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Acoustic tagging of diamond rays

On Monday the 6th February 2023 three scientists from the ORI Linefish team went up to Port Durnford in northern KwaZulu-Natal (KZN), to join anglers fishing in the South Africa Shore Angling Association (SAASA) and Development Division, B-Nationals fishing competition. The Linefish team’s goal was to tag diamond rays caught by the competition anglers with acoustic telemetry tags to contribute towards an ongoing study on the movement of this species.

This is being done in collaboration with the Acoustic Tracking Array Platform (ATAP), which is a platform hosted by the South African Institute for Aquatic Biodiversity (SAIAB).

It was a very successful day with four diamond rays being tagged, bringing the total number of tagged individuals to 14 in KZN and 41 tagged in total along the South African coast (27 have been tagged by SAIAB staff between Algoa Bay and Struisbaai), said ORI Assistant Scientist, Gareth Jordaan.  

A recent study undertaken using conventional dart tagging data from the ORI Cooperative Fish Tagging Project (ORI-CFTP) has indicated that this species is capable of making large scale movements (more than 1700 km) from the cooler waters in the Western Cape to the warmer waters of KZN. However, the driving factors behind these movements are still largely unknown. Therefore, we are hoping that the new more defined movement data received from the acoustic telemetry study of these animals will give us more insights and information about these longshore movements.