THE BIG POND DIP - results from the 2009 survey
The Big Pond Dip was started by Pond Conservation in 2009 to gather information specifically about the wildlife of garden ponds - particularly to help improve advice about their design and management.
We had a great response to the survey with loads of interesting new information. The main results are summarised below and the full report will be posted shortly.
The Big Pond Dip is running annually and, in 2010, is being carried out in association with the OPAL Water Survey. Year 1 of the Big Pond Dip was in effect a pilot - now, as we scale up in 2010, we'll be further testing the findings of the first year of survey, identifying the key factors in making really good wildlife garden ponds.
Pond Conservation has also been closely involved in research to assess the condition of ponds in the countryside, with the Centre for Ecology and Hydrology, funded by Defra.
The 2009 Results
In the first year, the main findings about the wildlife and management of garden ponds from the Big Pond Dip were:
The condition of garden ponds as wildlife habitats
About one in ten ponds were in ‘excellent’ condition, with virtually all the animal groups that should be present in a healthy pond.
A further third of ponds were in the ‘good’ category, with more than half of the animal groups expected in a healthy pond.
About half of all ponds were in poorer condition, but even these ponds still provided useful habitat for amphibians and aquatic invertebrates.
Wildlife in the ponds
- More than half of the ponds surveyed were visited by dragonflies or damselflies.
- Three quarters of ponds had water snails, water beetles and pond skaters.
- Virtually all ponds were visited by amphibians and, in around 60%, amphibians were breeding.
Common frogs accounted for most records, but four other species of amphibian were also present: Smooth Newt, Palmate Newt, Great Crested Newt and Common Toad, of which the most commonly seen was the Smooth Newt.
Depending on which estimate of garden pond numbers you use, that might mean somewhere between one and half to two and a half million breeding sites for amphibians in gardens.
Management of the ponds
- More than half of the ponds were in part filled by tap-water which in many places, especially the south, introduces pollutants.
- Most ponds were quite deep with a maximum depth of more than 30 cm.
These two factors probably reduced the variety of wildlife seen in the ponds.
On a positive note:
- The survey results showed that the more different types of plants that were present in the pond, the greater the variety of animals present.
Everyone knows that plants are an important part of the habitat for animals in ponds. But the survey results showed specifically that, if you can ensure that your pond has all three main growth forms of wetland plants: marginal, floating-leaved and submerged - it will support a greater variety of wildlife.
Fish
A quarter of the ponds in the Big Pond Dip contained fish and these give us some of the most interesting results so far, since it is often assumed that fish and wildlife are incompatible:
- The fish ponds contained as wide a variety of invertebrate animals as ponds not containing fish
- Amphibians were just as likely to breed in ponds with fish as those without – although we do have to note that the survey didn’t tell us anything about how many young amphibians finally emerged from the fish ponds.
It seems likely that fish ponds would produce fewer young amphibians than fish-less ponds because, except for toad tadpoles, fish eat amphibian larvae
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