Blue Ringed Octopus

With a beak that can penetrate a wet-suit, they are one little cute creature to definitely look at BUT Don't touch. The blue-ringed octopus is the size of a golf ball but its poison is powerful enough to kill an adult human in minutes. There's no known antidote. Residing in rock pools and coral, the blue ring octopus' rings will "glow" an electric blue when provoked or is on the defense. This is when it is most dangerous, especially to children, as it looks very pretty and harmless.

sea dangerous animal 2

sea dangerous animal 2
Sharks
I'm certainly not an expert on poisonous marine animals, but you are in luck, as we do have a copy of a book on board the MALCOLM BALDRIGE that's entitled "Dangerous Australians" published in 1985 by Bay Books in Sydney, Australia. This book describes the sea wasp and Portuguese man-o-war that interest you, in addition to about 3 or 4 dozen other deadly animals that inhabit the land and sea surrounding Australia, including crocodiles and the great white shark.
We are very interested in these deadly animals, and we want to know about their distribution around northern Australia, because we are just about ready to make our transit from Male, Maldives to Darwin, Australia. The coastal sea inside the barrier reef around Darwin is home to the sea wasp, the Portuguese man-o-war, the blue-ringed octopus, and some pretty nasty salt- water crocodiles. Because all of these marine animals are extremely deadly, we want to avoid any contact with them, which will probably mean absolutely no swimming at the beaches in Darwin while we are there.

I. The sea wasp, or the box jellyfish ( Latin name Chironex fleckeri Southcott) is one of the most deadly stinging animals in the sea. The sea wasp has a large transparent body shaped like a box or a bell, that can be as large as a bucket, and can weigh as much as 2 kilograms. A cluster of 16 long (up to 3 meters in length) semi-transparent, extendable tentacles stream out from under the bell of the box jellyfish. Millions of stinging capsules cover each of the 16 long tentacles. The stinging capsules discharge lethal poison through a penetrating thread into the skin of any creature that touches them.

The sea wasp is found in coastal waters, creeks, and rivers in Australia north from about 22-degrees south latitude. The box jellyfish ranges from the Queensland coast on the eastern coast of Australia into the Northern Territory, and around the northern coast of Western Australia. The sea wasp is most prevalent during the Austral summer months from November to mid- March.


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 to humans are:
Great white
Tiger shark
Bull shark
Oceanic White tip
Gray sharks (territorial?)
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
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. Read: Jean-Philippe’s bad encounter with a moray eel.

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.


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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 piece 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.

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 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.

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.

Surgeonfish

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.


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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 is found in shallow topical water and in tide pools. 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

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.

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.

Note: During our expedition, we feed on sea urchins. We have researched the species which could be potentially poisonous and places with high poising cases, but haven’t found much information on the subject. If there are any specialists reading this, we would love to receive more information.

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.


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Jellyfish and other venomous invertebrate
There are 9000 species of invertebrates using nematocysts (stinging capsules) to immobilize preys or as a defense.

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.

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 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.
The sea wasp uses its deadly venom to catch prey, which usually consists of prawns. However, when the box jellyfish moves into the coastal areas, rivers, and creeks, particularly during the wet Austral summer season, the sea wasp becomes a deadly menace to swimmers and fishermen in the area. On clear, calm days, the semi-transparent sea wasps can usually be seen and avoided. However, during the wet season, the coastal waterways are often flooded, muddy, and turbid, and the sea wasps are difficult to see until it is too late.

The sea wasp is the cause of numerous deaths to swimmers and bathers along the north Queensland coast of Australia, and because of the potent poison injected by the sea wasp, most children who have been stung by the sea wasp have died within minutes of being stung. The sting of the box jellyfish causes an excruciating pain that increases quickly. Where the tentacles have contacted the skin, large brown or purple lines and welts appear quickly, causing the victim to appear as if he/she has been whipped. The poison injected by the sea wasp causes death by shock to the heart, complete circulatory failure, and respiratory paralysis. If the severe symptoms are not treated quickly, death can occur in minutes, even to an adult. The venom also attacks the victim's red blood cells and severely damages the skin where the poisonous capsules have penetrated the skin. An antivenom for the sting of the sea wasp has been developed, but it must be administered relatively quickly. Because the venom from the sea wasp seriously affects the victim's breathing, it may be necessary to perform continuous CPR to keep a victim alive until professional medical assistance can be obtained.

