TROPICAL DANGERS
ON and UNDER WATER
Animals that can kill or maim
Sharks
Sharks are the most feared animal in the sea. Usually, shark attacks cannot be avoided and are considered accidents. You, as a survivor, should take every precaution to avoid any contact with sharks. There are many shark species, but in general, dangerous sharks have wide mouths and visible teeth, while relatively harmless ones have small mouths on the underside of their heads. However, any shark can inflict painful and often fatal injuries, either through bites or through abrasions from their rough skin.
There are about 350 species of sharks, only 30 species could potentially be dangerous to humans and only 12 are reported potentially aggressive and dangerous. To put things in perspective 300 times more drowning are reported than fatal shark attacks.
Among the most dangerous t
o humans are:
Great white
Tiger shark Bull shark
Oceanic White tip
Gray sharks
Mako
Only a few species consider people as prey. They usually attack mistaking humans for marine animals on which they feed (mammals or sea turtles).
Most of the other sharks attack are provoked (feeding, spearfishing, bleeding, etc.)
Sharks don’t have many predators. They might shy away if charged by a person, or be wary of someone facing them with a stick or long object. In other situations, some species of sharks have been known to attack at great speed without any warning.
Shark’s weak points are their gills (striking them there with the handle of a knife or a snorkel could fend them off)
Barracuda
Large carnivorous fish (up to 7 feet). Can be found in large schools.
Doesn’t feed on humans, but have reported to accidentally attack people wearing brightly colored things (watch, necklace, dive lights (especially at night), etc.
Depending on geographical locations, some species seem to show more or less aggressiveness.
It is said that when Barracuda get agitated the spots on their backs get darker.
Crocodiles, Alligators and Caimans
Very aggressive,fast and powerful. They are territorial and highly dangerous to humans. Feeding usually happens in the evening. Large crocodiles have been reported to attack canoes. Salt water crocodiles living in river estuaries are known to be generally bigger and more aggressive toward people. They can sometimes also be found up rivers in fresh water. They can also attack on land and run extremely fast.
In case of confrontation, humans don’t have much chance but poking the eyes (with a stick for example) has been reported as the thing to try.
Sea Lions
Sea lions are usually playful, however they can be territorial and dangerous especially during the mating seasons. Accidents among divers are reported much more frequently than with sharks. Advice: get out of water if sea lions show territorial behavior (barking), don’t swim with large males, don’t approach sea lions during the mating season.
Moray Eels
Scary looking, they can reach 6 to 8 feet. Their teeth are razor sharp and their bites can lead to profuse bleeding and often get infected. Usually moray eels aren’t aggressive toward divers. They even sometimes get fed. But sometimes they can be territorial or become aggressive and go after speared fish. Moray eels can be toxic to eat (the gymnothorax toxin resemble the ciguatera poisoning)
Octopus and squids
Octopus can grow quite big and do not usually attack people but there have been a few recorded incidents with divers. Mainly playing or defending themselves. Octopus have a beak and can inject a mild venom (* the small blue ring octopus venom can be deadly).
Large squids have been reported to be extremely aggressive and injure fisherman. Giant Squids live deep in the ocean (few thousand feet deep) and are believed to have attacked large boats. Large sperm whale feed on them and sometimes get giant scars from their encounters.
Marlin, Sailfish, Swordfish and Sawfish
A few accidents have been reported by schools of fish stalking boats and impaling people (this is very rare). Most accidents happen while game fishing with the fish fighting for his freedom. Avoid using flashlights at nights in areas of schooling.
Venomous Fish (stinging)
Stonefish
Most venomous fish known. Up to 12 inches long, perfectly camouflaged, it looks very much like a stone. Only dangerous if stepped on or caught. The dorsal spines can pierce through a shoe. The pain is excruciating and can last for months with tremendous swelling and death of tissues. Amputation might be required. If not treated, stonefish stings can often be deadly. Stonefish (Synanceja species) are in the Pacific and Indian oceans.
