How to Pond Dip Safely and Identify What You Find

A pond is the busiest place in any wetland, and a net plus a white tray will show you more of it in twenty minutes than a year of watching from the bank. Pond dipping is cheap, simple and endlessly absorbing — but it does involve deep water, slippery margins, sharp mouthparts and animals that need to go back promptly. Done properly, everyone comes out ahead, including the pond.

Kit that earns its place in the bag

You do not need much, and most of it lasts for years. The one piece worth spending a little more on is the net: a flimsy toy will fold the first time you drag it through weed.

• A fine-mesh net. A proper pond-dipping net with a long handle lets you reach past the bank without leaning. Mesh fine enough to hold a water flea, sturdy enough to survive a reed bed.
• Two white trays. White gives contrast, so small pale animals stop vanishing against the plastic. A shallow tray is better than a deep one — less water, more visible.
• A pipette, a plastic spoon and a soft paintbrush. The spoon lifts things out, the pipette catches the tiny ones, and the brush nudges delicate nymphs without squashing them.
• A hand lens or magnifier box. Ten times magnification turns a dull brown blob into a caddisfly larva with visible gills.
• A bucket of pond water. Filled at the pond, never from a tap, for rinsing the net and topping up trays.
• Wellies, a notebook and pencil, an identification guide or a phone. And a spare pair of socks, honestly.
• Soap or hand gel and a couple of plasters. You will be handling pond water, and you will get wet.

Staying safe at the water's edge

Most pond dipping accidents are the boring kind: a boot full of cold water, a scraped shin on a hidden brick, a child who leans a little too far. Bank edges are often undercut, and what looks like solid ground can be a floating mat of weed over a metre of silt.

Never dip alone, and never let children dip unsupervised — stay within arm's reach of anyone under about ten. Test the depth with a stick before you commit your weight to the edge, and keep off steep banks altogether; work from a flat, grassy spot instead. Wade only if you know the pond and the bottom is firm, and remember that wellies fill fast and make swimming much harder. Life jackets are sensible for children on any open water.

Pond water carries bacteria, and cuts and grazes are a way in. Cover broken skin with a waterproof plaster, keep hands away from your face, and wash properly before eating or drinking. Leptospirosis, sometimes called Weil's disease, is uncommon but worth knowing about: if you become unwell with flu-like symptoms in the weeks after contact with fresh water, tell a doctor that you have been in a pond. Do not drink pond water, and stay out of any water with a thick green scum or a paint-like bloom of blue-green algae — that is one to walk away from, and to keep dogs out of too.

Catching and handling without harm

Work the net through the water beside weed beds rather than ploughing through the sediment. A slow figure-of-eight just above the bottom, or a gentle sweep alongside reed stems, gathers plenty. Heavy dredging through mud kills things you never see and wrecks the habitat you came to look at.

Lift the net, turn it inside out over a tray of clean pond water, and jiggle it gently. Then put the net down and look. Moving animals give themselves away immediately; the still ones need patience.

Handling is where good intentions go wrong. Use a spoon or pipette rather than fingers — dry, warm skin damages soft-bodied invertebrates, and a few residents can give you a nip worth remembering. Great diving beetles, water scorpions and backswimmers all have a decent bite. Keep trays in the shade or under a jacket, never in full sun, and do not overcrowd them. Most creatures cope with fifteen or twenty minutes in a tray; much longer and the small ones start to suffer from warming water and low oxygen. If you want a closer look at something fragile, use a magnifier box with a little water in it, then return it.

Identification: start with three questions

You do not need to name everything. Getting to a group — beetle, bug, nymph, snail — is a perfectly good result, and it teaches you far more than guessing at a species.

How does it move?

Whirligig beetles spin in circles on the surface. Pond skaters row across it with long middle legs. Water boatmen swim with oar-like back legs, right way up and pale underneath; backswimmers do it upside down and look dark, and they bite. Anything that jerks forward in hops across the tray is probably a water flea or a small shrimp-like animal.

How many legs, and how many tails?

Count the legs first. Six legs means an insect, whether adult or larva. More than that, and you are looking at something else — a water louse with its many pairs of legs, or a freshwater shrimp, which lies on its side and curls.

Then count tails at the back end, which is the quickest way to sort the nymphs. Three long, leaf-shaped tails means a damselfly nymph, slender and slow. Three thin, hair-like tails with gills down the sides of the body means a mayfly nymph. A stout, broad-bodied nymph with no visible tails is a dragonfly nymph, and it will move by suddenly jetting water from its rear. Two tails usually points to a stonefly, more often found in running water than still.

What is it wrapped in?

Caddisfly larvae are the easy win. Many build cases from sand grains, twigs or plant fragments and drag them along, retreating inside when you lift them. Others are free-living and spin silken nets. Snails divide simply: a tall spiral is a pond snail, a flat coil is a ramshorn, and a small left-handed shell that seems to hang upside down is a bladder snail. Flatworms glide like ribbons across the tray; leeches stretch and contract; water mites look like tiny round beads with legs.

Leaving the pond as you found it

Tip everything back at the exact spot you took it from, not somewhere convenient. Moving animals between ponds spreads disease and invasive species, and it is one of the easiest mistakes to make. Check the net rim and the tray corners for stragglers first, and give the tray a final rinse in the pond before it goes in the boot.

Then dry your kit. Damp nets and trays carry fragments of invasive plants and animals between sites, so let everything dry thoroughly in the sun before the next visit. Note the date, the weather and what you found — a few years of those notes will tell you more about your local pond than any book. And if you want to dip on a nature reserve, check first: many ask visitors to join an organised session or to work only in set areas, which is no bad thing when someone who knows the site is pointing out what is in the net.

Photo: Pix-Off / Pixabay