01/11/2023
🎣𝑬𝑿𝑪𝑰𝑻𝑰𝑵𝑮 𝑻𝑨𝑮 𝑹𝑬𝑪𝑨𝑷𝑻𝑼𝑹𝑬🎣
On the 20th October 2023 the ORI Cooperative Fish Tagging Project (ORI-CFTP) had its 446th copper/bronze whaler shark tag recapture.
This bronzie was originally tagged on the 11th December 2012 by Ebrahim Dien at Tweede Baai, Western Cape (WC), measuring 204 cm Pre-caudal Length (PCL). It was recaptured 3 965 days (10.9 years) later by Pieter du Toit at Uilenkraalsmond, WC, measuring 215 cm PCL. During its 10.9 years at liberty, this bronzie moved about 153 km and grew about 11 cm.
Bronzies are a widespread species found in warm-temperate oceans including the south-western and eastern Atlantic, Mediterranean, south-eastern and south-western Indian Ocean and the south-western and south-eastern Pacific. In southern African waters they are found from Durban to Angola, but are rare on the west coast between Cape Point and Walvis Bay in Namibia. They occur over the continental shelf from the surf-zone to at least 100 m depth either close to the surface or near the bottom. Juveniles are found in coastal waters in the Eastern and WC. They reach maturity at 180 – 190 cm PCL and an age of 20 – 22 years. In South African waters they can reach a maximum size of 312 cm Total Length, a weight of up to 203 kg, and have been aged up to 30 years. They are an extremely slow growing species with juveniles growing about 7.6 cm per year and adults 2.1 cm per year in South African waters (Rogers et al. 2022).
A recent study by Rogers et al. (2022) showed that bronzies are a migratory species that show extensive movements throughout their southern African distribution. During the winter months they pe*****te into KwaZulu-Natal (KZN) waters during the annual sardine run. The current status of bronzies in South African waters in unknown, but they were recently (2020) evaluated as Vulnerable on the IUCN Red List. This is mainly due to their capture in a variety of different fisheries. They are targeted by competitive shore anglers, but most are released alive. Juveniles are sometimes caught and kept by commercial ski-boat fisherman depending on market availability. Adult individuals are captured in the shark nets in KZN, particularly during the winter months. They are occasionally caught by pelagic tuna and swordfish directed longline vessels, as well as by demersal shark longline, midwater trawl, inshore and offshore trawl and even occasionally by pilchard purse seine fishing vessels as bycatch. They are also one of several species taken by beach seine nets in the WC. Due to their vulnerability to capture and their life history traits, bronze whaler sharks are extremely vulnerable to overexploitation in southern African waters and require careful, science-based management plans to ensure their effective conservation.
For more interesting information on our linefish species, be sure to download the ORI Fish App Marine Fish Guide for Southern Africa from Google Play (Android) or the App Store (iPhone). Be sure to also check out our websites at www.oritag.org.za and www.saambr.org.za/for-fishermen/ as well as follow our ORI-CFTP Instagram page . We would like to thank all our taggers and the members of the angling public for their ongoing support and reporting these exciting recaptures to us. Please keep up the good work!
SAAMBR
