For years, sightings of bluefin tuna in Cornwall were considered a rarity. Now, each autumn, these magnificent ocean giants are becoming a familiar sight once again around the Cornish coast. From Land’s End to St Ives Bay and beyond, they can often be seen chasing shoals of mackerel, sprats and garfish, sending the sea into a frenzy of movement.

When you’re out filming on the cliffs, there’s a certain thrill in spotting the tell-tale signs. Gannets begin to circle high above the water, then plunge headfirst in rapid succession. Moments later the sea explodes as bluefin tuna breach the surface in pursuit of their prey. It’s fast, powerful, and over within seconds, but it’s a spectacle that never fails to take your breath away.

These incredible fish can grow to more than two and a half metres in length and weigh over 500 kilograms. Once considered absent from UK waters for decades, changes in sea temperature and the return of healthy baitfish have brought them back to the southwest, much to the delight of local wildlife watchers and marine researchers.

Filming them takes patience and a bit of luck. Calm conditions help, but the key is to watch the water for any sign of bird activity. When the gannets start diving, there’s a good chance tuna are beneath them. I’ve filmed many of these scenes off Land’s End, where the deep water and tidal currents create ideal hunting grounds.

Seeing these incredible fish back in Cornish waters is a real privilege. It’s a reminder of just how rich and alive the seas around Cornwall are, and how much we still have to learn about the creatures that pass through them.