- Lets biologists 'count' animals - not just number of species
- Works on anything from an otter to a dragonfly
- Biologists still currently use 'manual' head counts
- DNA method is as reliable as manual
- In future, could even be used for fish quotas
By Rob Waugh
The DNA traces in a single shot glass are enough to identify not only the species living around a lake - but how many of each animal there are. It works for anything from otters to dragonflies
Up until now, 'monitoring' animals has relied on fairly low-tech methods - finding the creatures and counting them.
It's a method that's changed little in the last hundred years, even if biologists have added GPS tagging and computer monitoring once they've found the beasts.
But a Danish research team has found an incredible short-cut – a lake water sample the size of a shot-glass can contain evidence of an entire lake fauna.
It's so effective in counting not only which creatures are present, but how many, that the researchers think that in future it may even be used to count fishing quotas.
Researchers at the Natural History Museum of Denmark found that rare and threatened animal species could be monitored simply by taking note of the DNA traces in fresh water environments.
'In the water samples we found DNA from animals as different as an otter and a dragonfly,' says Philip Francis Thomsen.
'We have shown that the DNA detection method works on a wide range of different rare species living in fresh water - they all leave DNA traces in their environment which can be detected in even very small water samples from their habitat.
By studying the fauna of one hundred different lakes and streams in Europe with both conventional methods - counting individuals - and the new DNA-based method the research team documents that DNA detection is effective even in populations where the animals are extremely rare.
The study also shows that there is a clear correlation between the amount of DNA in the environment and the density of individuals meaning that the DNA detection method can even be used to estimate population sizes.
Read more: http://www.dailymail.co.uk/sciencetech/article-2073170/A-glass-water-traces-EVERY-living-thing-lake--change-way-monitor-animals-forever.html#ixzz1gva9xqr3