Common Dolphinfish

Photo: Rafael de la Parra · CC BY-NC

Dolphinfish — also known as mahi-mahi — appear in the blue water beyond Flagstaff Wall's upper edge during October through March, their neon green-blue-yellow colouration blazing in the clear South Atlantic water as they hunt flying fish and surface-swimming squid along the wall edge. Males develop the characteristic bony crest on the forehead that is visible at range, making them identifiable even in poor conditions. Their presence at the wall edge indicates the open ocean productivity that the island's seamount geography generates — and which ultimately underpins all of Saint Helena's marine megafauna encounters.