70 years of helping people to care for our ocean

ORI Tag’s contribution towards shark research

By: Gareth Jordaan

Today we decided to share some interesting information on the ORI Cooperative Fish Tagging Project’s “Fin-tastic” contribution towards shark research.

Since the start of the ORI – Cooperative Fish Tagging Project (ORI-CFTP) in 1984, the project has recorded over 83 700 tagged sharks from 14 different families and 58 different species, with more than 5 900 (7%) of these being recaptured. This has produced a gold mine of information, much of it found nowhere else in the world given the variety and number of endemic species that we have around the southern African coastline!

We have been able to use some of this information to study and analyse various movement patterns, growth rates, stock status and population dynamics of many of these species.

For example, we have seen how far raggedtooth, dusky, copper/bronze whaler, tiger, hammerhead sharks, as well as giant sandsharks (to name a few) migrate at certain times of the year for various reasons. We have also seen how some species are extremely resident like the flapnosed houndshark, spotted gullyshark, striped and leopard catshark as these have been recaptured in exactly the same place many years later, sometimes on multiple occasions.

We have also been able to use the recapture data to analyse the growth rates of certain shark species such as the broadnosed sevengill shark (which grows very slowly), as well as contribute important data to stock assessments that have been used to evaluate species on the IUCN Red List.

Some of our incredible shark recaptures from the ORI-CFTP include a tiger shark that moved 4 067 km after being tagged in Umtentweni, KwaZulu-Natal, and recaptured in Madagascar; a raggedtooth shark that was recaptured having the same tag in it after more than 26 years; as well as a leopard catshark that has been recaptured no less than seven times in the same location!

Ultimately, the ORI-CFTP has helped contribute towards improving the conservation and management of many of our shark species, especially those that have a vulnerable life history strategy (e.g. slow growth-rate, long life-span, long gestation period, produce few pups, etc.).

We would like to thank our tagging members for their incredible efforts over the years and we also thank the angling public who have reported important tag recaptures back to us. The ORI-CFTP wouldn’t be where it is today without your ongoing support!

If you would like to know more about the ORI Cooperative Fish Tagging Project please send an email to oritag@ori.org.za.