VIDEO: Thousands of sharks spotted migrating along South Florida coast, beaches closed

PALM BEACH, Fla. -- - Beaches are closed to swimmers after thousands of sharks have been spotted swimming along South Florida shores.

Marine biologists have spotted tens of thousands of sharks from Boca Raton to Jupiter since the start of the month. They say the marine animals are moving north, after migrating south for the winter.

Our West Palm Beach sister station WPTV spotted hundreds of sharks swimming along Palm Beach this morning from their chopper.

On Tuesday off Midtown Beach, lifeguards spotted a school of spinner sharks moving through the area. The red flags quickly went up, meaning swimmers could not go in the water at that time.

Spinner sharks can be seen jumping out of the water and spinning, as they chase their prey through the water.

Although they're an interesting sight to see, sharks are quite dangerous to swimmers.

Doctors at a local medical center say they treat at least five to six shark bite victims a year. They say the injuries are usually minor, but even small shark bites can put victims at risk of infections.

To protect yourself from getting bitten by a shark, swim along beaches where lifeguards are present. Also, leave your jewelry on the shore. Scientists say sharks are attracted to silver, along with the colors yellow and gold.