In last week’s blog we talked about the pufferfish and it’s lethal tetrodotoxin as a murder weapon.  Today I’d like to discuss a couple of other interesting sea toxins that could be used as instruments of murder to kill off characters in your stories of intrigue.

Saxitoxin:  This toxin is produced from marine plankton contaminated with toxic algae such as, Blue-green algae and Red Tide (as discussed in my blog on harmful algae blooms).  Saxitoxin is abbreviated as STX and is alternately referred to as Paralytic Shellfish Toxin (PST) or Paralytic Shellfish Poisoning (PSP).  This toxin accumulates in shellfish (clams, mussels and scallops) when they consume tainted plankton.

This chemical is highly toxic and can kill in very small oral doses (as little as 0.5mg for a normal sized person).  If the toxin is injected or applied to an open wound, only one-tenth of that oral dose would be needed to kill (a minute 0.05mg).

Poisoning by inhalation, however, requires larger doses (about ten times the oral dose), but that’s still a mere 5mg and certainly smaller than some other aerosolized poisons.

Such small deadly doses make saxitoxin a major cause for concern as a weapon of terrorism, but more importantly this toxin can be synthesized in a lab rather than harvested from infected shellfish for potential use as a chemical weapon.

Saxitoxin is about 1000 times more toxic than sarin nerve gas.  In fact, saxitonin already has a military history.  The United States previously designated it as a chemical weapon and provided saxitoxin-impregnated needles to elite US soldiers as suicide tools for use if captured and tortured for top-secret information.

It has been said that U2 pilot Gary Francis Powers had a hollow silver dollar on his person when he was shot down in 1960 over Soviet airspace and that it contained an STX-impregnated needle to use at his discretion.

The symptoms of PST and PSP involve paralyzing the nervous system but the unset involves a “flaccid paralysis”, leaving the victim calm, relaxed and conscious before paralysis sets in.  Death ultimately results from respiratory failure when the muscles of the diaphragm cease functioning.

Ciguatera:  This food borne toxin causes illness in humans from contaminated reef fish.  The source of the contamination is from marine microalgae called dinoflagellates found in tropical and subtropical waters and which transfer to fish as they feed.  Since larger fish feed on smaller ones (and the smallest consume the microalgae), the toxin moves up the food chain.  Predator species near the top of the chain are more likely to cause illness because of the greater concentration of toxins from multiple feeds on contaminated fish.

The toxin is odorless and tasteless.  It’s very heat-resistant, so conventional cooking does not detoxify the seafood.  The good news is that this toxin produces illness more often than death.

The symptoms of ciguatera poisoning are GI distress (nausea, vomiting) and a variety of neurological symptoms (such as, tingling fingers and toes, vertigo and hallucinations).  An interesting neurological effect is that the victim may find that cold things feel hot and hot things feel cold.  The poisoned person may even be misdiagnosed with multiple sclerosis (MS).

Even though the toxin may not be lethal, there is no cure and symptoms can range from short-term to long-term.  The victim may recover in days to weeks but the effects of ciguatera poisoning may last for years (even 20 years or longer) and can cause long-term disabilities (coordination and communication issues).  Most recover slowly over time, but it should be noted that during the recovery process exercise could trigger onset of further symptoms.  A particularly nasty villain in your novel might get what he deserves with such a toxin.

Fortunately, there are lab tests to detect the presence of this toxin and Liquid Chromatography-Mass Spectrometry is most often used.  Previous to this science, “folk detection” was used to detect contaminated fish: ancient cultures determined that flies would not land on such fish and silver coins were put under the scales of a fish—if the coin turned black, the fish was not eaten.  One can assume that the owner was happy to have a tarnished coin to spend on something other than a funeral.

As with my previous postings on murder weapons, I hope these thoughts have stimulated your creative juices to plan and plot unusual murder scenarios that will delight and hold the interest of your readers.

Thoughts?  Comments?  I’d love to hear them!