MIAMI, July 26 (UPI) -- They don't strike as often as lightning or even sharks, but jumping sturgeon have become something to look out for, especially on Florida's famed Suwannee River.
Two people have been injured in separate incidents so far this year when sturgeon up to 6 feet long and weighing well over 100 pounds jumped their boats.
Gainesville elementary school principal Lacy Redd, 34, suffered a collapsed lung when a 130-pound to 150-pound fish jumped into her boat Memorial Day weekend and knocked her unconscious.
Danny Cordero, 19, of Perry, Fla., was riding a personal watercraft with his girlfriend when a sturgeon jumped and knocked them both off the machine.
"I don't remember anything. My girlfriend said it was like hitting a brick wall," Cordero said. "She saw me lying face down in the river. I had blood all over me. It cracked my teeth and chewed up my gums."
A picture of a 127-pound sturgeon made the news in March when it washed up on shore. Sturgeon travel from the Gulf of Mexico into coastal rivers to spawn in the spring and summer, heading back to the Gulf in the fall.
There are no statistics on collisions between sturgeon and boaters, but some people on the Suwannee say they are on the rise.
University of Florida researcher Frank Chapman says that the number of sturgeon in the Suwannee hasn't increase in 20 years, but boat traffic has. He estimates there are 5,000-8,000 sturgeon in the river.
A sheriff's deputy was knocked down by a sturgeon in 1999; Larry Foshee of Pensacola, Fla., has had two encounters on the Yellow River near his home in the last six years; and Carol Brown, 50, had to have plastic surgery 10 years ago when a sturgeon broke her nose.
It is not unusual for a sturgeon to jump, but no one seems to know why they do it.
"We don't know. They just jump," Chapman said. "They jump a lot. It's more common than you think."
Sturgeon are a threatened species, so even if they injured somebody the victim can't legally take them home for a meal or two.
It also means the ones in the wild can't be used for their caviar, but there are aquaculture operations that produce the gourmet item.
Chapman said he has seen Gulf sturgeon as large as seven feet and 178 pounds, but they are small by comparison with other populations. The white sturgeon found along North America's northern Pacific coast can weigh 1,300 pounds. The beluga sturgeon in the Caspian Sea can weigh as much as 3,800 pounds.
They can be more damaging than other fish because they have their bones, known as scutes, on the outside. They are not only hard, they are "sharp as a razor," Chapman said.