Most venomous fish known. Up to 12 inches long, perfectly camouflaged, it looks very much like a stone. Only dangerous if stepped on or caught. The dorsal spines can pierce through a shoe. The pain is excruciating and can last for months with tremendous swelling and death of tissues. Amputation might be required. If not treated, stonefish stings can often be deadly. Stonefish (Synanceja species) are in the Pacific and Indian oceans.
First Aid:
Remove pieces of spines, encouraging bleeding might remove some venom, wash with water. Rest and elevate. If possible immerse wound in hot water (45 C or 113 F) for 30-90 minutes or until pain decreases. Then rest, elevate and dress with something clean.
On Site Treatment:
Local cleaning of wound and removal of broken spines should be treated with antibiotics (neomycin or bacitracin).
Local anesthetics (e.g 5-10 mg Lignocaine 2% without epinephrine injected through the punctured wound. Bupivacaine is longer lasting. Emetine HCl 0.5-1.0 ml at a concentration of 50mg/n\ml injected in wound site.
Treatment:
If given early: local injection into the site with hyoshine butylbromide (Buscopan), or emetine hydrochloride.
Stonefish antivenom
Stingrays
There are many species of stingrays among which some can also be fatal. The pain delivered is excruciating and can last for months accompanied with significant swelling. Stingrays aren’t aggressive. They lay on or near the bottom, submerged in the sand and only sting people stepping on them (or fisherman removing them from nets). Their sting can cause very deep lacerations and profuse bleeding.
To avoid stepping on stingrays, shuffle feet in shallow water while going swimming. If given the choice the ray will flee.
Scorpionfish
There are 330 species of scorpionfish. Like stonefish, many looks like rocks. They have venomous spines from which they inject venom. Although not as dangerous as stonefish, or stingrays, they should be treated the same way. The most famous are the lionfish, zebra fish (Scorpaenidae species) or turkeyfish (also called butterfly cod), 30cm long, brightly colored red or brown fish. Beautiful (praised in aquariums). They are usually found in shallow water. The devil fish looks much more like a large stone. The red rock cod looks like a stone often with a red belly. Poisonous scorpion fish or zebra fish are mostly around reefs in the tropical Indian and Pacific oceans and occasionally in the Mediterranean and Aegean seas. They average 30 to 75 centimeters in length. Their coloration is highly variable, from reddish brown to almost purple or brownish yellow. They have long, wavy fins and spines and their sting is intensively painful. Less poisonous relatives live in the Atlantic Ocean.
Catfish
There are 330 species of scorpionfish. Like stonefish, many looks like rocks. They have venomous spines from which they inject venom. Although not as dangerous as stonefish, or stingrays, they should be treated the same way. The most famous are the lionfish, zebra fish (Scorpaenidae species) or turkeyfish (also called butterfly cod), 30cm long, brightly colored red or brown fish. Beautiful (praised in aquariums). They are usually found in shallow water. The devil fish looks much more like a large stone. The red rock cod looks like a stone often with a red belly. Poisonous scorpion fish or zebra fish are mostly around reefs in the tropical Indian and Pacific oceans and occasionally in the Mediterranean and Aegean seas. They average 30 to 75 centimeters in length. Their coloration is highly variable, from reddish brown to almost purple or brownish yellow. They have long, wavy fins and spines and their sting is intensively painful. Less poisonous relatives live in the Atlantic Ocean.
Catfish
Catfish also have spines (3) attached to their dorsal and two lateral fins. They can be dangerous to handle, but catfish do not attack.
Surgeon fish or Tang
Beautiful tropical fish. There are many species all characterized by a scalpel like spine protruding from the junction of their body and tail. (They could be venomous). Injuries only happen when handling fish. Surgeon fish can also cause ciguaterra poisoning if eaten. Tang or surgeonfish (Acanthuridae species) average 20 to 25 centimeters in length and often are beautifully colored. They are called surgeonfish because of the scalpel like spines located in the tail. The wounds inflicted by these spines can bring about death through infection, envenomation, and loss of blood.
