Tuna Tag Saga!

In this fascinating talk, Jessica shared what happens to Atlantic bluefin tuna after they’re caught, tagged, and released. Using cutting-edge tracking devices, the fish were monitored for up to a year. Right after release, the tuna swam with intense energy but within hours, their activity dropped and stayed low for days.

Eventually, the fish returned to normal behaviour, diving deep during the day and cruising at night. The study revealed that tagging affects tuna longer than previously thought, offering new insights into how these powerful swimmers recover and adapt.

Jessica also recounted a thrilling deep-sea drama in which high-tech tracking devices were used to witness something never seen before: an epic underwater chase between two of the ocean's fastest creatures.

A giant Atlantic bluefin tuna-nearly two meters long and weighing about 80 kg-was tagged with a special biologging device to study its movements. But instead of a peaceful swim, the tuna found itself in a life-or-death sprint from a powerful predator, likely an orca (killer whale). The chase lasted 19 intense minutes, with the tuna darting upward from deep waters at breakneck speed before being caught and brought to the surface.

What makes this story even more incredible is that the orca swallowed the tuna-along with the tracking device. That tag kept recording from inside the whale, giving a rare peek into the daily life of this apex predator, including 77 feeding events and patterns of movement over time.

Jessica emphasised that this remarkable encounter revealed just how much can be learnt from biologging technology and how wild and wonderful life beneath the waves truly is.