SardineWhere and when to see them

When diving with large sardine aggregations, maintaining excellent, neutral buoyancy and situational awareness is vital. Avoid swimming aggressively straight into the centre of a bait ball, as this fractures the school and disperses the fish; instead, hold your position along the perimeter and allow the shoal to swirl naturally around you. During high-octane predation events, such as the South African Sardine Run, remain mindful of larger predators—including sharks, seals, and plummeting seabirds—which may breach the shoal at tremendous speed with limited visibility. Keep your profile compact and stay close to your dive buddy or guide. For underwater photography, a wide-angle or fisheye lens is essential to capture the immense scale of the shoal. Rely on natural ambient light, fast shutter speeds (1/250s or higher), and moderate ISO to freeze the dynamic motion without backscatter from the swirling scales.

To witness the world’s most dramatic sardine congregations, timing is everything. The legendary Sardine Run along the Wild Coast of South Africa peaks from late May through July, when cold northward currents drive immense shoals past Port Saint Johns and East London. In Moalboal, situated on the island of Cebu in the Philippines, massive, resident bait balls are present year-round just metres from the shore, though the calmest sea conditions and best underwater visibility occur between November and May. In Baja California Sur, Mexico, particularly around Magdalena Bay, autumn aggregations between October and December offer spectacular encounters with striped marlin, sea lions, and pelagic sharks hunting dense sardine aggregations in pristine Pacific waters.

Sardines are epipelagic, schooling fish found predominantly in temperate, subtropical, and tropical coastal waters across the world's oceans. They inhabit the water column from the sunlit surface down to depths of roughly 200 metres, though they are most frequently encountered in the upper 50 metres. Sardines thrive within nutrient-dense coastal upwelling systems, boundary currents, and productive continental shelf waters. Key geographic ranges include the eastern Pacific from Alaska to Baja California and along the Humboldt Current off Peru and Chile, the eastern Atlantic from the North Sea down through the Mediterranean to West Africa, the Agulhas Current system off eastern South Africa, and the vibrant coastal drop-offs around the Indo-Pacific archipelago, such as the Philippines.

Sardines are opportunistic filter feeders and particulate grazers that primarily consume microscopic planktonic organisms. Their diet is dominated by phytoplankton, such as diatoms and dinoflagellates, alongside nutrient-rich zooplankton including copepods, crustacean larvae, fish eggs, and juvenile krill. Feeding occurs through two distinct methods depending on the density and size of prey in the water column. When encountering dense patches of micro-algae or small plankters, sardines swim steadily with their mouths wide agape, using finely spaced, specialised gill rakers to strain food particles continuously from the sea. When larger prey items such as mature copepods or euphausiids are detected, the fish switch to selective particulate feeding, snapping up individual targets with rapid precision. Feeding activity is most intense during daylight and twilight hours within nutrient-rich upwelling zones.