Beautiful tropical fish. There are many species all characterized by a scalpel like spine protruding from the junction of their body and tail. (They could be venomous). Injuries only happen when handling fish. Surgeon fish can also cause ciguaterra poisoning if eaten. Tang or surgeonfish (Acanthuridae species) average 20 to 25 centimeters in length and often are beautifully colored. They are called surgeonfish because of the scalpel like spines located in the tail. The wounds inflicted by these spines can bring about death through infection, envenomation, and loss of blood.
Rabbitfish
Rabbitfish or spinefoot (Siganidae species) occur mainly on coral reefs in the Indian and Pacific oceans. They have very sharp, possibly venomous spines in their fins. Handle them with care, if at all. This fish, like many others of the dangerous fish in this section, is considered edible by native peoples where the fish are found, but deaths occur from careless handling. Seek other nonpoisonous fish to eat if at all possible.
Toadfish
Toadfish (Batrachoididae species) occur in tropical waters off the Gulf Coast of the United States and along both coasts of Central and South America. These dully colored fish average 18 to 25 centimeters in length. They typically bury themselves in the sand to await fish and other prey. They have sharp, very toxic spines along their backs.
Weever Fish
Weever fish (Trachinidae species) average 30 centimeters long. They are hard to see as they lie buried in the sand off the coasts of Europe, Africa, and the Mediterranean. Their color is usually a dull brown. They have venomous spines on the back and gills.
Toadfish
Toadfish (Batrachoididae species) occur in tropical waters off the Gulf Coast of the United States and along both coasts of Central and South America. These dully colored fish average 18 to 25 centimeters in length. They typically bury themselves in the sand to await fish and other prey. They have sharp, very toxic spines along their backs.
Weever Fish
Weever fish (Trachinidae species) average 30 centimeters long. They are hard to see as they lie buried in the sand off the coasts of Europe, Africa, and the Mediterranean. Their color is usually a dull brown. They have venomous spines on the back and gills.
Other animals with the ability to inject venom
Blue-Ringed Octopus
Very small in size (2 to 20 cm, 10 to 100g) the beautiful blue ringed octopus (Hapalochlaena lunulata) is found in shallow topical water and in tide pools, fortunately, it is restricted to the Great Barrier Reef of Australia. It is easily recognized by its grayish white overall color and iridescent blue rings. The rings can turn to a bright blue to show the change of mood of the octopus.
The bite might be painless, but this octopus injects a neuromuscular paralyzing venom. The venom contains some maculotoxin, a poison more violent than any found on land animals. The nerve conduction is blocked and neuromuscular paralysis is followed by death. The victim might be saved if artificial respiration starts before marked cyanosis and hypotention develops.
Cone Shell
The subtropical and tropical cone shells (Conidae species) have a venomous harpoon like barb. All are cone-shaped and have a fine netlike pattern on the shell. A membrane may possibly obscure this coloration. There are some very poisonous cone shells, even some lethal ones in the Indian and Pacific oceans. Avoid any shell shaped like an ice cream cone.
Cone Shell
The subtropical and tropical cone shells (Conidae species) have a venomous harpoon like barb. All are cone-shaped and have a fine netlike pattern on the shell. A membrane may possibly obscure this coloration. There are some very poisonous cone shells, even some lethal ones in the Indian and Pacific oceans. Avoid any shell shaped like an ice cream cone.
400 species of cone shells can inject venom, a few species only are believe to be dangerous. Effects may vary from being painless to excruciating pain. Salt water seems to make it worse. Paralysis including respiratory failure may occur.
Auger Shell
The auger shell or terebra (Terebridae species) are much longer and thinner than the cone shells, but can be nearly as deadly as the cone shells. They are found in temperate and tropical seas. Those in the Indian and Pacific oceans have a more toxic venom in their stinging barb. Do not eat these snails, as their flesh may be poisonous.
Crown of Thorns
Starfish up to 60cm in diameter and with 13 to 16 arms covered with sharp spines. It is usually found in deeper water than other starfish. Effects: severe pain for a few hours. Possible bleeding. Possible inflammation, extending to swollen lymph glands areas. Symptoms may continue for weeks or months especially if spines are left in the wound.
