Bull Sharks Flooded Out of Golf Course Home After 17 Years

In 1996 severe flooding around Brisbane, Australia swept six young bull sharks into a landlocked (mostly) freshwater lake on a golf course. The floodwaters receded but the sharks were trapped in the 51-acre lake off the 14th hole. Incredibly, the sharks lived there for 17 years.

The sharks survived by feasting on fish in the well-stocked lake, as well as on the occasional meaty treats tossed in by staff of the Carbrook Golf Club. The really neat trick is that the predators adapted to the low-salinity water, which would have killed off most other shark species.

Apparently the bull shark (Carcharhinus leucas) has very special kidneys and rectal glands that can recycle and retain the salt in their bodies. Because this group lasted 17 years, scientists now think their special adaptive ability can go on indefinitely.

One of the sharks was (illegally) fished out; the others lived on until subsequent flooding swept the group away. They hung around long enough for scientists to observe and study the group; their research appears in the journal Marine and Fisheries Sciences.

The bull shark – which can grow to 13 feet in length and weigh more than 500 pounds – is sometimes seen prowling in freshwater and brackish rivers, estuaries, and lagoons. This puts them in closer proximity to human habitats than other species, and probably accounts for their high body count with unprovoked attacks on people: they rank third in the world, behind great white and tiger sharks.

The world’s most dangerous water hazard did not faze the humans at the Carbrook Golf Club, who were delighted to have the killer interlopers in their lake. Eventually the club even adopted a shark silhouette for the company logo.

Photo credit: Scott Wagstaff / New York Times