Sharks often spark public curiosity about their presence in coastal environments. Understanding their natural behaviors and habitats clarifies why some species are regularly observed near coastlines.
Reasons Sharks Are Near Coasts
Coastal waters attract sharks primarily for food and reproduction. These shallower areas teem with smaller fish and marine animals, serving as a primary food source. Some sharks, for example, follow baitfish schools into nearshore zones, creating feeding opportunities.
Many shark species also utilize shallow, protected waters as essential nursery grounds. Female sharks often give birth to their young in these inshore areas, which offer a safer environment for pups to develop, providing protection from larger predators and a rich food supply. Additionally, some shark species prefer shallower depths along coastlines throughout their lives.
Common Nearshore Shark Species
Several shark species are frequently found inhabiting coastal and nearshore environments. Blacktip sharks, for instance, are common along beaches, in bays, and estuaries, often migrating along coastlines. They are known for their active feeding behavior, sometimes leaping and spinning out of the water while pursuing prey. Spinner sharks, closely related to blacktips, also prefer shallow coastal waters and are named for their distinctive spinning leaps during feeding. Both species typically range from 5 to 9 feet in length.
Nurse sharks are another species commonly encountered in warm, shallow coastal waters, often resting on the seafloor during the day. These bottom-dwelling sharks can reach up to 14 feet long and are known for their strong suction feeding ability, preying on crustaceans and small fish found in crevices. Juvenile lemon sharks also frequent shallow tidal creeks and mangrove systems, which serve as important nursery habitats for their early growth. Bull sharks are notable for their ability to tolerate varying salinity levels, allowing them to venture into brackish estuaries and even freshwater rivers, bringing them into frequent contact with human activity in shallow areas.
How Close Sharks Get
Sharks can indeed come close to the shoreline, often swimming in waters just a few feet deep. Studies have shown that some species, like juvenile white sharks, may spend considerable time in waters less than 15 feet deep. This proximity often occurs when sharks are foraging for food, as schools of baitfish can congregate very near beaches. Their presence in shallow water is natural, particularly for species preferring these habitats or using them as nurseries.
Sharks do not intentionally “beach” themselves or come ashore unless distressed, disoriented, or actively pursuing prey in extremely shallow water. Sightings near the surf zone are typically due to prey pursuit or natural migratory patterns. Tides and currents can also influence how close sharks move to the shore, as water movement affects prey distribution and provides pathways for travel. Though sharks can be close, most human encounters are incidental, occurring when both are present in the same shallow areas.
Minimizing Encounters
Individuals can take several precautions to reduce the likelihood of a shark encounter in coastal waters. Avoiding swimming at dawn or dusk, or at night, is advisable, as these are peak feeding times for many shark species. Murky or turbid waters can also increase risk because they reduce visibility for both humans and sharks, making it harder for sharks to identify prey accurately. It is also prudent to avoid swimming near areas where there is active fishing, or where schools of baitfish are visible, as these situations can attract sharks.
Refraining from wearing shiny jewelry while in the water can help, as reflections might resemble fish scales and attract a shark’s attention. Swimming in groups can also provide a measure of safety, as sharks are less likely to approach larger aggregations. Remaining calm and avoiding erratic movements if a shark is sighted can also be beneficial.