New research makes it easier to protect vulnerable species from overfishing, writes Science Nordic based on a study by Professor Einar Nielsen of DTU Aqua, which has just been published in Nature Communications.
“The fishery controls are very interested in finding a method to trace the ancestry of the fish,” professor Einar Nielsen says to Science Nordic: “With our method it’s now possible to take an individual fish and determine its population of origin.”
Until recently it’s been difficult to spot the difference between fish within the same species, due to the similarity of their DNA.
“But instead of studying the entire DNA, we have developed a method where we go in and study exactly the part of the DNA where there is most genetic ‘action’,” says Nielsen to Science Nordic.
Using humans as an analogy, he explains that in order to find out why people have different skin colours, it makes good sense to narrow down the focus and study the part of the genome that deals with pigments. The same applies to differences in Atlantic cod, European hake, Atlantic herring and common sole, which are the four species covered in the study.
With the new method it’s now possible to take an individual fish and determine its population of origin.
If, for example, a fisherman has his boat full of endangered North Sea cod, he can no longer claim that his load consists of the less vulnerable Baltic Sea cod.
Another benefit of the new study, according to Nielsen, is that it’s now easier to ensure that fishermen stay away from small fish. In the Eastern Atlantic, the minimum size for hake is 20 cm, but in the Mediterranean, it’s 25 cm.
Some fishermen get away with catching small Atlantic hake by sending them for sale down to the Mediterranean area, where they meet the minimum size requirements. With the new method, however, fishery controls can see whether the 23 cm long hake on sale down by the Mediterranean actually comes from the Eastern Atlantic, Science Nordic writes.
Further information:
Professor Einar Eg Nielsen, DTU Aqua
een@aqua.dtu.dk
+45 35 88 31 15
The complete ScienceNordic article online:
http://sciencenordic.com/bad-news-greedy-fishermen
About ScienceNordic:
ScienceNordic offers science news from the Nordic countries – in English. It is the a joint effort from two science news services in the region, Forskning.no in Norway and Videnskab.dk in Denmark, who work in close collaboration with partners in Sweden, Finland, Iceland, Greenland, the Faroe Islands and Åland.
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