First described in 1839, the Bull Shark is perfectly adapted for life at sea as well as in freshwater! Scroll down to learn more about this fascinating (and one of our favorite) species.
FAMILY: Carcharhinidae (requiem sharks)
SCIENTIFIC NAME: Carcharhinus leucas
COMMON NAME: Bull Shark
TYPE: Fish
The name comes from their short, blunt snouts, pugnacious/aggressive disposition and tendency to head-butt their prey before attacking.
IUCN Red List Status: Vulnerable (assessed 2020)
SIZE:
Average between 7-11ft and weigh between 200-700lbs.
AVERAGE LIFE SPAN:
Average lifespan is 16 years but scientists estimate they could live around 25 years with an estimated maturation age of 15-18 years.
DISTRIBUTION:
Preferring the shallow coastal waters (less than 100ft deep), Bull sharks are found in tropical to subtropical coastal waters, worldwide.
COOL FACT:
Thanks to special glands and kidney functions (aka: urination) these sharks can retain salt whilst in freshwater!
Bull sharks also occur in a number of river systems and freshwater lakes; they've been reported up the Amazon and Mississippi Rivers and have been seen leaping up river rapids to reach inland lakes!
Bull sharks have been documented in 125 freshwater rivers and lakes across all continents in its range.
DIET:
Carnivores and generally solo agile hunters, bull sharks will eat almost anything, including fish, squid, dolphins, turtles, birds, rays and other sharks.
As Bull sharks have small eyes relative to other carcharhinid sharks, it suggests that vision may not be as important for this species which often occur in murky waters.
According to the International Shark Attack File (ISAF), bull sharks are historically responsible for at least 100 unprovoked attacks on humans around the world, 27 of which have been fatal.
..."considered the likely culprit for the infamous series of five attacks that occurred
in New Jersey in 1916 that resulted in four fatalities over a 12 day period.
Three of these attacks occurred in Matawan Creek, a shallow tidal river,
only 40 feet (12 m) across, 1.5 miles (2.4 km) from bay waters, and over
15 miles (24 km) from the open ocean; not a location where any other
large shark species would likely occur. A 7.5 foot (2.25 m) white shark
was captured two days after the last attack, 4 miles (6.4 km) from the
mouth of Matawan Creek, and allegedly contained human remains
in its stomach. A 9 foot (2.7 m) bull shark was also captured a day
later only 10 miles (16 km) from Matawan. This has been a topic of
controversy for many years, and there is evidence that points to the
involvement of both the bull shark and the white shark.
It has not yet been conclusively resolved."
DID YOU KNOW:
Bull sharks were blamed for a series of attacks in 1916, which served as inspiration for Peter Benchley’s book 'Jaws'. In 1975, Steven Spielberg would turn that into a movie that would negatively impact sharks for generations to come.
Subscribe to BBC Earth's YouTube Channel
CONSERVATION:
Due to the fact these sharks live so closely to human populations, it is vulnerable to human impact. With a bad reputation for attacking humans and considered by many to be the most dangerous shark in the world due to it's unique ability to navigate into rivers and inland lakes- the truth is that humans pose a much larger threat to sharks than they do to us.Â
Overall, it is suspected that the Bull Shark has undergone a population reduction of 30–49% over the past three generation lengths (55–80 years).
Bull Sharks are used for their meat which may be consumed fresh locally or fins are dried for export. Shark skin and liver oil are also used commercially for leather and healthcare supplements. Bull Sharks are also targeted by trophy fisherman, commonly pulled up as bycatch and or caught in longline fishing gear.
If those threats weren't enough, the bull is a species that is also exploited by large aquariums as it adapts well to captivity life while providing an example of a large "aggressive" shark. At present, however, there is no evidence that collecting for aquaria has any impact on wild populations of bull shark.
Right now, these sharks are targeted in culling operations advertised to promote the safety of beachgoers and other tourists while in the water.
The fact is: Cull mentality is not proven to be an effective method/practice in protecting swimmers from attacks and generally does more harm than good to tourists as well as unintended animal species (whales, seals, sea birds, etc.)Â
TAKE ACTION: End the CULL
Follow + Watch: Envoy: Shark Cull
Check out more in-depth information at these source links!