(OCEANS) FLORIDA — Tens of thousands of sharks have recently been spotted along the Florida coastline. Beaches around the area have been closed while the sharks migrate north. This annual shark migration is taking place a little earlier than usual this year, and marine biologists may know why. Read on to learn more about this massive shark swarm. — Global Animal
A spinner shark jumping out of the water. Photo Credit: Ronald C. Modra, Getty Images
A spinner shark jumping out of the water. Photo Credit: Ronald C. Modra, Getty Images

Discovery News, Tim Wall

Shark Week came early to Florida. Tens of thousands of sharks have been spotted from Boca Raton to Jupiter, Fla., as they migrate north along the coast, reported WPTV. Officials closed area beaches. Marine biologists noted the annual migration is occurring earlier than usual this year, possibly due to warmer ocean temperatures.

Most of the passing predators are spinner sharks (Carcharhinus brevipinna), which grow to 10 ft. (3 m) long. The sharks earned their name from the bestial ballet they perform while hunting. The sharks attack schools of fish by racing towards the surface, then twirl as they leap from the water while grabbing their prey from below.

Spinner sharks live along coasts around the world. However despite their wide distribution the shark is listed as near threatened or vulnerable in parts of its range by the International Union for the Conservation of Nature. The sharks are hunted for their meat as well as for their fins which are used in soups.

Humans are a larger threat to spinner sharks than vice versa. WPTV reported that most of the five to six bites that occur in Florida waters each year cause only minor injuries. Spinner mostly hunt fish and generally ignore mammals. Their teeth are pointed and designed for gripping slippery fish, rather than shredding flesh.

Great white sharks (Carcharodon carcharias) pose a more serious threat, although they cause far fewer deaths each year than family dogs. To keep tabs on great whites and other sharks, the Ocearch Global Shark Tracker allows user to follow sharks that have been tagged with radio transmitters. For example, right now, a nearly 15-foot, 2,500-pound great white named Genie plies the waters off South Carolina.

More Discovery News: http://news.discovery.com/animals/sharks/sharks-along-florida-coast-cause-beach-closures.htm