Cyanide Fishing - Mechanism

Mechanism

In seawater sodium cyanide breaks down into sodium and cyanide ions. In humans, cyanides block the oxygen-transporting protein haemoglobin; the haemoglobin in fish is closely related to that of humans, and can combine with oxygen even faster. Through the irreversible combining of cyanide ions onto the active structural domain, oxygen is prevented from reaching the cells, and an effect similar to carbon monoxide poisoning results. Coral polyps, young fish and spawn are most vulnerable; adult fish can take somewhat higher doses. The use of cyanide is known to cause mortality on laboratory corals in measured doses, however these data are very difficult to quantify in regard to wild populations. In humans ingestion or breathing in of cyanide leads to unconsciousness within a minute; asphyxiation follows. Lower doses lead to temporary or permanent disability and/or sensory failure. This is a constant danger for the fishermen; there are many local accounts of such "occupational accidents", but such incidents are not recorded in official statistics or statements.