[Coral-List] Coral bleaching

[Ribanataake T. Awira]

Dear All,

I am working with the Fisheries Division in the Republic of Kiribati and 
as one of the networking group for corals I wish to seek assistance on 
the effect of chlorine on corals.

Last week we went on our monitoring trip surveying corals on an island 
where a a Live reef fish operation (fishing for live groupers and wrasse 
for the live reef fish trade in Hong Kong) was active.  During our 
monitoring work many corals were seen bleaching from 10 to 30 m on all 
the known sites fished by the company.  The company is a joint venture 
company between a local and the Hong Kong based company and our worry is 
that they might be using chemicals to stunned grouper and wrasse.  A 
Solution sample was collected and tested at USP and the result shows a 
cyanide free results.  The testing was only made on one chemical and 
since cyanide testing is negative, we suspect that they are using other 
chemicals such as chlorine and others.  The solution smells like 
detergent but we need to confirm this from USP.

My question if the group can assist is as follows;

1.  What is the effect of chlorine on corals?
2.  Are there any other chemicals that can be used to anaethesize fish 
and what are their effects to corals?
3.  At what depth do bleaching caused by a rise in temperature and 
salinity is prominent?

I appreciate the group contribution on the above matter please.

Regards
Rib