Proceedings of the International Cyanide Detection Testing Workshop

of degradation on the scale of a reef. For
example, Mouse et al. (Mouse, Pet-Soede
et al., 2000) state that blast fi shing accounts
for a loss in live coral cover of 3.75 m 2 per
100 m 2 of reef each year (Pet and Pet-Soede,
1999), which is about 75 times more than one
estimate of cyanide impact, and still about 5–6
times more than the ‘worst-case’ estimate for
the loss of coral cover due to cyanide fi shing
for food fi sh.
Other Toxins Used to Catch Fish
Cyanide is the most widely used chemical in
marine fi sh capture. However, other poisons
are utilized as well. Clove oil (or eugenol in
its purifi ed form) is a moderately well-known
anesthetic for small fi shes and crustaceans
(eg. Soto and Burhanuddin, 1995; Munday
and Wilson, 1997; Erdman and Pet, 1999).
Quinaldine is another narcotic associated
with the ornamental industry. It is reported
to be less dangerous than cyanide, but
capable of killing fi sh during collection when
concentrations are high or exposure time is
long (Randall, 1987). Bleach, formalin, and
gasoline were reported to be used occasionally
to catch aquarium fi sh in Puerto Rico in the
early 1990s (Sadovy, 1992), but the extent to
which they are used elsewhere is not known.
There are no data available that quantify the
extent of use of these chemicals.
Non-Toxic Fish Collection
An alternative to fi shing with toxic substances
such as cyanide is to catch fi sh with small nets
or to use hook and line. Numerous regional
organizations train collectors in how to use
these non-destructive methods. Despite the
training, collectors have been slow to switch
to using nets because they can earn more
using cyanide. In some cases it is possible
to pay the collector a premium price for fi sh
caught in a non-destructive manner (Barber
and Pratt, 1997).
100
Existing Cyanide Detection Tests
Because of the fact that cyanide can damage
the marine environment and potentially
decrease the mortality of fi sh sold in the
commercial trade, the use of cyanide to
capture fi sh is illegal in nearly all countries
where it is commonly used. In order to enforce
the law and monitor the presence of cyanide
in fi sh, the International Marinelife Alliance-
Philippines (IMA) and the Philippine Bureau
of Fisheries and Aquatic Resources (BFAR)
have developed a cyanide detection test (CDT)
to determine the presence of cyanide in livecaught
fi sh. The American Analytical Testing
Laboratory supported the development of
the test (Mak, Yanase et al., 2005).
The fi rst CDT laboratory was established
at BFAR headquarters in Manila in 1992
and now includes six laboratories and three
monitoring inspection stations. The IMA
CDT uses ion selective electrodes (ISEs) to
detect the concentration of cyanide in the
distillate (Mak, Yanase et al., 2005, see Table
1). In brief, internal organs of a fi sh, where
cyanide is rapidly absorbed, are homogenized
with water in a blender. Then the homogenate
is strongly acidified in a 1-hour reflux
distillation. If cyanide is present in the sample,
it is liberated as hydrogen cyanide (HCN) and
absorbed into a sodium hydroxide solution.
Finally, the presence of cyanide in absorbing
solution is detected using ISE. Each CDT lab
is capable of running at least 20 tests per day.
Each test takes a total of 1.5 hours including
the procedures described as above. After the
test, the result is given back to the owner
of the source of the sample in the form of
certification (Barber and Pratt, 1997; Mak,
Yanase et al., 2005).
Possibilities to Improve Cyanide Detection
Tests
Recently, researchers from the University
of Hong Kong simulated and reviewed the