Two more salmons recaptured! » News

The Institute of Freshwater Fisheries recently caught two salmons which had migrated from sea back to the river. The fish were internally tagged with DST micro tags in the spring of 2006, when they were smolts. The tags had recorded depth and temperature every hour for the whole period, or 15 months. The project is unique as it captures the whole sea migration route of the fish, using the smallest depth-temperature tags available on the world market.
The institute has tagged sea-migrating smolts both in 2005 and 2006, and plan to continue doing so in 2008. The smolts were specially brought up in a hatchery for the tagging project. Five of the salmons were recaptured in 2006, but with recent addition of two more, a total of seven fish have been recaptured with the micro tags. More salmons are expected to be recaptured this summer.
By comparing the temperature data from tags to sea surface temperature obtained by satellites, it is possible approximate the geo-location of the fish, at different times.

Average sea surface temperature (from satellite data) during one week in November.