Aquatic & Fisheries Tagging

Tagging Instructions
Measuring sequence and intervals

In order to use your data loggers you need a communication box that works as an interface between the loggers and a PC, and a software for programing the tags and analyzing recorded data.  With the SeaStar software the user sets the start date, start time and sampling interval before first use. Up to seven different intervals can be set for the same measurement sequence, this is especially useful when more frequent measurements are needed at a certain time period. Before releasing the fish, each tag's serial number should be linked to the fish they are attached to with information on size and release site. 

External and internal Tagging

The tags can be attached both internally and externally on the fish. When using external attachment, the tag is fastened close to or in front of the dorsal fin by steel threading. The internal tagging is done by implantating it into the fish. For more detailed treatment of fish and suggestions about fish tagging see the following links:  
                                                                                                                        -Internal tagging of cod
                                                                                                                        -Fish tagging

Internal tagging

After Recapture

The tag will continue recording data until memory is filled or until connection is made for data retrieval. The data remains in memory and can be uploaded even if the battery is empty. All DST's can be re-programmed and reused as long as the battery lasts. When tagged fish is recaptured we advice you to write down pertinent information e.g. where the fish was caught and what size.

The data can then be uploaded using the SeaStar supporting software via the Communication Box. In SeaStar the data can be analyzed both in graph and table and even imported to other softwares such as Microsoft Excel.


Customers can choose their own text on the tags housings. Normally the tagged fish is recaptured by fisheries and it is important that the fishermen can immediately see where to return the tags, usually there is a reward for returned tags. The housing text should contain the following information: owner, address to send the tags, phone number, and reward (if any). If there is space, you should also note on the tag that the finder should write down the recapture site and length of the fish. When using external tagging, the DST tag is easily spotted by fishermen. For internal tagging, a special flexible plastic tube can be fastened to the DST tag for external identification, these plastic tubes come in a variety of colors.


By using the DST researcher can collect valuable information that would otherwise be impossible to document e.g information concerning the environment surrounding the animal, with minimum disturbance to the animal. The tags have been used successfully in recording environmental parameters e.g. temperature, pressure (depth), salinity and tilt of the animal.

The tag can be used for studies:

  • migration 
  • distribution of fish
  • stock assessment
  • vertical and horizontal movements of the fish 
  • feeding and mating behaviour

Equipment for Internal Tagging

In the table below are listed the equipment that the Icelandic researchers have used for internal tagging. If you are not able to get these items in your home country, Star-Oddi can assist you.

 Product                                          Manufacturer  Notes 
 Needle holder             Medicon/Mayo-Hegar1   Used to hold the needle while sewing 
 Needle holder  Medicon/Mathieu1  Used to hold the needle while sewing
 Scissors  Medicon/Iris scissors1  To cut suture
 Scalpel handles   Swann-Morton2  Handle for the scalpel blades
 Scalpel blades  Swann-Morton2   Scalpel blades, 100 pieces
 Surgical suture    Ethicon3  To fasten the tag, dissolves slowly, 12 pieces 
 Surgical suture  Cyanamid/ Dexon II4  To close the cut, dissolves rapidly, 12 pieces
 Auromecin spray    Cyanamid5  To sterilise the wound, 109 ml, IDU-SCRUB: 45%isopropanol, 35% n-propanol
 Sterilising media     Superfos Biosector6 Sterilise the equipment before/after the tagging 
 Trocars   Kruuse8  To do hole through the dermis for the identical tube

1 Medicon eG
2 Swann Morton Ltd
3 Ethicon
4 Cyanamid Medical Device Co
5 Cyanamid Ibérica, S.A
6 Superfos Biosector a/s
7 Ridge Tool Co.
8 Kruuse