Keeping a saltwater aquarium is a challenging, though expensive hobby which has been growing steadily in popularity. But few aquarium hobbyists consider the origin of their fish when buying them. This is terribly unfortunate, since their growing demand for colorful, tropical fish is responsible for the destruction of coral reefs in Southeast Asia (particularly Indonesia and the Phillipines), by a process very few people have even heard of.

Most saltwater aquarium fish can't be bred successfully in captivity. They must therefore be captured live from the wild. Large, trawling nets are impractical for this purpose; a reef fisherman must dive and catch his precious specimens by hand in order to keep them in viable condition for sale. It's a skilled profession that requires months of practice to master. Many novice fisherman in the South Pacific don't want to take the time to learn these skills before receiving their lucrative rewards. So they take the easy solution, stunning fish with cyanide to make them easier to capture.

It's a simple process. A diver crushes a pellet or two of sodium cyanide, mixes it with water in a squeeze bottle, and squirts it directly into the coral. Immediately lethal in higher concentrations, the dilute cyanide solution is supposed to stun the fish hiding there so that the diver can remove and harvest them. But many die at the scene, others living only a short time afterward. The fish can't remove the cyanide from their bodies - it accumulates in their livers. A lethargic fish in a tank might be suffering from delayed cyanide poisoning, soon to convulse and die.

If it were just the fish, it might not be as big a problem. But divers are poisoning the coral itself with the cyanide they feed it. They're not just killing fish, but destroying coral that makes up the basis for the entire ecosystem. The poisoned corals die, leaving fish to seek shelter in their healthier neighbors, leading divers to poison those's a vicious cycle. Dead fish can be replaced relatively easily. If the reefs die, there won't be any more fish for a long time.

Cyanide is often found in fish seized by customs agents in their countries of origin, where cyanide fishing is technically illegal (though poorly enforced) and the fish therefore contraband. Still, many tainted fish pass through the system. More effective voluntary programs to test and certify cyanide-free aquarium fish are being implemented, with the hope that hobbyists' awareness of the situation will lead them to demand certified fish. As live fish cannot be tested, a random sampling of a shipment is taken, the fish being liquefied and chemically analyzed. A better method has yet to be found.

Information taken from an article in the July, 2001 Scientific American.

Log in or register to write something here or to contact authors.