Starting in mid-March, there has been a deep-sea phenomenon in the Gulf Stream between Florida and the Bahamas. Huge whale sharks and a variety of sea turtles are being spotted almost daily.

Swimming with the whale sharks and sea turtles is an entourage of gamefish, including cobia, dolphin, tuna and wahoo. There are also remoras attached to the whale sharks and sea turtles.

The first time I witnessed the spring whale shark migration was years ago, offshore about midway between Lake Worth Inlet and St. Lucie Inlet.

Whale sharks are no cause for alarm because they are harmless plankton eaters; plankton being tiny — almost microscopic — free-floating marine organisms.

Reports of whale shark and sea turtle sightings began in mid-March during the Capt. Bob Lewis Billfish Challenge off Miami Beach. Boats that ventured offshore in 500 to 800 feet of water, were first to call in whale sightings to Capt. Dan Kipnis, who was handling radio communications in the tournament.

Since then, hardly a day goes by that a skipper aboard a charter boat or private boat doesn't report seeing whale sharks and sea turtle. For some reason, the turtles and whale sharks are being sighted in the same general area.

The sightings are going on, even as you read this. For how long they will continue, no one knows. My guess is, probably during most of April.

Capt. Quinton Dieterle on the boat Cutting Edge, reported seeing a sea turtle in 800 feet of water, trailed by a school of dolphin.

"We caught 30 dolphin up to 20 pounds from around the turtle," Dieterle said.

The skipper of the boat Top Hatt found a jumbo leatherback turtle offshore, trailed by a school of large cobia. He radioed Capt. Mark Houghtaling on the boat Magic Fingers, to come and try for the cobia.

"First, we saw the turtle

... it was huge," Houghtaling said. "From the flying bridge, the leatherback looked the size of a billiards table. There were so many remoras on the turtle's back, we couldn't get a pilchard bait to the cobia because the remoras were eating our baits.

"Finally, two large threadfin herring were cast out and two cobia were hooked. One of the cobias weighed 60 pounds and the other was 46 pounds. The 46-pound cobia was tagged."

Read Hendon at the Gulf Coast Research Lab said the cobia was originally tagged off Pensacola Beach by Capt. Harold Loeffler. The cobia was 44 inches long when it was tagged. It was released last April 18. When it was re-captured in March, off South Florida, it was 47 1/2 inches long. It had been swimming free 333 days and had traveled 655 miles.

As if the whale sharks and sea turtles were not enough to keep the marine radios busy, two boats fishing last week off Miami Beach called in a sighting of a huge school of sharks.

The two captains were Jimbo Thomas on the Thoms Flyer and Craig Fountain on Fine Line.

"At first, they thought splashing at the surface was caused by a school of tuna," Thomas said. "When we got close, we could see it was a giant school of sharks feeding at the surface.

"They looked to me like blacktip sharks. The sharks appeared to be about the same size . . . 5-to 6-feet long."

The two fishing parties watched the sharks for 20 minutes.