Sharks are present in Brazilian waters, which encompass a vast stretch of the Atlantic Ocean coastline extending over 7,400 kilometers. This extensive marine territory is home to dozens of shark species. Understanding the distribution and behavior of these populations is important for marine ecology and public safety along the popular coastal areas. The presence of these apex predators is a natural element of the tropical and subtropical ecosystem, though local conditions can sometimes lead to increased human-shark interactions.
Primary Shark Species Found Along the Coast
Brazil’s coastal and oceanic habitats support a diverse range of cartilaginous fish. The Bull Shark (Carcharhinus leucas) is one of the most significant species found close to the shore, often reaching lengths between 2.4 and 3.5 meters. This requiem shark is notable for its ability to tolerate freshwater, allowing it to move into estuaries and far up the Amazon River basin.
The Tiger Shark (Galeocerdo cuvier) is an opportunistic apex predator that can grow to nearly six meters in length. Tiger sharks are recognizable by the dark, vertical stripes that fade as they mature and are frequently found patrolling the shallow, warm, nearshore waters. Their varied diet contributes to their reputation for investigating unfamiliar objects in the water.
The Hammerhead Sharks (Sphyrna spp.) are a less aggressive but ecologically important group, with six species documented along the Brazilian coast. The Scalloped Hammerhead (Sphyrna lewini) is a common example, often forming large schools and utilizing coastal areas as nursery grounds. The largest of the group, the Great Hammerhead (Sphyrna mokarran), can exceed six meters and is occasionally sighted in the tropical parts of the region.
The Nurse Shark (Ginglymostoma cirratum) is a bottom-dwelling species abundant in many rocky and coral reef areas along the coast. Typically reaching about three meters, this shark is docile and often remains motionless on the seafloor during the day. Other smaller species, like the Brazilian Sharpnose Shark (Rhizoprionodon lalandii), which only grows to about 80 centimeters, inhabit the shallow, tropical continental shelf waters.
Geographic Distribution and Preferred Habitats
The distribution of shark populations across Brazil’s coastline varies significantly, driven by regional oceanographic and environmental factors. The Northern Coast, influenced by the Amazon River mouth estuary, features habitats characterized by low salinity and muddy substrates from the Atlantic plume. This area is an important habitat for diverse shark populations, including threatened species like the Daggernose Shark (Isogomphodon oxyrinchus).
The Northeast region, including Pernambuco and Bahia, features warm, tropical waters where the continental shelf narrows close to the shore. These conditions, combined with multiple river mouths and estuaries, create an attractive environment for species such as the Bull Shark and Tiger Shark. Warm currents and deep water channels allow these larger sharks to approach the coast easily for feeding or reproduction.
Moving south, the Southeast coast, such as the Rio de Janeiro Shelf, presents a different profile with extensive sandy bottoms and patches of rocky reefs. This area is influenced by seasonal wind-driven upwelling, which brings nutrient-rich, cooler water to the surface, supporting 25 shark species. Pelagic species, including the filter-feeding Whale Shark, use the southeastern coast as a seasonal feeding ground, typically between February and May.
Further offshore in the deeper pelagic waters, the environment is dominated by migratory species like the Blue Shark (Prionace glauca) and the Shortfin Mako (Isurus oxyrinchus). These species are frequently documented in longline fisheries operating far from the coast in the Atlantic Ocean. Diverse reef systems and oceanic islands, such as Fernando de Noronha, also provide important aggregation sites and protected habitats for numerous reef-associated shark species.
Understanding Shark Activity Hotspots and Mitigation Efforts
The most significant area of heightened shark activity in Brazil is the coast of Pernambuco, especially around Recife. This region experienced a notable increase in shark-human interactions beginning in the early 1990s, with over 60 incidents documented. The primary species identified are the Bull Shark and the Tiger Shark, which are drawn to the coastal environment by environmental and human-made factors.
The construction of the Suape Port complex altered the local marine ecosystem and may have disrupted natural prey availability, contributing to the increased nearshore presence of sharks. The proximity of the coast to estuaries and river mouths, combined with sewage discharge, creates an outflow of nutrient-rich, murky water that attracts Bull Sharks. A deep-water channel also runs close to the shoreline, providing an easy corridor for large sharks to access popular bathing areas.
In response to the elevated risk, Pernambuco implemented the Committee for Monitoring Sharks Incidents (CEMIT) to coordinate research and public safety measures. A component of the response is the Shark Monitoring Program of Recife (SMPR), which employs a selective fishing strategy using drumlines and bottom longlines. This program is designed to catch potentially aggressive sharks, primarily Bull and Tiger Sharks, for tagging and relocation to offshore waters, typically in depths greater than 25 meters.
This “green strategy” of selective removal and relocation, rather than lethal culling or permanent netting, reduced the attack rate by approximately 97% during operational periods. The program is supported by public education campaigns that utilize warning signs posted along high-risk beaches to inform the public about the dangers and bathing prohibitions. Despite these efforts, some beachgoers continue to ignore the warnings, necessitating the ongoing monitoring and relocation program to maintain public safety.