New method for detecting cyanide in marine fish

[JennM]

http://www.practicalfishkeeping.co.uk/p ... p?news=625

New method for detecting cyanide in marine fish
Chinese scientists have reported a new method for detecting the presence of cyanide in marine fishes caught for both the aquarium and food trades.

While the aquarium trade is taking every effort to ensure that all marine fishes sold are hand caught using nets, it's possible that some cyanide-caught fish may be slipping through undetected.

Cyanide used to be used to catch a small percentage of marine fish in the 1960s, but its use has always been frowned upon because it damages reefs and can cause fish to die, often weeks after they are exported.

Aquarium groups, such as the Marine Aquarium Council, have been lobbying for many years to minimise the number of fish caught with cyanide that make it into the aquarium trade, and in most countries the process is now illegal.

The problem is that cyanide is difficult, expensive and time consuming to detect. The existing tests may also not be completely specific to cyanide and may not be sensitive enough to spot dodgy fish that have been caught using this barbaric technique.

The new technique, which has been developed by a team of three researchers from the Hong Kong University of Science and Technology describes an ultra sensitive method and takes a critical look at the available methods.

For more details see the paper: Mak, KK., Yanase, H. and R. Renneberg (2005) - Cyanide fishing and cyanide detection in coral reef fish using chemical tests and biosensors. Biosens Bioelectron. 2005 Jun 15;20 (12): 2581-2593.
More at: PFK (Thu April 28, 2005, 6:34 pm)

 

[Anonymous]

http://www.practicalfishkeeping.co.uk/pfk/pages/item.php?news=625


Aquarium groups, such as the Marine Aquarium Council, have been lobbying for many years to minimise the number of fish caught with cyanide that make it into the aquarium trade, and in most countries the process is now illegal.

I thought the idea was to stop cyanide use.

Although a nice article, it would have been nice to have been given just a tad more information. Let's hope the new testing, is worth the cost of developement.



As an aside......A few weeks ago, a fellow local reefer claimed a coral he'd recently purchased, died from cyanide. Claimed to have had it tested at the local university. :roll:

 

[clarionreef]

Sally,
The article was well meaning I'm sure, but wrong on the most basic of things.
1. MAC does not lobby to minimize cyanide use.
They cover for the main players in fact...and provide 'play and pay get out of jail cards' for them!

No group has done more to preserve and perpetuate the status quo then they...lulling the mildly interested to sleep while alienating everyone who knows whats going on!

2. " While the aquarium trade is taking every effort to insure that fish are hand caught..." dead wrong...they don't even have the nets yet...[ see thread 2 subjects down ] after years of embarrassment.

3. Cyanide was used to catch a small amount of fish in the 60's....wrong again. It was a large amount and has increased along with the number of net catchers!

But, if the test really works...and would actually be implemented, it would reveal that the exporters that have been certified have plenty of cyanide fish in their inventories and always have.

It would be a God-send if it actually worked....
Steve

 

[Anonymous]

Steve, that's what I was getting at. Been in here long enough to know whats what. The word "minimise" used in conjuction with MAC just sorta stuck in my throat somewhat.

I only wished that the article itself had given more information on the actual testing. What was involved with it. I guess I'll have to do some hunting around to see if I can find the paper on line some where.

I do agree, that if it works and is implemented, it would be a God-send.

 

[clarionreef]

Sally,
Heres the study they're talking about.

http://lbxml.ust.hk/th_imgo/b810475.pdf

Steve

 

[Anonymous]

-deleted- I was fully unaware that it was improper to post referenced citations from a thesis.

 

[naesco]

I would like a few scientists on this board to comment on this test.

When will this test be used stateside to ensure that every fish imported into the country is free from cyanide and those who continue dealing in cyanide are caught and prosecuted?

 

[PeterIMA]

I read the postings pertaining to the Ph.D. Thesis by Ka Wai Mak concerning cyanide testing done at The University Hong Kong of Science and Technology under Dr. Renneberg. Dr. Renneberg was funded by the Marine Aquarium Council (and other sources).

I find it disturbing that SciGuy (Mr. Morey) felt he had a right to quote information from a copyrighted thesis. He selectively chose to quote passages that were critical of the CDT Standard Operating Procedures (SOP) used by the International Marinelife Alliance (IMA)-Philippines. These quotes seem to reflect Mr. Morey's pro-MAC bias.

