By GABRIEL MARGASAK, Scripps Howard News Service

SEBASTIAN, Fla. -- A picture was worth a young dolphin's life.

Researchers at the Harbor Branch Oceanographic Institute in Ft. Pierce, Fla., were taking pictures for their Indian River Lagoon dolphin identification program when they noticed a calf they know as C1Bitt with a belt from an engine wrapped around it.

They call it the "Unknown Shipwreck."

"That's a lot of mystery right there isn't it," said Capt. Doug Pope, a veteran treasure hunting and salvage expert.

Pope's crew and vessel, the Polly-L, will be hunting off St. Lucie County, Fla., this week for a ship believed to part of a 1715 Spanish fleet that sank in a storm with holds full of treasure.