Dangerous Creatures of the Sea
The sea covers 70 percent of the earth surface but contains disproportionately more space for living creatures of every kind. Man has always developed a close connection with the sea and for me the sea always beckons. However, the sea belongs not to us two legged humans but to the denizens of the deep and some of them have evolved to be highly dangerous when provoked or when eaten.
The Puffer fish, ocean sunfish or porcupine fish contains a poison called Tetrodoxin. Tetrodoxin causes muscular weakness and other effects on the body’s sensory systems. Symptoms such as salivation, sweating, chest pain, headache may occur Symptoms such as salivation, sweating, chest pain, and in the worse case generalized paralysis whilst being fully conscious may happen. We all know of the rather infamous Japanese practice of eating fudu, where skilled and certified chef would slice slivers of the puffer fish after having their poison glands washed and removed and diners would be warned to stop eating if they feel numbness around the mouth!! But do you know that some tribes have been known to use the poison to induce a sort of living dead (voodoo) state on it victims, burying them alive or declaring them dead only to have them “resurrect” as “zombies” when the effect of the poison is gone. (Assuming that the dose was just right not to kill them in the first place!!)
A bible verse describes a catastrophic event in Moses time and this probably happened in the Red sea. The Red sea is so called because of the frequent occurrence of Red tides in the coastal region. Red tides is a phenomenon when there is a change in the salinity and nitrogen level of the water which causes a proliferation of the small microscopic creatures called dinoflagellates. As a result of this population explosion and the ecological imbalance that results, many fished dies. In addition, these dinoflagellates are also eaten by the larger sea creatures, in particular the shell fishes and when caught and eaten by man, paralytic shell fish poisoning occurs.
The toxin implicated is called saxitoxin. This causes a nerve poisoning and the poor victims can die from being unable to breathe ( respiratory failure ). Imagine dying after a sumptuous plate of chilly crab!! Saxitoxin has a very interesting history. It was developed and used by Russia and USA during the cold war as a chemical weapon. It was actually used to assassinate a Russian defector living in Amercia using something very “james bondish”, a poison umbrella !!. This poison umbrella contained a syringe at the tip which injected the victim with a large dose of poison. All that poor Russian defector felt was a sharp poke in a crowded street. He never knew what hit him !!
The next time you buy cheap tuna, bonito and mackerel think again. Such fishes when left out in the sun becomes stale and will contain high amounts of a chemical called Saurine. Saurine in a chemical resembling histamine and histamine causes an allergic reaction in our body such as itchy rashes, running nose and asthma. Perhaps that is why some of our friends tell us that they are allergic to sea food, but strangely not all the time.
Other than these dangerous fishes, there are also what we call venomous fishes. These are fishes that contain spikes on their body which can be poisonous when in contact with the human skin. One example is the stonefish which lies very still, a stony “silence” that can be easily mistaken for a stone. They are then stepped upon by a human not clever enough to wear booties or sandals on the beach and an excruciating pain results. Sea urchins, the spiny and often menacing looking creatures found amongst coral beds are harmless apart from the potential of embedding their broken spines in your skin and causing an infection later on. The first aid measure to such an excruciating pain ranges from urinating on it to dipping the affected limb in warm water. The warm water relieves the pain until proper medical care can be given. (see below).
Another venomous marine animal is the sea snake. It is one of the most poisonous animal on earth, it’s venom is 10 times that of the King Cobra. Yet it is less harmful when confronted. This is because it has relatively short fangs and it is also more reluctant to inject it’s venom even after the fangs have penetrated the skin. Nature has made use of these fearsome sea snake and some harmless sea snakes have done a “pirated version” by looking like their more poisonous cousins. But I would suggest that unless you are wearing a thick wet suit / gloves not to try to make that distinction!
Jelly Fishes are commonly found in our water. Numerous species abounds. The most dangerous being the Physalia/utriculus (Blue bottle or Portuguese Man o’ war) and the Cubozoan (box jelly fish). Other then being painful, the sting can also cause vomiting and nauseas. The Naval divers diving off Sembawang used to bring a large container of vinegar with them whenever Jelly fish abounds and as a doctor in the Navy, I used to see many such cases. Most are mild pain and leaves no scar. However, in victims that are very sensitive or if a large body area is extensively stung, shock and an acute allergic ( anaphylaxis ) can occur.
The blue ringed octopus has also been sighted in our water before but is more commonly found further a field in the southern hemisphere. The size of a tennis ball, the bite from the blue ringed octopus is dangerous because it causes a respiratory failure and shuts down our ability to breathe.
The last and certainly not the least dangerous of marine animals is the shark. Other then the occasional shark attack most shark are just doing their job cleaning up their ocean that you happen to be floating in. Though it does have a fearsome reputation, only a few species have been known to attack man ( e.g. The Great Whie , Tiger shark, Hammerhead, White tips).That said, more sharks today are killed by us “sharks’ fins eating chinamen” then there are human fatalities from their bites.
There are other fishes that can also cause trauma injury either directly or indirectly. In my practice, I have seen a diver with decompression sickness after a rapid ascent after being hit on the head by a trigger fish and grouper because of their sheer size and temperament has also been known to give a nasty bite.
Basic First Aid – things to do on the spot!
There are some things that one can do in the open sea when dealing with bites, stings from a dangerous marine animals. The basic principle of first aid still applies. Remove from harm, ensure airway, breathing and circulation. Secondary drowning is also an important factor to consider as the panic swimmer may have aspirated sea water in a panic state after struggling with the marine animal.
The use of warm water or vinegar and in the worse case scenario ( when you don’t have either ) urine is known to relieve the pain of the stings from jelly fish and stone fishes. It works by neutralizing the poison that has been injected into the skin. Sometimes part of the sting may be left behind so it is always good to have a doctor look at it and if need be, an X-ray done.
Lie the patient still and arrange for immediate evacuation to a hospital whenever symptoms such as breathlessness, numbness, weakness or any symptoms other then pain is present as toxins can affect the nervous system and paralyse a person or cause a massive allergic reaction.
In terms of prevention and safety, always wear booties or foot gear when beach combing. In areas where there are sea snakes, e.g. near costal swampy area (many has been spotted in the southern coastal part of Singapore), it is good to wear a wet suit.
In conclusion, the sea is full of mysterious creatures, of which only a few of the more well known dangerous ones are mentioned here. But mostly, they are created for our enjoyment and pleasure ……. as long as we know their limits.
This article is contributed by :
LTC N/S A/Prof (DR ) Michael Ong has many years of experience in the Navy treating divers and now runs 2 recompression chamber facilities in Singapore for divers and for delivering hyperbaric oxygen therapy for patient with large/poorly healing wounds (such as diabetics ).
