Sending a message in a bottle is a bit of a folklore for getting rescued from deserted islands but now marine scientists could use a simple bottle of sea water to determine what’s living locally. By using the latest DNA techniques a half litre of sea water can reveal the species of fish and whales living in a locale.
The new technique has been pioneered by researchers at the University of Copenhagen and could be used for both marine conservation and surveying and also fisheries management.
“The new DNA-method means that we can keep better track of life beneath the surface of the oceans around the world, and better monitor and protect ocean biodiversity and resources,” explained PhD student Philip Francis Thomsen from the Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen.
We analysed seawater samples specifically for fish DNA and we were very surprised when the results started to show up on the screen. We ended up with DNA from 15 different fish species in water samples of just a half litre.
The development of the novel DNA monitoring approach was accomplished by PhD student Philip Francis Thomsen and Master’s student Jos Kielgast from the Centre for GeoGenetics headed by Professor Eske Willerslev.
The latest method published online at PLoS One is a further development of the technique that they developed last year with freshwater ecology.
When fish and other organism live in an area of water they leave behind minute traces of their DNA. By recovering that DNA scientists are able to determine the species. The marine environment with its high salt content is a harsher environment that freshwater but the researchers were still able to recover details of 15 species of fish from 0.5 litres of seawater.
“We analysed seawater samples specifically for fish DNA and we were very surprised when the results started to show up on the screen. We ended up with DNA from 15 different fish species in water samples of just a half litre. We found DNA from both small and large fish, as well as both common species and rare guests. Cod, herring, eel, plaice, pilchard and many more have all left a DNA trace in the seawater,” says Philip Francis Thomsen.
Another small sample of sea water also revealed the presence of harbour porpoises leading to the new technique being useful for tracking or surveying marine mammals. It’s not just fish and marine mammals that were discovered in the DNA cocktail. The researchers note in one of their papers that they were able to discover the DNA of 4 marine bird species.
This new DNA technique proved to be at least as good as and in some cases better than traditional fish surveying techniques which uses nets and pots. The big benefit of the new technique is that it doesn’t have any impact on the local environment and can be undertaken anywhere at anytime.
One of the people involved in the study, fish expert Associate ProfessorPeter Rask Møller from the National History Museum of Denmark, thinks the new surveying technique could change the way in which a lot of marine surveying is undertaken. “The new DNA method has very interesting perspectives for monitoring marine fish. We always keep our eyes open for new methods to describe marine fish biodiversity in an efficient and standardised way. Here, I look very much forward to follow the DNA method in the future, and I think it could be very useful to employ in oceans around the world,”