There are two other cousins to the deadly sea wasp or box jellyfish that are somtimes mistaken for the sea wasp. These are the Carybdea alata Reynaud and the Chiropsalmus quadrigatus Haeckel. Both of these marine animals are also know as sea wasps, but they are not as poisonous or as deadly as the box jellyfish or Sea Wasp (Chironex fleckeri Southcott). As you have learned from this description, we would just as soon not see any sea wasps or box jellyfish in the wild near Darwin. I'm perfectly satisfied seeing these types of marine animals swimming in an aquarium, behind a protective glass barrier.


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.

sea dangerous animal

sea dangerous animal

Sharks

sea dangerous animal Many kinds of sharks live in the warm waters around Australia, like the Whale shark, the Basking shark, the Oceanic White-Tip shark, Dusky shark, Leopard shark and the Hammer shark.. However the largest and most scary, the Great White, is also the most common shark in Australian waters. The smallest shark is the Dwarf shark, and the largest is the Whale shark. As dangerous as they can be, most sharks will not attack humans unless bothered, and actually, sharks themselves don’t have an easy time of it. Dolphins attack sharks in groups to protect their young. The shark's biggest enemy is humans who attack sharks for food, sports and to protect beaches. Sharks appear to be smooth, but up close they have sharp points that are tough. A sharks' body is also streamlined so they can move quickly and easily through the water. Sharks eat other sharks, seals, fish, baby dolphins, birds and sometimes humans…mostly because they mistake them for seals.

The Sea Wasp sea dangerous animal

The Sea Wasp or the box jellyfish is one of the most deadly stinging animals in the sea. The sea wasp has a large transparent body shaped like a box or a bell, that can be as large as a bucket, and can weigh as much as five pounds. A cluster of 16 long semi-transparent tentacles stream out from under the bell of the box jellyfish. Millions of stinging capsules cover each of the tentacles. The stinging capsules discharge lethal poison into the skin of any creature that touches them. Children who have been stung by the sea wasp have died within minutes of being stung

The Portuguese Man-Of War is another stinging jellyfish, and although it is much more widespread and common than the box jellyfish or sea wasp, it is not as deadly as the sea wasp. The Portuguese man-o-war is commonly called the blue-bottle in Australia. Actually, the Portuguese man-o-war is not a single marine animal, but consists of a large colony of smaller marine organisms. The blue-bottle gets its name from the body, which really is a large, gas- filled float. The float has a crest, that is used much as a sail to propel the colony across the water when the wind blows. Although the sting from the Portuguese man-o-war is not deadly to humans, a person who comes into contact with a Portuguese man-o-war or blue-bottle will still experience a sharp severesea dangerous animal pain.

The Blue-Ringed Octopus sea dangerous animal

The Blue-Ringed Octopus is another one of the smaller, but more deadly marine animals that inhabit the coastal waters around Australia. The blue-ringed octopus is normally light in color, with dark brown bands over its eight arms and body, with blue circles superimposed on these dark brown bands. When the octopus is disturbed or taken out of the water, the colors darken and the rings turn a brilliant electric-blue color, and it is this color change that gives the animal its name. The blue-ringed octopus secretes a very deadly poison, either by biting with its parrot-like beak, or by squirting the poison into the water surrounding it. The direct bite from the blue-ringed octopus is usually painless, but the deadly effects of the poison will be noticed immediately. The poison apparently interferes with the body's nervous system. The victim will immediately experience numbness of the mouth and tongue, blurring of vision, loss of touch, difficulty with speech and swallowing, and paralysis of the legs and nausea. If the victim does not receive medical treatment immediately, full paralysis may occur within minutes, followed by unconsciousness and death due to heart failure and lack of oxygen. There is no antivenom for the poison from a blue-ringed octopus. It is usually necessary to perform continuous CPR on a victim until the effects of the venom have subsided. This may take several hours, but it may mean the difference between life or death for the victim.