Researchers tag 1,250 sharks during five-day voyage off Argentina

Researchers at Argentina’s INIDEP institute tagged 1,250 sharks during a five-day voyage aboard the Mar Argentino, according to Revista Puerto. The study aims to improve understanding of movements and growth and strengthen the scientific basis for managing these populations.

Research voyage began on 16 September

INIDEP confirmed that the joint campaign began on 16 September 2026. The programme included conventional tagging of sharks and rays and the collection of biological samples. The work forms part of cooperation under the Argentine–Uruguayan Comisión Técnica Mixta del Frente Marítimo.

Sharks known as gatuzo were also to be marked with oxytetracycline for age and growth studies. The scientific work therefore went beyond tracking migration routes.

Planned satellite tags stayed on board

The announcement also envisaged three satellite tags for sharks. However, programme leader Jorge Colonello told Revista Puerto that no sufficiently large specimens were caught. That part of the project could therefore not be carried out during the voyage. The figure of 1,250 tagged sharks consequently does not mean 1,250 animals fitted with satellite transmitters.

Recaptures provide the crucial information

With conventional tags, the data become particularly valuable through later recaptures. A tag number, together with the capture date, location and, where possible, body length, helps identify individual animals again. This provides clues about movements and growth.

The final report gives the number tagged but no complete breakdown by species. Nor does it demonstrate a recovery of shark populations: the campaign is initially collecting data on which later assessments can build.