Dear EarthTalk : I heard of a practice called cyanide fishing, which is used mostly to collect aquarium specimens, but I understand it is also used to catch fish we eat. Isn’t this very unhealthy? --Phil Seymour, Albany, N.Y.

Cyanide fishing, whereby divers crush cyanide tablets into plastic squirt bottles of sea water and puff the solution to stun and capture live coral reef fish, is widely practiced throughout Southeast Asia despite being illegal in most countries of the region. The practice began in the 1960s in the Philippines as a way to capture live reef fish for sale primarily to European and North American aquarium owners--a market now worth some $200 million a year.