The ocean reefs are teaming with life and without question are most threatened by humans. The creatures which inhabit these areas are amazing, beautiful and sometimes deadly. People should be aware of them and treat them with respect. A diving experience on a reef is an experience beyond words but remember you are a visitor to a strange land there to look but not touch.
The blue ringed octopus is a small golf ball animal whose bite can deliver tetrontoxin a neurotixin which can cause death and for which there is no known antidote. It's blue rings become visible only when the octopus is agitated. It's beak is capable of going through a wet suit and while it's painless paralysis and respiratory failure follow.
Sea snakes have scales and flattened tails. These animals are gentle and shy but all are highly venomous. They may approach you out of curiosity but will continue on with their business if left alone. Often when they do bite they won't use their venom for which there are antidotes. They breath air and have to surface. It's best to wear shoes with good soles when walking in these areas as snakes will often lie in the sand. An unsuspecting person may step on one before they know it's there.
Scorpionfish all have venomous spines on their dorsal fins. Except for the colorful Lionfish they blend in well with their environment. They sit within the coral, being gray or brownish, and wait for prey to come along. They are capable of great bursts of speed when the next meal makes an appearance. Stings from these animals have been known to kill, in particular from the Lionfish.
Stonefish are the most venomous fish in the world. True to their name they look like a stone which is how they disguise themselves as they wait for some unsuspecting fish. Their protection against other predators are thirteen sharp spines along their back. These deliver a neurotoxin which can cause paralysis, shock and pain. In rare cases most victims recover completely but deaths have been recorded. Their spines can penetrate rubber soles. So when wading in muddy water, shuffle you feet and be aware of your surroundings.
Cone Shells are beautifully marked but are also capable of delivering a poisonous sting using a harpoon. This weapon can be fired several times and is used to catch it's prey. It can penetrate a wetsuit and deliver neurotoxins which will cause loss of coordination in humans.
Deaths have been reported but they are rare.
Stingrays hide under rocks in shallow waters. They are normally gentle creatures but as in the case of Steve Irwin can cause death by delivering their stings. The sting is purely defensive as they hunt by shuffling through the sea bottom for food. Shuffle your feet when walking in water and they'll avoid coming in contact.
Only a few species of jellyfish are a serious threat to humans. But their tentacles can still deliver a painful sting. Even those severed and washed up on the beach can cause injury, so its best to leave them alone. The Box Jellyfish, the most venomous of the jellies, rarely comes around the reefs but can be found in the northern coastal waters of Australia. Covering the skin is the best protection against these creatures.
Hydroids and Fire Corals, of which the jellyfish is a relative, attach themselves to rocks and look like dead coral with a whitish or yellowish tip. Some crabs will carry these on their shells as a manner of protection against other predators. The sting is usually from brushing up against them and can be avoided by covering the skin. The wound is called by the release of nematocysts, or stinging cells. They can cause severe skin irritation or rashes.
Sharks are in every ocean and you may run into one of the many varieties when diving. Depending upon where you are you may encounter the Blacktip Reef, Caribbean Reef, Grey Reef, Silvertip Reef and Whitetip Reef just to name a few. These are serious predators but most will avoid humans so long as they not provoked. The media has made them into villains and injuries and deaths happen but given the number of human divers and sharks encounters that occur every year incidents are rare. The best approach, as with all predators, is healthy respect.
Moray eels spend most of their time hiding in crevices within the reef. They are waiting for their next meal. But they have sharp teeth and are capable of inflicting a serious bite. Their teeth are designed to tear. They can be aggressive so beware trying to touch one.
The coral reefs need us to protect them and hold them for future generations to enjoy. Their intricate beauty and strength is something we will not be able to replace once lost. As with all wild things give them the respect they deserve and prepared to be awe stricken.
Sources for this article are listed below
www.diving with sharks.com