Researchers tag six hammerhead sharks at Cocos Island, Costa Rica

August 4, 2005 – San Jose, Costa Rica
During the last week, researchers from the Shark Research Institute (USA) and PRETOMA (Costa Rica) tagged six hammerhead sharks with acoustic transmitters at Cocos Island.  Two receivers were also set up at the island to receive the signals from the tagged sharks.  This research will help determine if these sharks are residential at the island, 350 miles southwest of the Costa Rican Pacific coast or highly migratory and merely visit the island periodically, essential information to determine management priorities and strategies.
 
One whale shark, the world’s largest fish, was seen by the scientists; however, conditions made tagging impossible.  Placing satellite tags on whale sharks to determine their migratory patterns throughout the region will have to wait till the second trip to the island, in another 4 to 6 months.  (See links to photos below.)
 
Cocos Island is renowned as one of the few places left in the world where sharks are still fairly abundant, even though divers who have been diving at the island for years note that populations have declined significantly in the last 10 years.  This is a global trend stemming heavily from the increased demand for shark fins during the last 20 years.
 
“The long-term goal is fishing policies not only here in Costa Rica, but on a global level, that recognize the severe decline in fishery resources, and take steps to ensure the recovery of commercial resources, recovery of endangered species and the creation of sustainable fisheries,” says Alex Antoniou, Director of Operations of Shark Research Institute and one of the researchers in the project.
 
“Around the world fishermen themselves are calling for measures, such as no-fishing zones or certain no-fishing periods during the year, because they themselves realize that their future depends on sustainable management and protection of resources,” says Randall Arauz, President of PRETOMA and researcher in the project at Cocos Island.  “Solid scientific data coupled with the knowledge of fishermen are necessary for the creation of measures to protect breeding grounds and migratory routes of commercially important and endangered species, and manage fishing operations where resources still exist so that they don’t disappear.” 
 
Cocos Island and its surrounding waters are a Costa Rican National Park and UNESCO World Heritage Site.