They are superb athletes. Blue marlin can hit 60 mph in short bursts. They can leap from the ocean and fight experienced fishermen from dawn to sundown. Their immense cruising range -- they've been known to travel 1,200 miles in a few days -- has confounded scientists trying to learn their life histories.
The powerful predator that gave its name to South Florida's Major League Baseball team also faces severe threats. Fishing fleets from Japan, Taiwan, South Korea, Spain and Brazil have devastated populations of blue and white marlin, catching thousands of them accidentally in the quest for valuable swordfish and tuna.
Now scientists in South Florida are engaged in an intense effort to learn the habits of marlin, sailfish and other billfish so they can design ways to protect them. And they hope the success of the Florida Marlins on the field brings publicity to the cause of marlin in the ocean.
"We're very excited," said Ellen Peel, president of the Billfish Foundation, a Fort Lauderdale-based group that promotes research and conservation of marlin, sailfish and swordfish, who plans to attend tonight's World Series game. "It raises awareness with the average citizen that this is a grand species, the top of its class. There's a reason they named it for the marlin. They're the eagle of the ocean. The didn't name it for the mullet."
But like grizzly bears, panthers and other top predators, marlin are struggling to survive. A study last summer in the journal Nature found that commercial fishing had wiped out 90 percent of the marlin, tuna and other big fish during the past 50 years.
About 95 percent of marlin mortality comes at the hooks of tuna longline fleets, experts say. Fishing boats cruise the Atlantic in search of swordfish and yellowfin tuna, which tend to swim in the same areas and seek the same prey as marlin. The boats set out lines that are miles long, bearing thousands of baited hooks. As they haul them up, dead marlin drop to the deck, an accidental annoyance in place of the more valuable food fish.
"They're in trouble," said Robert Cowen, a professor at the University of Miami's Rosenstiel School of Marine & Atmospheric Science. "The white marlin, in particular, is in very serious trouble."
Hoping to find ways to protect them, scientists are trying to learn as much as they can about these huge but mysterious fish. At the University of Miami, scientists have begun penetrating a basic mystery of marlin biology, their spawning areas. Because they travel so far, marlin have thwarted efforts to learn much about their lives, Cowen said. And it's important to learn their spawning grounds so authorities can know which areas need to be protected and what time of year to protect them.
By searching the waters for young marlin larvae -- at most 3 days old -- researchers have discovered two spawning grounds for blue marlin. These are the southeastern Bahamas around the mouth of Exuma Sound and south of Miami in the Florida Straits. They found a spawning area for white marlin at Punta Cana in the Dominican Republic.
"If you know more about where and when fish are aggregating to be spawning, you provide a tool to managers to try area closures," Cowen said. "You don't want any longlining in those areas during those spawning times."
To learn where marlin go during their long journeys, scientists at UM and the National Marine Fisheries Service attach satellite tags to adult fish. The tags collect information on depth, temperature and location. After 30 days, they detach themselves from the fish, float to the surface and beam the information to a satellite, which sends the information to the National Marine Fisheries Service laboratory in Miami.
By knowing their movements, scientists can design ways to save them from the longline fleets. They may discover times when certain areas are thick with marlin but sparse in tuna. Clearly these would be places to discourage longlining, Cowen said.
Each satellite tag costs $4,000. Scientists have set up an Adopt-a-Billfish program to entice people to pay for tags. Information can be obtained from the Billfish Foundation, at www.billfish.org.
While marlin remain a target fishing enthusiasts, scientists say that has little effect on the species. The catch-and-release conservation ethic has caught on, along with the replacement of j-hooks with less harmful circle hooks. Marlin still die from the ordeal of being caught, hauled up and thrown back into the ocean, Cowen said. The stress exhausts them, leaving them easier prey for sharks, he said. But he said the majority survive.
Capt. Tom Zsak, who operates a charter boat out of Bahia Mar in Fort Lauderdale, said he has noticed a decline in both blue and white marlin during the past 30 years.
"We used to catch a lot of white marlins off Fort Lauderdale," he said. "Now you're lucky if you see one or two a year."
Blue marlin appear more often, but they're smaller. About 10 years ago, Zsak caught a 1,245-pound blue marlin off Panama. Today, they tend to range from 150 to 300 pounds, he said. But then, they've always been challenging, he said. He once fought one for more than 11 hours.
"They're elusive; they're just born killers," Zsak said. "You can't find anything prettier than a blue marlin."