Sharks play an essential rol in the health of our oceans

Information, Research

Bull sharks – going up and down the river

Bull sharks can thrive in both salt water and freshwater and can travel far up rivers. As bull sharks like to hunt in murky waters, they are probably responsible for the majority of near-shore shark attacks, including many incidents contributed to other species. This species uses the low visibility as camouflage, and is attracted to busy places like river mouths and marinas, where fish (and people) gather. They are often found near high-population areas like tropical shorelines, and unfortunately also near popular surf beaches, like the beach in Ile de Réunion, where there have been several fatalities this year. Bull sharks seem to bite because of ‘mistaken identity’ or out of curiosity in bad visibility to examine possible prey. Dutch Shark Society Photographer Peter Verhoog has often dived and snorkelled with bull sharks without any problem.

Bull Shark in the Bahamas, picture by Peter Verhoog

Bull sharks can live up to 16 years and have a maximum length of 3,4 meter. They are medium-size sharks, with thick, stout bodies with a grey back and lighter belly, and long pectoral fins with darker tips, particularly on young individuals sharks. They feed on fish, but also on dolphins and other sharks.

These sharks are not (yet) threatened or endangered, but are fished widely for their meat, skin and oils, and their numbers are likely shrinking. One study has found that their average lengths have declined significantly over the past few decades.

Bull sharks have been found thousands of miles up rivers like the Amazon River, the Mississipi and Zambezi.

Bull sharks are not true freshwater sharks, despite their ability to survive in freshwater habitats (unlike the river sharks of the genus Glyphis, see one of our previous posts: http://www.dutchsharksociety.org/did-you-know-sharks-that-live-in-fresh-waters-only/ ).

One of the groups that studies the bull shark in its freshwater environment is the Freshwater Fish Group & Fish Health Unit of the Australian Murdoch University (www.freshwaterfishgroup.com). They tag bull sharks in Fitzroy river.

In the video below, you can watch a bull shark in fresh water that was tagged and filmed by the researchers.

Comments are closed.

Contact info

You can contact us at +31 (0) 6 12195593 Or per email at: georgina@dutchsharksociety.org

Partner organisations

De Dutch Shark Society is proud to be a partner of several organisations. Check out our Mission page!
Show Buttons
Share On Facebook
Share On Twitter
Share On Pinterest
Contact us
Hide Buttons