Yellowfin Tuna

Photo: Almcglashan · CC BY-SA

Yellowfin tuna are the primary hunters that drive the schooling behaviour of smaller fish at Jokombo, launching attacks from depth at speeds exceeding 70 kilometres per hour. Their presence in the water column above a seamount is often announced before they are visible by the sudden compression and direction change of the bait ball — divers learn to watch for this behaviour as a predictor of a tuna attack. Encounters are most common from late spring through autumn when warmer surface temperatures support the tuna's preferred thermal range.