Fishermen have illegally entered Cocos Island for a long time. They insist on trapping fish found in this protected area which consists of 12 nautical miles around the Cocos Island National Park.
They use a technique in which they strategically place floating objects in order to generate a shadow underwater. They hang a rope from it and attach bait. A few hours later they return to find a large number of fish were attracted to it.
The natural behavior of most fish is to camouflage for protection. They coexist and congregate under floating objects to hide in the shadows. Floating fishing devices often catch tuna, dorado and billfish.
This process is prohibited, even if the fishermen place the device inside the protected zone and wait for it to naturally move outside that zone with the currents.
Using these devices can have an effect on many species by removing natural predators and causing an unbalanced ecosystem.
2011 Costa Rican Times