponds really are chalk and cheese, with most of what we think we know about a healthy pond turned on its head. And there’s more.
Keep it grounded
Forget what all the books, websites and gardening programs tell you; a wildlife pond must be at ground level. Creatures have to be able to crawl in and out from insect larvae to newts, froglets and hedgehogs. Build a ‘wildlife pond’ in a half whiskey barrel and the only wildlife thriving, as a result, will be mosquitoes. And it has to have ease of exit too otherwise you risk drowning wildlife. Even frogs can drown in ponds with steep, vertical walls. Another reason why that shallow incline is ideal.
Build a beach
Building a nature pool is one time when it’s ok to fill that shallow area with pebbles, aquatic compost or even aquarium sand. Pebble lined ponds can look a bit artificial to some but British wildlife seem to love that shallow transitional pebbled area, from insects to toads and bathing birds. And as a wildlife bonus, those stones warm up in the sunshine forming basking areas and staying warm long into the night. And by virtue of our pond not containing any fish, a soil or sand area won’t get stirred up.
Lay your liner flat over the hole and pin it in place with heavy objects. Fill the pond in the centre and work the liner into shape.
A spade is all you need to get started but if you have one, use a spirit level too. The aim is not to have any pond liner showing at the end so make sure the area you dig has a level edge so that you don’t have a big chunk of exposed pond liner at one end. If there’s a lawn there, dig up the turves and save them for later.
Dig the pond so that it is like a satellite dish in profile or a wedge of cheese. It doesn’t have to be round, it can be any shape and even a formal triangle, as long as the edges are shallow for wildlife to enter and exit. Work out where the sun will hit the pond and try to make the beach area south facing to receive maximum solar radiation.
You don’t have to create that one deep area in the way that you do for fish and filter pumps so you can even be brave and create an island or sand bar in the pond. The more habitats and features you create, the more versatile the pond will be for the myriad of wildlife. Make a mini, natural Center Parcs for aquatic life and they’ll instinctively want to holiday there.
Once dug, rake it to remove any sharp stones and if there are trees nearby, chop the roots back so they don’t pierce your liner in the next few years. You can then line the ground with sand or old carpet, but purpose made underlay is available and will help protect the all-important pond liner. Underlay is inexpensive so invest now, set it and forget it.
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