The Mediterranean Sea, a body of water connecting three continents, supports a diverse array of marine life, including approximately 47 different shark species. Its warm, saline waters and varied habitats provide a home for these sharks. They play a role in maintaining the balance of the marine ecosystem, acting as predators that influence prey populations. Despite common perceptions, encounters with sharks in the Mediterranean are rare, and attacks on humans are exceedingly infrequent.
Common Mediterranean Shark Species
The Blue Shark (Prionace glauca) is among the more commonly encountered shark species in the Mediterranean Sea, recognizable by its distinct vibrant blue coloration and slender body. These highly migratory sharks can grow up to 12.5 feet in length and are found in cooler, deeper pelagic waters, though they may occasionally venture closer to shore. Their diet consists primarily of small bony fishes, squids, and other invertebrates. While widespread globally, the Mediterranean population of Blue Sharks shows distinct characteristics.
Another prominent species is the Shortfin Mako Shark (Isurus oxyrinchus), known for its remarkable speed, reaching up to 45 miles per hour. This sleek, streamlined shark possesses a metallic blue coloration dorsally and a white underside, aiding its camouflage in open ocean environments. Shortfin Makos prefer tropical and temperate offshore waters, feeding on bony fishes and cephalopods, and can reach lengths of about 10.5 to 12.5 feet. Both the Blue Shark and Shortfin Mako are pelagic species, meaning they inhabit the open ocean rather than coastal areas.
Various dogfish species are common in the Mediterranean, including the Small-spotted Catshark (Scyliorhinus canicula), also known as the Lesser Spotted Dogfish. This small, bottom-dwelling shark, reaching about 3 feet in length, has a rough, sandpaper-like skin covered in small, dark spots. Small-spotted Catsharks are found over sandy, gravel, or muddy seabeds in coastal waters, at depths up to 330 feet, and hunt for crustaceans, mollusks, and small fish at night. They are oviparous, laying eggs in distinctive “mermaid’s purses” that attach to seaweed or other substrata.
Less Frequently Encountered Species
Great White Sharks (Carcharodon carcharias) are less frequently encountered in the Mediterranean Sea, with sightings being rare. These apex predators, capable of reaching up to 20 feet in length, are known for their powerful build and sharp teeth. Historically, some sightings have occurred in areas like the Sicilian Channel and the Straits of Messina, where they may feed on large bony fish, rays, and other sharks. The Mediterranean population of Great White Sharks is genetically distinct.
The Sixgill Shark, including the Bluntnose Sixgill Shark (Hexanchus griseus), is another species present in the Mediterranean but rarely seen due to its preference for deep-sea habitats. These sharks are found at significant depths during the day, moving closer to the surface in search of prey, which can include other sharks, rays, and large fish, during the night.
Thresher Sharks (Alopias vulpinus), notable for their elongated, whip-like caudal fin which can be as long as the rest of their body, are also found in the Mediterranean. These pelagic sharks inhabit both open ocean and coastal waters, often at depths up to 1,640 feet. Their large eyes are adapted for hunting in low-light conditions. Several catshark species beyond the small-spotted variety, such as the Blackmouth Catshark, also reside in the Mediterranean, often in deeper waters.
Conservation Concerns for Mediterranean Sharks
Shark populations in the Mediterranean Sea face significant conservation challenges, with more than half of the species being threatened with extinction. The Mediterranean is considered one of the most hazardous regions globally for sharks and rays.
Overfishing stands as the primary reason for these declines, encompassing both targeted fishing and incidental bycatch. Many sharks are caught unintentionally in fishing gear aimed at other species, and a substantial portion of these bycatch individuals are discarded, leading to mortality.
Habitat degradation also contributes to the vulnerability of shark populations. Pollution, including plastic contamination, poses a threat, as sharks can ingest plastic items or become entangled in them.
The slow growth rates, late maturity, and low reproductive potential of many shark species make them particularly susceptible to population declines and hinder their recovery. Despite numerous protective measures and legislation across Mediterranean coastal states, enforcement and monitoring vary, and illegal fishing persists. Conservation efforts are ongoing, but the continued demand for shark products and insufficient management measures pose persistent challenges.