take cryptical - ocean biodiversity used to mean casting nets using long line from navigation vessels or sending out remotely operated and manned submersible warship . But these expensive methods do n’t tell the whole story . Now , to analyze organisms subsist at unaccessible depths , researchers are increasingly looking at what ’s called “ environmental DNA ” ( or eDNA ) , scrap of genetical fabric floating in clear water , Scientific American reports .
Living organisms , on land and at sea , are ceaselessly leaving behind bits of themselves in their metabolic waste , the cells they slough off , and the scales or haircloth they shed . That cellular detritus gives investigator access to their desoxyribonucleic acid , without really having to pull in the animals themselves . Just filter a sample of water or sediment , and then elicit and magnify the DNA . By matching these bits of eDNA to entries in existing databases likeGenBank , researchers are able to key what ’s present where .
In a2012 study , a squad top byPhilip Francis Thomsen from the Natural History Museum of Denmarkcompared fish inventories created using established method ( trap , nets , and trawl line ) and using eDNA . The latter , which identified 15 metal money , was as good as , and maybe even dear than , the traditional methods when it came to fish diversity . moreover , the team also found that identifiable eDNA disappears in saltwater within a hebdomad , so samples would n’t mistakenly count a metal money that ’s no longer around .
Battelle Memorial Institute ’s John Bickhamand colleagues have also applied eDNA methods in the Beaufort Sea , north of the Arctic Circle . And at theSociety of Environmental Toxicology and Chemistry ’s annual meetingin Vancouver last fall , the team say that this approach will needs interchange “ backbreaking and pricey ” conventional methods in deepwater biodiversity resume , according to Scientific American .
But it ’s not quite quick yet . While Bickham ’s team got gazillion of hits , they could only identify up to three percentage . The rest may amount from coinage unnamed to uncommitted databases , or coinage obscure to science . “ In the deep sea,”Bickham add , “ we ’re back in the 1700s . We have no idea what ’s out there . ” He conceive , however , that eDNA methods will help us catch up .
[ ViaScientific American ]
