Country diary: Ten tonnes of solid muscle, basking sharks are booming here once again

Basking sharks are making a comeback around the Isle of Man, with reports of more than 100 sightings this summer after a sharp decline in earlier years. In Port Erin Bay, the piece recounts close-range tracking work near the island’s waters, including a device being attached to a dorsal fin on a “10-tonne” animal. Researchers had halted basking-shark studies in 2022 when sightings dropped from 885 in 2009 to just one, with hypotheses pointing to lack of food, warmer seas, or underwater electricity cables disrupting migrating sharks via electromagnetic fields. This year’s renewed sightings are concentrated in the island’s southwest, including Bradda Head and entrances to Port Erin Bay, where experts cite a bloom of copepods as the sharks’ main food.