Image: The tag has been attached to 6 large cod for a few months. Photo: Greenland Institute of Natural Resources
Next week cod fishers in Nuup Kangerlua should keep an eye out for the so-called satellite pop-up tags, which scientists from Pinngortitaleriffik have attached to large Kapisillit cod. The pop-up tags have been programmed to fall off on 15 October 2018. In June this year, six cod were tagged with pop-up tags, and the tags are expected to be floating around in the fjord, as soon as they have detached from the cod in the middle of next week. One tag has already been handed in by a longline fisher, after he caught one of the tagged cod. The tags store important information on the life of the cod. Information that will help improve the biological advice. There is a reward of 500 DKK per tag – and 1,000 DKK, if you hand in both tag and the cod that the tag was attached to.
Much information in one pop-up tag
Tagging cod has taken place over the last 100 years. Over time, more than 125,000 cod have been tagged with a small rudimentary plastic tag, and out of these 20,000 have been recovered. The simple plastic tags have supplied us with great knowledge on cod stocks, the migration routes, spawning area and much more. Yet, this summer’s tagging with the so-called pop-up tags is one step further from the plastic tags – or rather many steps further. Every fifth second, the pop-up tags store information about temperature, depth and light. It is the first time that tags of this type have been attached to cod in Greenland, and the biologists hope that the result will be greater knowledge on where the large cod go after spawning, which depths and temperatures they prefer, as well as their migration patterns – do they swim in and out of Nuup Kangerlua and if so, when?
All the information help future-proof the development of the cod stock, so that the stock can be exploited reasonably and sustainably. Greater knowledge is vital for giving optimal biological advice.
Watch a video about the tagging of cod here…