Fauna in a shot glass
What about the fauna in a water body, can be seen in a small sample of water.
Corresponding experiments conducted Danish researchers. The information contained
in the sample DNA evidence thus revealed not only which species occur in a lake or
stream, but also allow an estimate of population density.
"In the water samples, we found DNA from so many different animals such as otters and
dragonflies," said Philip Francis Thomsen from the National Natural History Museum in
Copenhagen. The DNA method could classic surveys, which are time consuming and
require detailed knowledge of species, supplemented, at least, believe the biologist and
his colleagues. This applies especially with regard to animal species that are
represented by few individuals.
And in the aquatic animals to be constantly living with sloughed cells, secretions and
excretions from some DNA to the water. This fact is already being used to detect the
presence of introduced species. The group led by Thomsen and his doctor father Eske
Willerslev went now to the question whether the genetic traces also allow a more
comprehensive faunal inventory.
The researchers conducted traditional inventories of 100 lakes and streams and parallel
DNA analysis in large part, only 15 milliliters of water samples. They focused on six
species - the "primitive cancer" Triops, the aalförmigen weatherfish, great crested newt,
otter, and the Great Schaufelfußkröte and white-faced darter dragonfly species as
critically endangered. Actually voted, the results of the two methods agree well, the
group reported in the journal "Molecular Ecology". Experiments with specifically
occupied pools provided additional confirmation and also showed that a species will
disappear within two weeks of their DNA track.
Basically worldwide consensus prevails on the importance of biodiversity and its
protection, so Thomsen colleague Jos Kielgast with reference to the efforts of the
United Nations. "A basic prerequisite is that we are able to document the status of
endangered species adequately." The DNA method constitutes a relatively simple and
inexpensive approach to control biological communities on a larger scale, said the
researcher. Therefore, it is conceivable in principle that was being used in saltwater fish
DNA contained in future also for the setting of catch quotas.
Research: Philip Francis Thomsen, Jos Kielgast and Eske Willerslev, Center for Geogenetik, Statens
Naturhistorisk Museum, Københavns Universitet, and other
Publication of Molecular Ecology, vol 21 (2), DOI 10.1111/j.1365-294X.2011.05418.x