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TAGGED FISH RECAPTURED AFTER THREE YEARS

tagged-fish-recaptured-after-three-years

Tagged Fish Recaptured After Three Years

Two fish have been recaptured by local whitefish fishing boats more than three years after they were tagged by the NAFC Marine Centre UHI.

The first fish was a thornback ray (Raja clavata) caught by the Arcturus (LK 59) on the 8th of November while she was fishing east of Norwick in Unst. The ray had been tagged onboard NAFC’s research vessel Atlantia II in July 2017 and released in the shallow waters near Fetlar, roughly 25 km from where the Arcturus recaptured it. This fits with the fact that thornback rays are known to remain inshore during summer and move offshore into deeper waters during winter. Despite the passage of more than three years the fish had only grown by a single centimetre, from 97 cm when it was tagged in 2017 to 98 cm in when it was recaptured in 2020 indicating that it was close to fully grown when it was tagged..

The second tagged fish was a monkfish (Lophius piscatorius) caught on 13th November by the new Ocean Challenge (LK 253) while fishing north-west of Muckle Flugga. Coincidently, crew member Arthur Johnson who reported this recapture had been the skipper of the Atlantia II when the fish was tagged west of Scalloway in June 2016. Since it was tagged the monkfish had moved more than 100 km to the north, which is consistent with previous NAFC research which found that monkfish move significant distances offshore during the winter. The fish had also almost doubled in size, from 54 cm in 2016 to 103 cm in 2020 which fits with the growth rates of other tagged monkfish,

Between 2013 and 2017 the NAFC Marine Centre tagged a total of 13,745 fish of a variety of species and 1,049 have been recaptured so far. NAFC Fisheries Research Assistant Connor Wood explained that, “With tagging you record the size of individual fish and when and where they are released. So, if they are caught again you can work out how much they’ve grown and how far they’ve travelled since they were tagged. This data can be used to better understand the overall growth and movement patterns of commercially important stocks around Shetland. Every individual fish returned contributes towards a greater understanding of Shetland’s fish populations as a whole.”

Connor thanked the crews of the Arcturus and the Ocean Challenge for reporting these recaptures and all the other fishermen who have returned tagged fish: “It is encouraging that we are still seeing recaptures this long after the tagging project ended but there are likely still many more tagged fish waiting to be caught so we would encourage everyone to continue keeping their eyes open. If you find a tagged fish please keep the whole fish if possible and contact us at nafc.tags@uhi.ac.uk.”

Further Information

Further information about the NAFC Marine Centre’s fish tagging project is available at: https://www.nafc.uhi.ac.uk/research/demersal/fish-tagging/.

For information on what to do if you find a tagged fish please see: https://www.nafc.uhi.ac.uk/research/demersal/fish-tagging/found-a-tagged-fish/.

For further information please contact Connor Wood (connor.wood@uhi.ac.uk, 01595 772218).

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