Bull Sharks are a surprisingly mobile species that can occupy both freshwater rivers and salty ocean waters. Smithsonian scientists are tagging this shark in an effort to understand their movement patterns and the reasons behind their salinity preferences.
Length: Up to 3.4 m (11.15 ft)
Bull Sharks handle fluctuations in salinity remarkably well-being seen as far as 3700 km up the Amazon River.
Conservation Status: Near Threatened
Although the Bull Shark is commonly seen as an aggressive shark, Smithsonian scientists Matt Ogburn and Chuck Bangley are more interested in studying its movement patterns and how it utilizes its resources. A coastal shark, this species overlaps with areas that are commonly used by humans for recreation and industry, potentially being impacted by coastal development as well as offshore industry such as oil drilling and wind farm production. This species of shark is unique in its ability to handle salinity fluctuations extremely well, sometimes being spotted in inland rivers that connect to the ocean.
These abilities makes the bull shark a prime target for study—how will the effects of human urbanization and development affect a shark that is so flexible in its environment? Can this species learn to survive long-term in water with a lower salinity, or is it bound to the ocean for the resources that it requires there? By tracking individual bull sharks with acoustic telemetry tags and SPOT (Smart Position and Temperature) tags, Smithsonian scientists are hoping to answer these questions and evaluate the movement patterns of this unique shark species. Acoustic telemetry tags are commonly used on fish tracked by the Smithsonian, but the SPOT tags allow for GPS data to be collected, providing rapid transmission of location points for the individual being tracked.
Marine Ecologist
Fisheries Conservation Laboratory Smithsonian Environmental Research Center
Post-Doctoral Research Fellow
Smithsonian Environmental Research Center Fish and Invertebrate Ecology Laboratory
Heupel MR, Simpfendorfer CA (2007) Movement and distribution of young bull sharks Carcharhinus leucas in a variable estuarine environment. Aquat Biol 1:277–289
Harbor Branch Oceanographic Institute at Florida Atlantic University
North Carolina Division of Marine Fisheries
East Carolina University