Living Sanibel: Nurse and lemon sharks found inshore, offshore waters of SW FL
Although the nurse shark looks formidable, it poses little danger to humans. It lacks large teeth, instead relying on rows of smaller teeth that crush its prey instead of biting through it. It is a beautiful fish, with a large head and attractive light brown skin. It is capable of sitting motionless on the bottom, which can sometimes startle local snorkelers. It generally swims away when approached, but should be observed with caution since it can deliver a nasty, vice-grip like bite.
The nurse shark is rarely found along the beaches. It inhabits the back bay and is a fairly common by-catch of inshore and nearshore tarpon fisherman. It is never targeted for catch-and-release fishing because its fight is anything but dramatic. It basically comes up like an old boot, with short, slow runs, no aerial acrobatics whatsoever, and an end game that leaves the angler bored at best. No one harvests the nurse shark, not even for its fin. As a result the nurse shark is one of the least endangered of all the major sharks.
It is a nocturnal bottom feeder that dines on crabs, octopi, squid, and clams. It eats carrion and small finfish, but its mouth is too small to consume stingrays or larger fish such as grouper. Juvenile nurse sharks are preyed upon primarily by other more aggressive sharks such as tigers, bulls, lemons, and hammerheads. The adults, because of their size, are seldom targeted. It is common only to the western edge of Africa and the subtropical shores of North and South America, including the Mexican and California coastline.
Although the lemon shark can grow to 10 feet, it is not considered a man-eater. The International Shark Attack files, located at the ichthyology department at the University of Florida, has recorded only 10 unprovoked attacks by lemon sharks (going back more than 100 years), and none of these attacks ever proved fatal.
The lemon shark is approaching near-threatened status chiefly as a result of commercial over-harvesting, with shark finning being the primary problem. Lemon shark meat is said to be excellent; its skin can be used for shark leather; and the liver pressed for vitamin oil. This combination of uses makes the lemon shark a highly prized target species and does not bode well for its future.
Around the islands catching a lemon shark is very common. Most are small, seldom measuring more than four or five feet long. The preferred bait for catching the lemon shark matches its diet: cut catfish, cut mullet, pinfish, and grunts. It also eats porcupine fish, stingrays, crabs, pelicans, seabirds, and crayfish. Juvenile lemon sharks are targeted by bull sharks and larger finfish. Adult lemon sharks are rarely attacked by anything other than larger sharks.
This is an excerpt from The Living Gulf Coast – A Nature Guide to Southwest Florida by Charles Sobczak. The book is available at all the Island bookstores, Baileys, Jerry’s and your favorite online sites.