Just in case you needed another reason to love dogs.
DNA sequencing means a scientist can take a bucket of seawater and ID every fish in the area. Now we need a universal 'biobank' of samples to make a truly powerful environment monitoring tool.
Scientists are using environmental DNA to compile a census of life in Loch Ness and to establish if there is any scientific basis for the centuries-old monster legend.
We cannot spot every shark in the ocean. But we can detect their 'environmental DNA'.
Animals shed bits of DNA as they go about their lives. A new study of the Hudson River estuary tracked spring migration of ocean fish by collecting water samples and seeing whose DNA was present when.