Mr. Morey is familiar with a review of the IMA's SOP sponsored by the MAC conducted in 1999. That report incorrectly concluded that the CDT methods were unreliable. A 30 page rebuttal by the IMA showed that the consultant who tried to repeat the SOP methods was incompetent. Likewise, I must conclude that the attempt by Dr. Ka Wai Mak to copy the IMA's SOP methodology is also biased.

Ms. Mak never bothered to contact the IMA to obtain the correct IMA CDT SOP manual. She cites an 8 page SOP manual, when in fact the original manual used by the IMA's six CDT laboratories is 26 pages long. I suspect that Ms. Mak used a document that describes some features of the SOP which was given out at a Live Reef Fish Workshop held in Hong Kong in 2000. If that is what she followed, it is not surprizing that she was not able to obtain reliable test results. It was not a test manual, just an information brochure.

The lower range of detection of the Ion Selective Electrodes is 0.03 mg per liter (ppm). I find it very odd that Ms. Mak concluded that when she used the ISE methodology used by the IMA (and by other organizations like the American Society of Testing and Materials, US Environmental Protection Agency, and the American Public Health Association) she could not detect cyanide ion levels below 0.26 ppm. Like the previous consultant to the MAC she seems to have changed the apparatus and other aspects of the IMA SOP for measuring cyanide ion concentrations.

The IMA has 48,000 CDT test results obtained by IMA's chemists from 1993 to 2001 in the six BFAR-sponsored CDT laboratories. They attest to the seriousness of the problems associated with the uncontrolled use of cyanide for fishing that has contributed to the destruction of Philippine coral reefs. At the time the IMA did the testing, it had about 80 staff involved in the monitoring and testing of both aquarium and food fishes throughout the Philippines. There is no doubt that cyanide was (and still is) used for destructive fishing in the Philippines. To suggest that these test results were wrong is libelous. The IMA plans to take action against those who have defamed its reputation concerning these matters.

Peter J. Rubec, Ph.D.

 

[Anonymous]

I read the postings pertaining to the Ph.D. Thesis by Ka Wai Mak concerning cyanide testing done at The University Hong Kong of Science and Technology under Dr. Renneberg. Dr. Renneberg was funded by the Marine Aquarium Council (and other sources).

I find it disturbing that SciGuy (Mr. Morey) felt he had a right to quote information from a copyrighted thesis. He selectively chose to quote passages that were critical of the CDT Standard Operating Procedures (SOP) used by the International Marinelife Alliance (IMA)-Philippines. These quotes seem to reflect Mr. Morey's pro-MAC bias.

I am indifferent to MAC. I have no current ties to them and have no strong opinion regarding their efforts.

Mr. Morey is familiar with a review of the IMA's SOP sponsored by the MAC conducted in 1999. That report incorrectly concluded that the CDT methods were unreliable. A 30 page rebuttal by the IMA showed that the consultant who tried to repeat the SOP methods was incompetent. Likewise, I must conclude that the attempt by Mr. Ka Wai Mak to copy the IMA's SOP methodology is also biased. Mr. Mak never bothered to contact the IMA to obtain the correct IMA CDT SOP manual. He cites an 8 page SOP manual, when in fact the original manual used by the IMA's six CDT laboratories is 26 pages long. I suspect that Mr. Mak used a document that describes some features of the SOP which was given out at a Live Reef Fish Workshop held in Hong Kong in 2000. If that is what he followed, it is not surprizing that he was not able to obtain reliable test results. It was not a test manual, just an information brochure.

The lower range of detection of the Ion Selective Electrodes is 0.03 mg per liter (ppm). I find it very odd that Mr. Mak concluded that when he used the ISE methodology used by the IMA (and by other organizations like the American Society of Testing and Materials, US Environmental Protection Agency, and the American Public Health Association) he could not detect cyanide ion levels below 0.26 ppm. Like the previous consultant to the MAC he seems to have changed the apparatus and other aspects of the IMA SOP for measuring cyanide ion concentrations.

