Tagged sand tiger shark recaptured after 26 years in South Africa

News Release

ORI TAG (Oceanographic Research Institute)

07. April 2020

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On the 13th March 2020 a day in history was made for the ORI – Cooperative Fish Tagging Project. Our 1 014th raggedtooth shark (Carcharias taurus) was recaptured after spending an incredible 9 591 days (26.2 years), in total, at liberty with the same tag inserted. This is a new record for the longest time at liberty for a tagged fish, as well as the longest time that a single tag has remained in an animal in the ORI–CFTP. Our previous record was also from a raggie which was at liberty for 8 256 days (22.6 years).

This female raggie was originally tagged by Geremy Cliff, from the KwaZulu-Natal Sharks Board, on the 9th December 1993 at Leven Point, 22 km north of Cape Vidal, KZN, measuring approximately 1 800 mm PCL. The tag was inserted underwater using a modified speargun. Geremy had this to say about the recapture: “This is excellent news; it is great to know that all the fun we had tagging raggies at Leven has also had some important scientific value”. After being at liberty for 1 397 days (3.8 years) she was first recaptured by Dr Vincent Taylor at the Strand, Western Cape, on the 6th October 1997 (unfortunately no length was recorded), having moved 1 897 km south. After being released again, she was recaptured a second time some 8 194 days (22.4 years) later (with the same, original tag) on the 13th March 2020 by Shawn Mey at Frankman’s Hoek, Western Cape, measuring 2 010 mm PCL, 435 km north of the first recapture locality. She only grew 210 mm in just under 27 years showing the extremely slow growth rate of these animals (see Govender et al. 1991) and was caught at various localities along the coast showing the typical migration pattern of raggies (see Klein et al. 2019). Shawn re-tagged her with a new tag, and she was released again to continue her journey and hopefully be recaptured again in the future.

We would like to thank the manufacturers of our tags, Hallprint Pty. Ltd. in Australia, for their outstanding tag quality and the support they have given us over the last 35 years of the ORI-CFTP. A recapture like this would not have been possible without such high-quality tags. When we told David Hall, from Hallprint, about the recapture he had the following words to say: “Hallprint founder, Michael Hall always said these SSD tags were “indestructible”! As a fisheries scientist who motivated my father to produce these tags in the early 1980s this is a proud moment for myself personally – as it is for Darren and the staff that operate the company now. If nothing else this recapture shows the value in long term programs like yours supported by quality products like ours!”. Hallprint’s general manager, Darren Evans, also commented saying: “I think this may actually be a world record for any Hallprint external fish tag! Up to now the longest reported time at liberty for any Hallprint tag was on a southern bluefin tuna at 9 525 days, with the next closest being an Australian bass at 9 507 days (both of those animals still carry the original tag and are at still at liberty). However, your recapture report is some two months longer. This is a fantastic achievement for your program and everyone involved and is certainly something to celebrate”.

We would also like to thank all our taggers and the members of the public for their ongoing support and reporting these incredible recaptures to us! Keep up the good work!

Source: ORI TAG (facebook)

1 Comment

  1. This is great news. We have ages validated for this species using bomb radiocarbon.  These tag-recapture findings provide additional support for the idea that this species has a longevity that very likely exceeds 40 years. If you are interested in the work you can either contact me or visit the link for the published paper here: https://www.publish.csiro.au/mf/MF13214
    Cheers, Allen

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