How to vacation safely: Be cautious of ocean dwellers

Many people take advantage of the warm-weather season to plan vacations to tropical destinations. At Caribbean, South American or Pacific locales, part of the vacation adventure is exploring marine life by snorkeling or scuba diving.

Tropical marine life residing in open water or in reef communities can be some of the most beautiful creatures one ever encounters. The vivid colors and intricate camouflage displays are awe-inspiring. However, when entering the water, it is important to remember that marine creatures can be dangerous, protecting themselves with sharp barbs, poisons and teeth. In many cases, such creatures are docile. However, when provoked or if they feel their territory is threatened, they may defend themselves.

An experienced diver or tour guide will be able to inform vacationers about marine life they may encounter. Here is a listing of some common species you may find that can be dangerous.

Coral: Coral can be sharp and cause cuts or scrapes. It should not be walked upon without foot protection. There are also stinging coral varieties. These are actually marine organisms that have a hard coral-like skeleton. They vary in form from large upright sheets and blades to branching, finger-like "antlers" with a yellow-green to brown color.

Sea anemones and sea cucumbers: These are generally harmless to divers, but some anemones do have a painful sting. Sea cucumbers are one of the safest marine animals to touch, but can shoot a substance designed to blind, so caution should be used. Hands should also be washed after touching to make sure the toxin doesn't make its way into the eyes.

Lionfish: The lionfish is found in the reefs and coastal waters of the Pacific and Indian Oceans. They are recognizable by their brown and white stripes and large dorsal spines and wide-spreading pectoral fins. Poisonous barbs hidden beneath the impressive spines contain a neurotoxin that can paralyze muscles. A sting is rarely fatal to humans, but can be very painful.

Jellyfish: The are many varieties of jellyfish and their stings vary in severity. In some regions, box jellyfish are responsible for killing more people each year than sharks and crocodiles. Free-floating organisms, jellyfish frequent the beaches and coastal regions that many vacationers find attractive. Most tentacle stings occur from people bumping into them because they are relatively invisible in the water.

Stingrays: Stingrays can be found in most temperate and tropical waters of the world. They prefer to bury underneath sand and soil along the ocean floor. Most injuries from their poisonous tail barbs occur from people inadvertently stepping on the stingray or being struck by a flailing tail. Fear of stingrays may have been elevated by the accidental death of popular wildlife enthusiast Steve Irwin, who was killed by a stingray strike to the chest. However, stingrays are largely docile and death from a sting is rare.

Blue-ringed octopus: This is a small species of octopus that is normally yellowish-brown in color. When provoked it displays its namesake blue rings prominently. This octopus resides in small caverns and crevices, so it is wise never to stick your hands into these areas. The octopus can bite, but most people do not notice any pain from the bite. They realize something is wrong after numbness of the mouth occurs, followed by paralysis. The toxin can cause fatal respiratory failure.

Barracudas: These are bold, inquisitive and fearsome fish that can be dangerous to humans. They are found in tropical and temperate water and are attracted to shiny items that resemble the fish they feed upon. There have been instances of barracudas attacking swimmers with their sharp teeth.

Grouper: There are large species of grouper called Nassau grouper that inhabit the Gulf of Mexico and the Caribbean. Some divers have been "bitten" by overly friendly Nassau groupers that are used to human interaction in popular dive feeding sites. These fish can grow to 800 pounds and cause loss of skin in these unintentional bites. Other marine life accustomed to hand feeding may also approach divers and swimmers looking for a free handout, such as moray eels. It's best not to hand feed fish.

Sharks: These awe-inspiring sea creatures also elicit fear from many people. While most sharks are inclined to avoid humans, some inquisitive varieties or aggressive ones are known for biting them, but usually only when provoked or if the person is mistaken for prey. To a shark, a surfer on a surfboard slightly resembles a seal or sea lion, or a diver in a black wetsuit can look like other prey. The Great White, the Tiger, the Bull, and the Oceanic White Tip sharks are the most notorious for biting humans. Usually sharks issue a test bite to see what the "prey" is. Unfortunately due to the size of sharks and the number of teeth they have, a test bite could be quite damaging or fatal to a human. Keep in mind these tips:

+ Do not tease or entice sharks.

+ If you cut or injure yourself … get out of the water. Sharks can smell blood from over a mile away.

+ Watch other fish and turtles in the area for erratic behavior that may indicate a shark is nearby.

+ Do not swim in waters that have been deemed dangerous or are murky. If you feel something brush up against you while diving or swimming, get out of the water and make sure that you have not been bitten. Many shark attack victims have stated there is an absence of pain when bitten.