Sodium cyanide is highly toxic, and has the effect of slowing or preventing respiration. The practice of collecting fish using this chemical is mostly confined to the reefs of Southeast Asia. Many of the fish collected do not survive. The cyanide also kills coral by poisoning the Zooxanthellae, which leads to the bleaching and death of the coral. (WWF, 2003)
Dynamite fishing viewed from the surface
Sodium cyanide being applied to a reef