Sea Snakes
There are 87 species of sea snakes classified in two categories. The bottom feeders (like the striped banded sea snakes) and the pelagic (like the yellow-bellied sea snake). Sea snake live in all tropical waters except the Atlantic. They can be recognized by their flat tail used for swimming. Their poison is 20 times more powerful than the one of the cobra, but they inject much less if they inject any at all. Some have a very small mouth and are unable to bite large prey. First Aid: Immobilization and pressure bandaging of affected limbs; CPR (cardiovascular failure is the first cause of death, renal problems is the second one); and antivenom to be administered in a medical facility.
Sea Urchins
Spines might contain some venom and bring infections. Very few fatal cases were reported (usually from respiratory problems), but most cases bring mild to severe pain for few hours to infections that could last for months, especially is pieces of spines are left in the wound. Removal of spines should be done surgically or with extreme caution not to break them more into the wound.
Sea Urchin roe is a delicacy in many countries but poisoning may occur.
Sponges
Various type of sponges can produce irritations and pain for long periods. In doubt it is best not to touch any sponge (even dead ones washed out on shores).
Sea Worms
There are many species of tropical sea worms found under rocks and in coral. These can produce painful and itchy rashes lasting for hours. Antihistamine or steroid application might help.
Sea Lice
Jellyfish and other venomous invertebrate
There are 9000 species of invertebrates using nematocysts (stinging capsules) to immobilize preys or as a defense. (First Aid listed below)
Jellyfish-related deaths are rare, but the sting they inflict is extremely painful. Avoid the long tentacles of any jellyfish, even those washed up on the beach and apparently dead.
Chironex, also known as Boxfish or Deadly sea wasp
Jellyfish-related deaths are rare, but the sting they inflict is extremely painful. Avoid the long tentacles of any jellyfish, even those washed up on the beach and apparently dead.
Chironex, also known as Boxfish or Deadly sea wasp
Considered to be the most venomous marine creature. Death can occur with minimal contacts. Chironex are found in the warm waters of Pacific and Indian oceans. All reported deaths (70) have occurred in northern Australia between November and April. When death does not occur, the pain is excruciating and often stings leave significant scars.
Portuguese Man Of War (Physalia)
Fatalities have been reported, but usually victims survive after suffering from excruciating pain. The Portuguese man-of-war resembles a large pink or purple balloon floating on the sea. It has poisonous tentacles hanging up to 12 meters below its body.
Other Jellyfish
Many other jellyfish species are found. Contact with those may vary from a mild local itch to severe burning with throbbing pain. Some can lead to cardio-respiratory deficiency.
Fire Coral
This animal looks like coral and is often found on coral reefs. It has small invisible tentacles with nematocysts. Locally, effects may vary from minor irritation of the skin to excruciating pain. Nausea and vomiting for a few hours is possible if a large surface of the skin comes in contact with fire coral.
Sea Anemones
Some can produce the same effect as the Portuguese Man of War (physalia)
Stinging Seaweed
The stinging seaweed is an animal that looks like a fern. The color varies between brown and green, but can also be white or purple. Sensation varies from mild stinging to extreme pain. The skin turns red after 30 minutes with itchy pustules that can stay for a week.
Glaucus
It is an invertebrate also called Lizard Nudibranch. Long of 1-3 cm, usually blue on his dorsal surface and white on his ventral surface. It has a characteristic inflated air pocket. This animal feeds on various nematocysts, and the effects of it’s touch varies depending on the nematocyst it consumed.
First Aid for all nematocyst injuries
First Aid
If tentacles of nematocysts are still stuck to the skin, they need to be removed gently. Be careful not to squeeze them as to not discharge more nematocysts.
Local anesthetic spray or ointment may remove some of the pain on minor stings. Tannic acid is believed to work well.
Give cardiovascular and respiratory assistance if needed.
Medical Treatment
The best anesthetic ointments in order of efficiency seem to be: Lignocaine 5%; Ultralan 0.5% and Lignocaine gel. Benadryl cream isn’t as effective. Commercial creams don’t work as long.
