Deadly Oceans: In Search Of The Deadliest Sea Creatures

Handle with care

While the vast majority of catfish are harmless to humans, a few species are known to present some risk. Many catfish species have “stings” (actually non-venomous in most cases) embedded behind their fins; thus precautions must be taken when handling them.

Ambush predators

Crocodiles are top predators in their own environment. They are specialist hunters with the ability to strike at extreme speed and are very fast over short distances, despite their size and ungainly appearance out of water. They are ambush predators which blend into their environment, wait for prey to pass close by, and then strike.

READ MORE: Welcome to croc country

Impressive hunters

We tend to think of dolphins as friendly, happy creatures which are more than willing to interact with humans. Some of this is true and wild dolphins will regularly come and interact with divers and boats. They are very intelligent creatures and live complex social lives, but they also have to eat, and are amongst the most impressive hunters in the ocean.

Hunting Nemo

Many people refer to sea anemones as ‘flowers of the sea’, largely as a result of their superficial resemblance to terrestrial plant blooms. They are, however, carnivorous animals, and while they may come in many different sizes and beautiful colours, they have evolved various strategies for catching their prey.

Voracious predators

The lionfish are a family of a dozen venomous fish species which is native of the Indo-Pacific region. While they are voracious predators, their venomous spines are only used for defence. A sting from a lionfish, however, can be particularly painful and difficult to treat.

Scariest of them all

Of all the shark species around the world, the most feared is the great white shark. It is the largest of the predatory sharks and it can move incredibly quickly over short distances to ambush its prey by striking from below, or from out of bright sunlight. Such is the power of these attacks that they often result in the shark breaching fully out of the water in pursuit of prey, which often includes seals and sea lions.

Fast and furious

Although frogfish pose no threat to humans, they are included in this book due to their incredible hunting ability. They have the fastest strike of any animal. The strike action includes the ability to open their mouths and increase the volume hugely, so that it sucks in both the prey and surrounding water. The attack can be a quick as 6 milliseconds, and frogfish can expand their stomachs to hold prey up to twice its size.

Surprise encounters

Divers regularly encounter seals and sea lions, and the young in particular are very curious and like to buzz past to get a view of any interlopers in their territory. Once they have gained confidence, they will swim around divers and even hold onto fins and gently bite down on neoprene suits. It is very rare indeed for humans to be harmed by pinnipeds, although there have been a handful of isolated, and in one case fatal, attacks by large leopard seals, and also some painful, but not serious, bites to divers from smaller species.

Don’t provoke

Across the world dolphins are well known for their benevolent interactions with humans. Only one dolphin has been known to attack and kill a person, and that was after considerable provocation. There are, however, numerous occasions where solo bottlenose dolphins have injured people who’ve gone out to swim with them.

Under the hammer

Hammerhead sharks are generally considered to be a small species, although the great gammerhead can grow to lengths in excess of 5m (16ft) and while few attacks have been recorded, surfers tend to view them as potentially dangerous. They are pelagic for much of the time but can also come close to shore in the shallows. They are known to be prone to sunburn!

Elegant hunter

The silky shark is possibly the most elegant of all the shark species, and while it is not particularly large, it can grow to a length of 3.5m (11.5 ft). It is known for its particularly acute hearing and, when hunting in packs, is usually highly effective at locating and catching its favourite prey, tuna. Hunting tuna, however, does leave them vulnerable to being caught as by-catch by humans.

Disconcerting dive

Sea snakes are only dangerous to humans when provoked or accidentally disturbed and unable to swim away, which would be their natural instinct when faced with such a large intruder. However, they can be disconcerting to dive with, as on their way to the surface to breathe, they can sometimes pass right by your mask.

Toxic slugs

Nudibranchs, or sea slugs, have had to develop ways to protect themselves from predation. One of nature’s most effective ways of doing this is to become toxic. Nudibranchs have adapted this in a specialised way, by recycling the toxins from the food that they eat. Some species dine on toxic sponges and can adapt these compounds and store them in their skin, releasing them from their glands if disturbed.

Beautiful warning

Nudibranchs try to warn off predators by using bright colours to indicate their poisonous nature. Because of their beautiful colouration, and their variations in size and shape, these molluscs have developed a cult-like following among many scuba divers. There are currently more than 2000 known species, but it is thought there may be as many as twice this number, with new species being discovered regularly.