Sampling DNA from seawater may be one way to check up on fish and other marine life, according to research. Sequencing fragments of DNA from water 1km (0.6 miles) below the surface can determine the type and quantity of fish present, say Danish scientists.
(From BBC News / by Helen Briggs)– The DNA-based technique could be used for monitoring fish sustainably without having to catch them.
Fish populations are under pressure from over-fishing, pollution and climate change.
Dr Philip Francis Thomsen, of the University of Copenhagen, said the environmental DNA (eDNA) approach was “very universal”, giving information on many fish, including flatfish, sharks and rays, and deep-sea species.
“We are basically doing equivalent to CSI [crime scene investigation] work for a biologist,” he told BBC News.
“Investigating the biodiversity of the ocean by using environmental DNA as a proxy for what is actually living there.
Fish leave tiny bits of DNA in the water during their lives.
The genetic material is invisible to the naked eye, but can be extracted and sequenced, yielding a “DNA fingerprint of the ocean”.
In the study, samples of seawater were taken by scientists during deepwater trawling off Greenland for research purposes.
All but two of 28 different types of fish captured had left traces of their DNA in seawater.
Another three were identified through their DNA alone. These included rare deep-sea species such as the angler fish.
The scientists then looked at two commercial fish species – the Greenland halibut and the redfish – in more detail.
They made a heat map of where most of the fish DNA was found.
Read the full article here: http://www.bbc.com/news/science-environment-37989260