In South Florida, there is no shortage of sharks. The warm salt waters and abundance of reefs make it the perfect habitat for many species to thrive. Not only do sharks need the optimal conditions South Florida’s ecosystems offer, but the ecosystems need the sharks. Sharks play an essential role in maintaining ecological balance and biodiversity in coral reefs. Without sharks, overgrazing would take over reefs and the fragile balance of marine ecosystems would be shattered. Here are some species you may encounter in South Florida waters:

Nurse Shark (Ginglymostoma cirratum)

Most commonly found in the Atlantic reefs of warm coastal areas, nurse sharks are considered a virtually harmless, docile species. They feed on mostly shrimp, squid, and sometimes crush corals using their jaws. While nurse sharks are considered generally passive, they will bite as a self-defense tactic if startled. It is best to leave the species be, but if not provoked, nurse sharks are safe to be in the water with. Contrary to its calm demeanor, nurse sharks can be as large as 14 feet long. They are identifiable by their gray-brown color and small tail fin.

The shark is a nocturnal bottom dweller, so during the day, it resides in deeper waters, coming closer to the shores at nighttime. Unlike other sharks, nurse sharks do not have to keep moving to breathe so, you may find a pile of up to 40 nurse sharks resting.

Bull Shark (Carcharhinus leucas)

Bull Sharks are considered an apex predator of Atlantic marine life. Not only are they one of the most dangerous shark species- they are responsible for the 3rd highest number of human attacks- but they are also euryhaline. This means that Bull sharks can live in both saltwater and freshwater. Their ability to survive in freshwater allows the shark to come into very close proximity with humans through coastal river systems that lead inland. The prey of bull sharks varies from sea turtles to Crustaceans (lobster, crab, and shrimp). The predator is considered a medium-sized species, with males averaging a length maximum of 11.8 feet. Female bull sharks are slightly larger at 13 feet long, weighing in at almost 700 pounds.

Bull Sharks are notoriously aggressive by nature and attack via a bump-and-bite method. The shark will first tap its prey, then back off and re-attack, going in for the bite. While Bull Sharks can be violent, it is important to remember that there are on average only 120 bull shark attacks recorded in history, 100 of those being nonfatal, so the odds of being seriously harmed are very low.

Tiger Shark (Galeocerdo cuvier)

This unique shark is most identifiable by its ‘tiger’ stripes on its back. These stripes fade with age, but can still be seen visibly in many cases. Measuring up to 16 feet and weighing sometimes over 1,400 pounds, Tiger Sharks are known for their flexible diet. They eat virtually anything available- from smaller sharks and birds to sometimes garbage. These feeding habits offer yet another reason to keep the oceans clean, as consuming trash is both harmful to the shark and disrupts the feeding behavior needed to maintain a balanced ecosystem. Because of their broad diet, tiger sharks may mistake a human for food, making them 2nd most likely to bite humans worldwide.

Tiger sharks prefer tropical waters around the world and frequently dwell near the shore in shallow waters. They can be found in open waters, the mouths of rivers, and bays. Known to be a curious hunter, the species will often approach boats, surfers, and divers adding to their hazard level. The IUCN (International Union for Conservation of Nature) has classified Tiger Sharks as a threatened species because of overfishing and low reproduction rates among the species.

Hammerhead Sharks (Various Species)

There are 9 total species of Hammerhead sharks, and several of them can be frequently found in South Florida. The majority of the species prefer warm waters but they live in a variety of environments; both in deep waters as well as coastal areas and continental shelves. All Hammerheads have a cephalofoil head structure, meaning it has a widened and flattened front profile. Here are three of the most common Florida Hammerheads:

Great Hammerhead sharks (Sphyrna mokarran)

The largest of the hammerheads, the Great Hammerhead can be up to 20 feet long. Its tall, pointed dorsal fin makes the species easily spottable in the water. While most Hammerheads are considered relatively harmless, the Great Hammerhead is potentially a threat to humans because of its size. They migrate based on water temperatures, frequently seeking cooler seas in the summer months. Considered the Apex predator of its ecosystems, Great Hammerheads regulate the population sizes of stingrays and smaller sharks through their eating patterns.

Scalloped Hammerhead sharks (Sphyrna lewini)

Scalloped Hammerheads are smaller than great hammerheads averaging 11 feet long. The species can be found globally in parts of Africa, Asia, and Australia. This Hammerhead’s most distinctive feature is the multiple divots in its head that create its scalloped appearance. Other Hammerheads have one divot at the center of the head, giving the Scalloped hammerhead a unique look. The species is protected under the Endangered Species Act due to commercial fishing practices.

Bonnethead Sharks (Sphyrna tiburo)

Not only does its small size (2.5-4 feet long) distinguish it from other Hammerheads, but Bonnethead Sharks also have a more rounded cephalopod than the other 8 species variants. Instead of being described as a ‘hammer’ the Bonnethead resembles more of a shovel and maintains a very different diet due to its size. It consumes small fish and mollusks near the shores of South Florida. They migrate in small packs of 5-15 sharks throughout the seasons, seeking waters at about 70º Fahrenheit. Known as a timid shark, Bonnetheads do not approach humans and are very passive. There is only 1 recorded bonnethead attack in history.

It may seem like a shark attacking you is imminent because of how many species roam the South Florida waters, but this is simply not true. PETA (People for the Ethical Treatment of Animals) states that 1 human dies from a shark attack every two years, making your odds of experiencing a fatal attack 1 in 3.7 million. What you should fear is the number of sharks being killed every year. 121 shark species are endangered, 90 are critically endangered, and over 180 species are classified as vulnerable. If these essential pieces of marine life are not protected, ecosystems will fail and be destroyed. Do your part and help protect these vulnerable Florida residents.

Written by: Lauren Costigan

References

https://myfwc.com/research/saltwater/sharks-rays/shark-species/bull/#:~:text=Common%20apex%20predator%20that%20inhabits,inland%20via%20coastal%20river%20systems.

https://chnep.wateratlas.usf.edu/upload/documents/SharkPharmaceuticalSummary_Mote.pdf

https://www.britannica.com/animal/bull-shark

https://www.nationalgeographic.com/animals/fish/facts/nurse-shark

https://scaquarium.org/our-animals/nurse-shark/

https://www.barrierreef.org/news/news/sharks-to-be-revered-not-feared#:~:text=Sharks%20are%20often%20portrayed%20as,balance%20of%20these%20fragile%20ecosystems.

https://myfwc.com/wildlifehabitats/profiles/saltwater/sharks/tiger-shark/

https://www.nature.org/en-us/get-involved/how-to-help/animals-we-protect/tiger-shark/#:~:text=Since%20they%20have%20a%20low,the%20species%20as%20near%20threatened.

https://myfwc.com/research/saltwater/sharks-rays/shark-species/great-hammerhead/

https://www.nationalgeographic.com/animals/fish/facts/hammerhead-sharks