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The Untouchables: Marine Creatures that are Best Left Alone

Story and photos by Tom Ryan

Have you ever been afraid of some of the animals that you might encounter when you go snorkeling or scuba diving? For most of us the honest answer is 'yes.' It might be comforting to know that a lot of your diving peers have also felt at least some anxiety about marine life at one time or another. A little uneasiness is probably a good thing. It motivates us to educate ourselves about the environment we are entering.
So often our fears about the marine environment focus on creatures like sharks, barracudas, moray eels, and other creatures that dominate the tales of sea lore and television screens around the world. But when divers, snorkelers and swimmers encounter problems with unprovoked marine animals, it is usually not with the big, bad animals that Hollywood and the Discovery Channel love us to fear. In fact, most human injuries from marine creatures are usually the result of people touching, grabbing, handling, harassing, provoking, teasing, taunting or otherwise annoying animals whose defense mechanisms are designed to repel or kill other marine creatures. 
This article is intended to help you avoid these injuries. The truth is that some injuries occur. It is equally true that by using common sense you can easily avoid the vast majority of the injuries that will be discussed here. However, it is also true that if you dive long enough either you or someone you know or dive with will experience some underwater misfortune. Clearly, most of the injuries are not life threatening, but they can be painful enough to take the fun out of a dive. With this in mind, it only makes sense to educate yourself and do what you can to avoid being injured.
While I do mention some basic first aid, this article is not a first-aid primer. Instead, the primary focus is upon helping you avoid a number of easily preventable injuries. 
There are four rather general, nonscientific categories of marine animals that can cause injuries to divers. They are the biters, stingers, pokers and other miscellaneous creatures.

The Biters
If you look at many older diving texts, the animals discussed in the 'dangerous marine creatures' chapter were mostly sharks, barracudas, killer whales, moray eels, sea snakes, bull sea lions, elephant seals and perhaps big groupers. Today, with perhaps the exception of the way we feel right after watching several nights' worth of 'Shark Week' on the Discovery Channel, most of us realize that these high-profile animals rarely cause any problems for divers unless they are baited, handled or harassed in some manner. To my knowledge, even in last summer's incidents in Florida and the Bahamas, no divers were involved.
Any animal that is equipped with teeth will sometimes bite when feeling threatened or provoked, and when competing for food. 
As cute and cuddly as seals and sea lions appear to be, they are wild creatures. During the breeding season, mature males can be highly territorial and will attempt to chase away intruders. Pay heed, they are big and powerful, and have far less tolerance for intruders than some 'Bambiesque' Disney movies might lead you to believe. So don't push them, especially during their mating seasons.
Perhaps the inclusion of octopuses in this section will come as a surprise. However, even when handled gently octopuses have bitten divers. Octopuses are equipped with powerful parrotlike beaks that can penetrate the hard shells of crabs, lobsters and mollusks. And that is not all; when octopuses bite they often inject a toxin that is intended to paralyze their natural prey.