Severe itching may occur after a few days. Steroid ointments (i.e. hydrocortisone) could help.
If tentacles of nematocysts are still stuck to the skin, they need to be removed gently. Be careful not to squeeze them as to not discharge more nematocysts.
Local anesthetic spray or ointment may remove some of the pain on minor stings. Tannic acid is believed to work well.
Give cardiovascular and respiratory assistance if needed.
Medical Treatment
The best anesthetic ointments in order of efficiency seem to be: Lignocaine 5%; Ultralan 0.5% and Lignocaine gel. Benadryl cream isn’t as effective. Commercial creams don’t work as long.
Severe itching may occur after a few days. Steroid ointments (i.e. hydrocortisone) could help.
Animals and Fish Poisonous to Eat
Survival manuals often mention that the livers of polar bears are toxic due to their high concentrations of vitamin A. For this reason, we mention the chance of death after eating this organ. Another toxic meat is the flesh of the hawksbill turtle. You recognize them by their down-turned bill and yellow polka dots on their neck and front flippers. They weigh more than 275 kilograms and are unlikely to be captured.
Many fish living in reefs near shore, or in lagoons and estuaries, are poisonous to eat, though some are only seasonally dangerous. The majority are tropical fish; however, be wary of eating any unidentifiable fish wherever you are. Some predatory fish, such as barracuda and snapper, may become toxic if the fish they feed on in shallow waters are poisonous. The most poisonous types appear to have parrot like beaks and hard shell-like skins with spines and often can inflate their bodies like balloons. However, at certain times of the year, indigenous populations consider the puffer a delicacy.
Blowfish
Blowfish or puffer (Tetraodontidae species) are more tolerant of cold water. You find them along tropical and temperate coasts worldwide, even in some of the rivers of Southeast Asia and Africa. Stout-bodied and round, many of these fish have short spines and can inflate themselves into a ball when alarmed or agitated. Their blood, liver, and gonads are so toxic that as little as 28 milligrams (1 ounce) can be fatal. These fish vary in color and size, growing up to 75 centimeters in length.
Triggerfish
The triggerfish (Balistidae species) occur in great variety, mostly in tropical seas. They are deep-bodied and compressed, resembling a seagoing pancake up to 60 centimeters in length, with large and sharp dorsal spines. Avoid them all, as many have poisonous flesh.
Barracuda
Although most people avoid them because of their ferocity, they occasionally eat barracuda (Sphyraena barracuda). They occasionally carry the poison ciguatera in their flesh, making them deadly if consumed.
Many fish living in reefs near shore, or in lagoons and estuaries, are poisonous to eat, though some are only seasonally dangerous. The majority are tropical fish; however, be wary of eating any unidentifiable fish wherever you are. Some predatory fish, such as barracuda and snapper, may become toxic if the fish they feed on in shallow waters are poisonous. The most poisonous types appear to have parrot like beaks and hard shell-like skins with spines and often can inflate their bodies like balloons. However, at certain times of the year, indigenous populations consider the puffer a delicacy.
Blowfish
Blowfish or puffer (Tetraodontidae species) are more tolerant of cold water. You find them along tropical and temperate coasts worldwide, even in some of the rivers of Southeast Asia and Africa. Stout-bodied and round, many of these fish have short spines and can inflate themselves into a ball when alarmed or agitated. Their blood, liver, and gonads are so toxic that as little as 28 milligrams (1 ounce) can be fatal. These fish vary in color and size, growing up to 75 centimeters in length.
Triggerfish
The triggerfish (Balistidae species) occur in great variety, mostly in tropical seas. They are deep-bodied and compressed, resembling a seagoing pancake up to 60 centimeters in length, with large and sharp dorsal spines. Avoid them all, as many have poisonous flesh.
Barracuda
Although most people avoid them because of their ferocity, they occasionally eat barracuda (Sphyraena barracuda). They occasionally carry the poison ciguatera in their flesh, making them deadly if consumed.
