Random misinformation

With a bit of time to spare on a Sunday night I thought I’d spend a few minutes doing a bit of ‘myth swatting’: stuff people write on apparently reputable websites that doesn’t really stack up in the real world.

So here we are with a random selection of pondy misinformation:

Dragonflies need marginal plants when their aquatic larvae emerge as adults from the water‘. Not really true: there are plenty of dragonflies and damselflies that will emerge on low growing grasses, including particularly the species that are common in garden ponds like Large Red Damselfly, Common Darter and Broad-bodied Chaser. And of course these are often the same species that are quite happy to walk some distance from the pond, and even head into the bushes, to find an emergence site.

Tap water may be used to fill a pond (the chlorine will quickly disappear)…….‘. Tap water is usually a bad idea because of excessive nutrients, and most water is no longer simply disinfected with chlorine but with a mixture of chlorine and ammonia called chloramines – and these do not evaporate from the water.

Summer is the time for pond dipping…..‘ – Of course you can go pond dipping any time but if there’s one time that is best, it’s spring from about March to May when the greatest variety of animals is still in the pond before they have all emerged as adults. Obvious once you’ve looked in a few ponds.

….and maintenance/disturbance should be kept to a minimum as many species are breeding (in summer, that is).’ I’ve never really fathomed why things living in ponds would be especially sensitive in the summer. And of course quite a few of them are not in the pond in summer.

The most important task in autumn is to keep the water free from decaying vegetation.’ Decaying vegetation is a tricky issue – ponds that are typical garden-pond shaped (i.e. rather too deep for their area) seem to have a tendency to become stacked to the gunwales with dead leaves, which almost inevitably leads to very low oxygen levels. These ponds usually have very limited animal communities (though they may still have breeding Common Frogs and Smooth Newts). But in broad and shallow ponds, which should be better oxygenated, moderate amounts of leaves, twigs and decaying organic matter are perfectly natural, and provide food and shelter for a variety of creatures. In these ponds it’s possible that there will be enough oxygen and biological activity to stop rapid build up of leaf material – though a good long set of observations is still needed to confirm this.

Remove dead and dying foliage regularly and prune back excess growth of submerged plants.’ Over-tidying probably doesn’t do any good for wildlife – it certainly doesn’t happen in nature. And removing submerged plants is likely to be a big mistake – it takes away habitat from otherwise rather barren open water, and leaves the stage free for algae to take over.

Place netting over the pond where practicable as this can help autumn maintenance by keeping leaves and debris from falling in and fouling the water‘. Well, this is only really a problem if you’ve got a pond with a deep – 50 cm – sump. Just possibly a net might be worth it then. But in shallow, well-oxygenated ponds, falling leaves and twigs should be beneficial rather than a problem.

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One Response to “Random misinformation”

  1. Now I am doing it – looking for myths in pond advice « Pond at 38 Nursery Rd Blog Says:

    […] random misinformation highlighted by the garden pond […]

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