The anglers, aboard a 45-foot yacht named Silver-Rod-O, faced a double assault: The crew of the Venezuelan purse-seiner (pictured) threatened to plow over the yacht, but decided instead to encircle the vessel with its net.
"Several explosives landed within 50 meters of the boat," Gary Carter, the yacht's owner, said of the recent incident, which prompted an outcry from a Florida-based fisheries conservation organization and an investigation ordered this week by Costa Rica President Laura Chinchilla.
The anglers were able to flee and return unharmed to the Costa Rican port of Garza. But the incident is troubling because it's not isolated. It has happened twice to Carter, who lives in Duluth, Ga., but keeps his boat in Costa Rica, and it has happened at least nine times to other sportfishing captains during the past two years off the west coast of the Central American nation.
"The Costa Rican government has to do something to show these foreign seiners that this sort of behavior will not be tolerated before someone gets injured or killed out there," said Joan Vernon, a board member for The Billfish Foundation, which filed the complaint to Chinchilla and also notified the U.S. Ambassador to Costa Rica.
These incidents have typically involved foreign-registered seiners licensed to fish in Costa Rican waters. Their crews, like those who operate sportfishing yachts, are looking for dolphins, which often travel with tuna and other game fish.
If large schools of fish are present and if sportfishermen are in the way, the seiners will try to force them to leave so the nets can be deployed.
The explosive devices are "tuna bombs" dropped around the schooling fish -- usually yellowfin tuna -- to contain them in a small area, while a seine net is set around the school. The bombs are illegal in Costa Rica but apparently are still used by some commercial fishing fleets.
Chinchilla said Tuesday that she has ordered a probe into the Aug. 1 incident.
Carter said the previous encounter he had with seiners was on July 31, 2008. A guest was fighting a large tuna when the seiner Lautaro arrived and deployed a helicopter to make close sweeps and try to force the yacht off the tuna school.
While the guest was struggling to land the tuna, Carter said, "the seiner dropped its net to fully encircle us. About 45 minutes later, my guest landed the tuna and the Lautaro refused to let us out of the net for well over an additional hour."
Carter said explosive devices were not used in the 2008 incident. Of the more recent incident, when asked how loud and powerful the bombs were, Carter answered:
"I cannot say how powerful the incendiary devices are. With all of the noise from my boat and of the tuna seiner with its speed boats, and the helicopter, it was not possible to hear a blast. We could only see the smoke billowing from the water wherever they hit."
The Billfish Foundation, a nonprofit group that works with governments around the world to try to conserve billfish populations, has been trying to persuade Costa Rica, one of the world's premier sportfishing destinations, to take a tougher stance on commercial fishing.
The group recently completed a study that found sportfishing-related tourism generates $599 million annually for the Costa Rican economy.
"If Costa Rica won't address this sort of outrage and also take better care of the marine resources like sailfish and marlin that drive this economic engine, they will find people moving elsewhere and taking their money with them," said Ellen Peel, president of the Billfish Foundation.
Peel noted that Costa Rica's southern neighbor, Panama, recently outlawed purse seining within 200 miles of its coast. Guatemala, which is to the north of Costa Rica, does not allow seiners inside of 110 miles.
-- Pete Thomas
Photos of the Venezuelan seiner and helicopter used to harass those aboard the Silver-Rod-O courtesy of Gary Carter