The North Sea, a dynamic body of water bordering several European countries, often sparks curiosity about the marine life it harbors, particularly sharks. While popular culture sometimes portrays sharks as constant dangers, understanding the specific species present in these cooler waters and their behaviors provides a more accurate picture of any potential risk, promoting a realistic view of sharing the ocean environment with these fascinating creatures.
Shark Species in North Sea Waters
The North Sea is home to a variety of shark species. The porbeagle shark, a year-round resident, resembles a small great white shark but grows to about 12 feet and can weigh over 500 pounds. It is an active predator that feeds primarily on bony fish and cephalopods, capable of maintaining a body temperature warmer than the surrounding water.
The basking shark, the second-largest fish, reaches up to 36 feet and weighing over 10,000 pounds. Despite its immense size, this gentle giant is a filter feeder, consuming plankton and is most commonly observed during the summer plankton blooms. The North Sea also occasionally hosts the Greenland shark, known for its extraordinary longevity, living for up to 500 years. These large sharks, exceeding 20 feet, are sluggish scavengers and predators of fish and marine mammals in deeper, colder habitats.
Other species regularly found include the tope shark, a slender species up to 6 feet long, preying on fish and crustaceans near the seabed. Blue sharks are migratory, visiting UK waters during summer, with sleek, blue bodies and a diet of fish and squid in open ocean environments. The Atlantic thresher shark, known for its elongated tail used to stun prey, also migrates through the North Sea from summer to early autumn. Smaller, bottom-dwelling species like the lesser spotted dogfish and starry smooth-hound are also common.
Evaluating the Danger
Despite the presence of various shark species, the actual risk to humans in North Sea waters is exceptionally low. Shark attacks are rare events, with around 80 unprovoked incidents reported annually, and only a small fraction fatal. The sharks inhabiting the North Sea do not pose a significant threat to swimmers or divers.
The basking shark lacks teeth and predatory behavior to harm humans due to its filter-feeding nature. Historical incidents involving basking sharks are highly unusual and not indicative of predatory behavior. Greenland sharks, while large, are slow-moving, deep-water dwellers, and there are no recorded instances of them attacking humans. Tope sharks are also considered harmless to humans.
Unprovoked shark incidents in British waters, including parts of the North Sea, are infrequent. Records indicate only a handful of such events over the past century and a half. One recent instance in 2022 involved a snorkeler bitten by a blue shark off Cornwall, resulting in non-fatal injuries. Most interactions between humans and sharks are either provoked, such as when a shark is caught or harassed, or are accidental, where the shark may mistake a human for typical prey or react out of curiosity. The cold water temperatures of the North Sea also mean that many of the larger, more aggressive shark species associated with warmer climates are not found there.
Safe Practices in North Sea Waters
Safe practices in North Sea waters contribute to a positive experience for people and marine life. While shark encounters are highly unlikely, general ocean safety measures are beneficial. Avoid swimming alone, particularly during dawn or dusk when some marine animals are more active.
Maintain a respectful distance from all marine wildlife, including sharks; avoid approaching or harassing them. Swimmers and divers should also be mindful of their surroundings and avoid areas with known fishing activity, as fish can attract sharks. Adhering to these guidelines helps ensure safety while enjoying the North Sea’s natural environment.