The Stingers
There are a variety of animals that can cause injuries to humans by stinging. The majority of these animals are described in the phylum Cnidaria, a grouping that includes corals, sea anemones, jellies and hydroids (fire 'corals,' Portuguese men-of-war and sea wasps, etc.). While many species have a rather delicate appearance, the tentacles of all cnidarians are equipped with toxin-laden, harpoonlike stinging cells known as nematocysts. Many cnidarians are attached to the sea floor or they are very poor swimmers or 'walkers.' As a result, their toxins need to be powerful and fast-acting because they are their primary means of defense and for capturing prey. In short, the looks of many of the stingers belie their potency. 
Although I do not know of any surveys that have been conducted, I suspect that a variety of fire 'corals' are near the top of the list of 'stingers' that injure divers in tropical settings. Though they are commonly called 'corals,' these cnidarians are actually types of hydroids. But no matter how you refer to them, brushing against one is likely to be an experience one won't soon forget as many species pack a potent wallop that often develops into itching, blistering welts. 
Fire corals occur in a variety of shapes and forms. Some species are flat and branched, and they look like some kind of porcelain sculpture. Some are long and thin; and others occur in tall, curved sheets. Still others encrust sea fans and other corals taking on the shape of the organisms they overtake. Most fire corals have an orange, tan or whitish hue.
Hard corals such as plate corals, staghorn corals and brain corals also sting their prey, and as a result they can be hazardous to divers. Usually it is the infections that result from coral cuts that cause problems. Corals are commonly coated by mucus, and it is the mucus that causes the infections. Often divers do not feel the cuts when they occur, and even back on the surface following a dive the cuts 'don't seem to be a big deal.' Treat even mild abrasions by washing the area and applying an antibacterial ointment.
The good news is that most coral cuts can be avoided by maintaining proper buoyancy control. Avoid resting on, grabbing or kicking corals and you'll avoid injury.
Over the years I have heard many divers swear that they have handled an anemone without getting stung. The truth is that the anemone's stinging cells fired on contact, but in some cases human skin is too thick for the stinging cells to penetrate. Be forewarned, there are plenty of delicate looking species of anemones equipped with stinging cells that easily penetrate human skin, and getting nailed by one of these species can produce a painful injury that results in a festering rash.
As painful as these previously mentioned collection of bottom-dwelling cnidarians can be, at least they are usually easy to see. That is not always the case with jellies, Portuguese men-of-war, sea wasps and the like as these creatures have translucent, or semi-translucent bodies and tentacles. If you see a jelly or jellylike organism in the water, pay attention. Where there is one, there are likely to be many more. The stinging cells are concentrated in tentacles that trail behind the bell, and in some cases the tentacles can be as much as 40 feet (12 m) long.
Common sense is the rule here. If you think there are so many stinging creatures floating by in the water that you are likely to get stung, consider aborting the dive. And when making safety stops, especially in areas where there is a current, I often find it best to face away from the current so that the bare skin of my face is not as exposed to stinging organisms that might drift into me sight unseen. 
In the case of cnidarian stings, clean and treat the affected areas. Applying a topical treatment of meat tenderizer and white vinegar will help to break down many pain-producing toxins. Do not rinse the affected area with fresh water. Doing so can cause unfired nematocysts that are in contact with the skin to fire. After cleaning, apply an antibiotic ointment. It is also a good idea to thoroughly wash wet suits and other dive gear in salt water to rid them of unfired nematocysts, especially in the case of stings by jellies and hydroids. The stinging cells in tentacles that have been separated from the animals have been known to pack a powerful punch as long as 24 hours after the original contact. 
While stings from some cnidarians can prove painful, they are rarely serious. However, some people are known to have severe allergic reactions. 
Although sponges are not cnidarians, contact with several species or even later contact with fins or gloves that touched these sponges, can cause severe itching. The Caribbean sponge known as dread red (also known as touch-me-not) is a classic case in point. The name dread red is given in reference to the color a diver's skin is likely to turn after touching one of these brown-to-maroon sponges underwater. 
Bristle worms are attractive, free-living worms that spend the majority of their lives crawling along reefs and on gorgonians. Most specimens are 3-10 inches (7.5-25 cm) long with body colors that vary from vibrant hues of red, orange and green to drab green or brown. Their bodies are lined with numerous tufts of white bristles. The bristles are venomous and sharp as glass, and can easily penetrate human skin. The bottom line: do not handle even when wearing gloves.

