Recovery from cyanide poisoning

[Peter N. King]

     As you may know, the Asian Development Bank, World Bank, GEF, AusAID, 
     JICA and the Government of Indonesia are formulating a major Coral 
     Reef Rehabilitation and Management Project in Indonesia and we seek 
     the cooperation of Coral-List members in providing the technical 
     backstopping for this ambitious undertaking.

     One of the unresolved areas debated in Indonesia and the Philippines 
     is the extent to which coral reefs can recover from cyanide poisoning 
     associated with illegal fishing for the live fish trade.  In a 1986 
     paper, Peter Rubec noted that researchers in the Philippines were 
     divided on the question of whether squirting sodium cyanide at coral 
     reefs caused their death.  "Scleratinian corals reacted by retracting 
     their polyps and exuding a mucoid substance.  In a matter of minutes, 
     the polyps came out again positioned in the usual way."  "A second 
     dose was given four months after the first. A day after the second 
     application, all corals appeared to have recovered.  But when the 
     stations were revisited three months later, all corals in the test 
     quadrats were dead."  The results may have been confounded by an 
     outbreak of COTS (Acanthaster sp.).  

     Can anyone explain a mechanism that would allow the corals to survive 
     for four months after the first dose, apparently recover after the 
     second dose, and then appear to have died 3 months later?  What have 
     other field or laboratory tests shown in relation to recovery rates 
     following cyanide poisoning? 

     Peter King
     Asian Development Bank
     Manila, Philippines