The IMA has 48,000 CDT test results obtained by IMA's chemists from 1993 to 2001 in the six BFAR-sponsored CDT laboratories. They attest to the seriousness of the problems associated with the uncontrolled use of cyanide for fishing that has contributed to the destruction of Philippine coral reefs. At the time the IMA did the testing, it had about 80 staff involved in the monitoring and testing of both aquarium and food fishes throughout the Philippines. There is no doubt that cyanide was (and still is) used for destructive fishing in the Philippines. To suggest that these test results were wrong is libelous. The IMA plans to take action against those who have defamed its reputation concerning these matters.

Peter J. Rubec, Ph.D.

Thank you for your rebuttal. Perhaps the analytical procedure used by Mr. Mak did differ from what the IMA provided to BFAR based upon your comments. Didn't Mr. Mak contact you prior to his experimentation? Please note that I did not suggest that the IMA test results were wrong. In fact, I didn't suggest anything other than questioning why there was at least one possible deviation from the expected during Mr. Mak's study. Isn't one typically looking for cyanide resulting from sodium cyanide exposure in doped fish and not potassium cyanide exposure?

 

[PeterIMA]

Reply to SciGuy,

Thanks for your comments about my posting.

1. No neither Dr. Mak nor Dr. Renneberg contacted the IMA prior to initiating their research. The IMA's SOP manual was provided to the MAC in 1999, and I would assume they (Mak and coauthors) could have obtained it from the MAC. However, the Ph.D. thesis of Dr. Karen Mak implies that she did not have the correct SOP manual (as explained in my previous posting).

2. Sodium cyanide is used for fish collecting in the Philippines. Both sodium cyanide and potassium cyanide are used in Indonesia. I don't believe that using potassium cyanide for their research would make much difference. Both compounds dissolve in seawater. The cyanide ion hydrates to form hydrocyanic acid (HCN) in seawater. The HCN is absorbed across the gills of the fish. In both cases, it should be possible to measure cyanide ion after the fish is dissolved and the HCN vapor in the reflux distillation apparatus is captured in a tube containing sodium hydroxide solution.

3. The ASTM procedure followed by the IMA chemists requires that certain chemicals be added to deal with interferring substances. There is no indication in the thesis document that indicates that Ms. Mak carried out these procedures. There are other concerns about this research, that will be presented later.

4. The IMA's main concern is that research was conducted that came to incorrect conclusions concerning the IMA Standard Operating Procedure (SOP) for measuring cyanide ion concentrations in marine fish.

Peter Rubec

 

[naesco]

Dr. Rubec

Is it too early to comment on their test?
Also I am surprised by the date. I would have thought that if this was the Hong Kong MAC test it would have been out much later than 2003.

 

[clarionreef]

Wayne,
As Hong Kong is the worlds largest consumer of cyanide caught food fish, perhaps they were inspired to come up with a test while everyone kept eating cyanide fish taken in other countries.
They more then anyone should develop a real test to effect change in this institutionalized cyanide fishing industry of theirs....where their own people eat the stuff.
Steve

 

[PeterIMA]

Steve, While I agree that Hong Kong should get serious about cyanide testing, I object to your insinuation that the IMA/BFAR CDT was not "a real test" for cyanide. My quick perusal of the Thesis being discussed indicates that the enzyme-based test evaluated did not have practical application (more reseach was needed).

PS-How long did you know about this work, before you posted on Reefs.org?

Peter Rubec

 

[clarionreef]

Peter,
By real test I ment one that works and is actually employed to work. Period. Whereever it comes from.
I certainly didn't think of a choice in tests but any genuine one that works and could be in play would be good to see.
If the IMA one was stolen, plagerized or wrongfully accused it is not surprising. Thats how they work is it not?
This stuff is a business not a movement.
Still, even a real test would have to be implemented honestly and there in lies the rub. BFAR in the Philippines certainly has cooled to the idea of using a CDT to go after anyone have they not? Real or not.
An honest, real test still has the bigger hurdle of being used honestly. Switched samples, lost samples, falsified results etc. typify the BFAR employment of the CDTs in the past.
One would hope that Hong Kong would not continue a corrupt tradition.
The fact that so many of the fish they will test were smuggled in the first place suggests that they are hardly sincere anyway.
Perhaps the good scientists are sincere....but the worth of their work still lies in the honest implementation of it. Businessmen and their political 'allies' will all have their input.
Steve

 

[JeremyR]

Mmmm.. tasty.. I suddenly have an urge to go to a live fish sushi bar in hong kong.