The Pokers
Sea urchins, scorpionfishes, stonefishes, pufferfishes and stingrays make up the majority of the so-called pokers. Of these, clearly it is the sea urchins that cause the most injuries to divers. The sharp spines of these living pincushions penetrate human skin with surprising ease, and the spines readily break off when they puncture skin. The spines have been cleverly crafted by Mother Nature to easily penetrate the skin of animals that pose threats to sea urchins, but the barbed design and brittle nature of the spines make them very difficult to remove. 
In most cases, hot water, the repeated application of antibacterial ointment and time will alleviate any problems. 
Fishes with sharp, and in some cases venomous, dorsal spines such as scorpionfishes, sculpins and stonefishes can cause injuries to divers. Many of these species are masters of camouflage that don't readily flee when approached. It is always wise to check out the sea floor for these camouflage artists before settling onto a sandy spot on the bottom. 
If you spend much time around the diving community, every once in a while you will hear about a beachgoer that got punctured by the knifelike barb of a stingray. In most cases people accidentally step on stingrays that are partially buried in the sand in shallow areas. When stepped on, a ray might respond by jabbing the responsible party with its barb, and they might do the same thing to divers that try to handle them. Dragging your feet or fins in the sand while doing the 'stingray shuffle' is always wise when entering and exiting the water in sandy areas. 
The spines of many stingrays are surprisingly long and jagged and a puncture wound can be intensely painful. While some toxin might be injected, the major danger is from an infection that is likely to result from a wound that does not get properly cleaned. Stingray spines are covered with bacteria and other growth, and as a result, cleaning the wound is especially important. Soaking the afflicted area in water that is as hot as can be tolerated will help break down toxins and alleviate pain. Professional medical treatment is advised.
The bodies of the coral-eating sea stars known as the crown-of-thorns are also covered in sharp spines. Puncture wounds can be very painful. While some divers have inadvertently settled onto a crown-of-thorns, most injuries occur when a diver, often a photographer, tries to handle them. 
Balloonfishes, puffers and porcupinefishes are also potential pokers, although they can also be classified as biters. Their bodies are covered with sharp spines. In some species the spines are always erect and in others the body must be inflated to erect the spines. The tips of the hardened spines are covered with mucus, and puncture wounds can result in infections if not properly treated. As you probably suspect, most injuries from these fishes occur when a diver is trying to handle them to make them inflate. (See sidebar.) However, the most serious injuries likely happen when an agitated fish bites the diver's hands or fingers. These species possess amazingly powerful jaws that are equipped with large, fused teeth. Enough said, I trust.

Miscellaneous Creatures To Be Aware Of
There are a number of marine animals that can injure divers but don't really fit into the previously discussed categories. Electric rays are a case in point. With most species the shock is not powerful enough to cause any serious injuries. Electric rays are rather slow, inefficient swimmers when compared with most other rays as some of the muscles that help other rays swim have been replaced with electricity-producing organs in electric rays. Be careful when settling onto sand bottoms in areas where electric rays are known to occur because they often bury themselves in soft substrates.
A variety of lobsters and crabs occasionally get blamed for injuring divers. Almost inevitably the injury is the result of a diver trying to grab one of these crustaceans and getting fingers and hands pinched and cut by the claws or the hard, spine-covered exoskeleton. Clearly the best way to avoid this type of injury is to wear very thick, rugged, protective gloves when taking crustaceans, and accept some risk.

Tips to Remember
Most human injuries from marine life are a result of defensive ' not aggressive ' action on the part of the animal. Avoid provoking any marine animal.
Practice good buoyancy control and be aware of your underwater surroundings in order to avoid injuring yourself or the reef.
If you sustain a sting, cut or scrape, be sure to apply first aid. Marine wounds, even minor abrasions, can easily become infected.

Pufferfish Revenge
In an effort to impress his girlfriend, a friend of mine grabbed a large porcupinefish and squeezed it until the fish inflated its body by swallowing water. As my friend turned his head to make sure his girlfriend was duly impressed, he accidentally got one of the fingers on his right hand too close to the fish's mouth. Big mistake. Porcupinefish can easily break up hard corals with their powerful jaws and fused teeth. The fish bit down on my friend's finger and immediately my pal knew he was in trouble. The good news was that he was quickly able to dislodge the fish from the finger on his right hand. The bad news was that while he was at it, the fish bit down on a finger on his left hand. 
The result was two lost fingernails, a dozen stitches and a humiliated pal whose girlfriend was ready to give up on him before the day was out.
The moral of this true tale is all too obvious. There might be a big price to pay if you hassle wildlife.