Atlantic Bonito

The Atlantic bonito (Sarda sarda) is a fast-swimming member of the tuna and mackerel family Scombridae, found in the Atlantic Ocean, Mediterranean Sea, and Black Sea. It is a schooling predator of coastal and open shelf waters, closely related to true tunas but generally smaller and more slender. Atlantic bonito undertake seasonal migrations following warm currents and prey movements, often appearing in large numbers near coastlines during warmer months. The species is an important mid-trophic-level predator connecting smaller baitfish populations with larger pelagic hunters and is currently considered stable across its wide range.

Atlantic bonito are easily recognized by their distinctive back pattern.

• Body: elongated, rounded, torpedo-shaped, typical of scombrid fishes
• Back: dark steel-blue to greenish, crossed by 5-11 oblique dark stripes running from the back toward the belly
• Belly: silvery-white, unmarked
• Fins: single continuous dorsal fin with a low posterior section, small finlets near the tail
• Teeth: prominent, sharp, visible when the mouth is open
• Size: typically 40-70 cm

The oblique back stripes distinguish Atlantic bonito from mackerels, which have wavy horizontal stripes, and from true tunas, which lack this stripe pattern entirely.

Atlantic bonito occur throughout the temperate and subtropical Atlantic, including the Mediterranean and Black Seas, ranging from Nova Scotia and the Gulf of Maine to Argentina in the west, and from Norway to South Africa in the east. They are epipelagic, generally found from the surface to around 100 m, favoring continental shelf waters near coastlines rather than the deep open ocean. Schools move seasonally, migrating into cooler higher-latitude waters during summer to feed and retreating toward warmer waters in winter.

Atlantic bonito are highly active, schooling predators that hunt cooperatively near the surface, chasing down small fish such as anchovies, sardines, and herring, as well as squid. They are strong, fast swimmers capable of extended pursuit of prey and are known to periodically leap from the water while feeding on schools driven to the surface. Spawning occurs in warmer offshore waters during spring and summer, with females releasing large numbers of small pelagic eggs. As a key intermediate predator, Atlantic bonito link small forage fish populations to larger pelagic hunters like tuna and sharks within coastal food webs.