Sharks in the Mississippi

On February 12, 2006, divers working with Wisconsin DNR Fisheries personnel, caught this five-foot female Bull Shark under the ice on Lake Pepin, part of the Mississippi River. The nearly dormant shark was tagged with a radio tracking device and released. Photo courtesy of the Wisconsin Bureau of Fisheries Management and Habitat Protection.

Coming home from dinner in Memphis on Saturday night, I mentioned to friends Charlie and Deb that there are sharks in the Mississippi River. I said it as we were crossing the river on the perpetually-under-improvement “new” bridge.

This is apparently news to a lot of people. I learned about it just a few months ago and have since done a little Internet research.

Bull Sharks have been found in the river as far upstream as Wisconsin and Minnesota.

The most extreme example I’ve found so far involves the 5-foot female Bull Shark in the photo above. Ice-diving biologists captured the nearly comotose shark in Lake Pepin, a widening of the Mississippi River. They were responding to reports from several startled salvage divers of a sleeping, “shark-like fish” in the open cab of a pickup truck that had gone through the ice a few weeks earlier. The Wisconsin divers found the truck in about 18 feet' of water with the shark still inside, apparently sheltering from the swift current. The cold water had slowed its respiration and metabolism so much that it was barely alive. After an examination, the fish was tagged with a radio location device and released back into the river (Wisconsin regulations do not allow the keeping or transport of live, non-game fish). I can’t find any reports of subsequent tracking.

Worried about the negative effect on local recreation a man-eating shark might possibly cause, Minnesota officials ordered an immediate sweep of Minnehaha Creek. On Saturday, March 26, conservation officers began their search below the falls using ultrasonic stun devices to drive any fish downstream and into gill nets strung across the mouth of the creek. Despite catcalls and hoots from park patrons, the team worked downstream throughout the day and into the night. It was difficult work with shallow water and an unusual number of recently downed trees blocking the creek.

A little after midnight, two juvenile sharks were captured along with dozens of rough fish and several spawning Northern Pike. Both sharks were malnourished and docile, but in overall better health than the larger Lake Pepin specimen. The two fish are now in a special hospital tank at the Minnesota Zoo in Apple Valley, undergoing observation and a slow acclimatization back to salt water. The staff there have named them Lenny and Frankie, after two of the characters from the 2004 animated feature, Shark Tale.

There are also reports of Bull Sharks being caught in the river near Alton, Ill.

Wikipedia notes:

Bull Sharks are common worldwide in warm, shallow waters along coasts and in rivers. The bull shark is well known for its unpredictable, often aggressive behavior. Since Bull Sharks often dwell in shallow waters, they may be more dangerous to humans than any other species of shark and, along with tiger sharks and great white sharks, are among the three shark species most likely to attack humans.

Unlike most sharks, bull sharks tolerate fresh water and can travel far up rivers. As a result, they are probably responsible for the majority of near-shore shark attacks, including many attacks attributed to other species. However, bull sharks are not true freshwater sharks (unlike the river sharks of the genus Glyphis).