Sandbar sharks are medium-sized, common coastal sharks known for their distinctive tall dorsal fins and brownish-gray coloration. They average around 6 feet in length and weigh between 110 and 150 pounds, though some can reach up to 8 feet and 200 pounds. This article explores their diverse global habitats and seasonal movements.
Global Geographic Span
Sandbar sharks inhabit temperate and tropical waters across the world’s major ocean basins. They are prevalent in the Western Atlantic, ranging from Cape Cod, Massachusetts, down to Argentina, including the Gulf of Mexico and parts of the Caribbean. In the Eastern Atlantic, their range extends from Portugal to equatorial Africa, encompassing the Mediterranean Sea.
Beyond the Atlantic, sandbar sharks are found throughout the Indo-Pacific region. This includes areas from the Persian Gulf, the Red Sea, and South and East Africa to the Hawaiian Islands. They are also present in the Eastern Pacific, specifically around the Revillagigedo and Galapagos islands.
Coastal and Nearshore Preferences
Sandbar sharks inhabit coastal and nearshore waters, favoring areas with sandy or muddy bottoms. They are frequently found in bays, harbors, estuaries, and at the mouths of rivers, avoiding coral reefs or rougher substrates. These environments offer both camouflage and access to a variety of prey items.
Sandbar sharks are primarily bottom-dwelling, occupying depths ranging from 60 to 200 feet (18 to 61 meters). They can occasionally venture into deeper offshore waters, reaching depths of up to 810 to 900 feet (247 to 274 meters). Their preference for these shallower, often turbid, coastal areas is linked to abundant food and warmer water.
Seasonal Movements and Nursery Grounds
Sandbar sharks undertake seasonal migrations, driven by changes in water temperature and reproductive cycles. In the Western North Atlantic, for instance, adults move northward to areas like Cape Cod during warmer summer months. As coastal waters cool with the onset of fall and winter, they migrate southward to warmer regions, from the Carolinas to Florida and into the Gulf of Mexico.
These migrations often involve segregation by sex, with males sometimes forming large schools and traveling in deeper waters, while females more commonly migrate alone. These movements lead to specific areas known as nursery grounds, which are shallow, protected coastal habitats. These nurseries are important for gestation and the birth of young, offering a safer environment with abundant food and reduced predation risk for pups.
Prominent nursery areas along the U.S. East Coast include bays and estuaries from Delaware to North Carolina, such as the Chesapeake Bay and Delaware Bay. Pups are born in these shallow waters between June and August in the Western Atlantic. Juvenile sharks remain in or near these nursery areas for about 9 to 10 months, benefiting from warmer temperatures and ample food, before moving into deeper waters as temperatures drop.