SHARKS

The jaws of the shark contain rows of razor-sharp teeth, which can bite down with extreme force (Figure 184). The result is a wound with loss of tissue that bleeds freely and can lead rapidly to shock (see page 60).

Figure 184 Jaws of the great white shark, with advancing rows of razor-sharp ripsaw teeth.

The basic management of a major bleeding wound is described on page 54. Even if a shark bite appears minor, the wound should be washed out and bandaged, and the victim taken to a doctor. Often, the wound will contain pieces of shark teeth, seaweed, or sand debris, which must be removed to avoid a nasty infection. Like other animal bites, shark bites should not be sewn or taped tightly shut, to allow drainage. This helps prevent serious infection. The victim should be started on an antibiotic to oppose Vibrio bacteria (ciprofloxacin, trimethoprim-sulfamethoxazole, or doxycycline).

The skin of many sharks is rough, like sandpaper, and can cause a bad scrape. If this occurs, it should be managed similar to a second-degree burn (see page 108).

Shark Avoidance

1. Avoid shark-infested waters, particularly at dusk and after dark. Do not dive in known shark feeding grounds.

2. Swim in groups. Sharks tend to attack single swimmers.

3. When diving, avoid deep drop-offs, murky water, or areas near sewage outlets.

4. Do not tether captured (speared, for example) fish to your body.

5. Do not corner or provoke sharks.

6. If a shark appears, leave the water with slow, purposeful movements. Do not panic or splash. If a shark approaches you while you are diving in deep water, attempt to position yourself so that you are protected from the rear. If a shark moves in, attempt to strike a firm blow to the snout.

7. If you are stranded at sea and a rescue helicopter arrives to extract you from the water, exit the water at the earliest opportunity.

BARRACUDAS

Barracudas may bite victims and create nasty wounds with their long canine-like teeth (Figure 185). These wounds are managed similar to shark bites (see above). Because barracudas seem to be attracted to shiny objects, the swimmer, boater, or diver is advised to not wear bright metallic objects, particularly not a barrette in the hair or anklet dangled on a leg near the surface from a boat or dock.

Figure 185 Barracuda, with large canine-like teeth.

MORAY EELS

Although they look quite ferocious, moray eels (Figure 186) seldom attack humans, unless provoked. They have muscular jaws equipped with sharp fanglike teeth, which can inflict a vicious bite. A moray tends to bite and hold on; in some instances, it is necessary to break the eel’s jaws to get it to release.

Figure 186 Moray eel.

A moray bite should be managed similar to a shark bite (see page 354). Even if the bite is very small, it should be examined by a physician, to be sure that all tooth fragments have been removed. If the bite is more than superficial and on the hand, on the foot, or near a joint, the victim should be started on an antibiotic (ciprofloxacin, trimethoprim-sulfamethoxazole, or doxycycline) to oppose Vibrio bacteria. Avoid sewing or otherwise tightly closing a moray bite unless absolutely necessary.

SPONGES

Sponges handled directly from the ocean can cause two types of skin reaction. The first is an allergic type similar to that caused by poison oak (see page 234), with the difference that the reaction generally occurs within an hour after the sponge is handled. The skin becomes red, with burning, itching, and occasional blistering. The second type of reaction is caused by small spicules of silica from the sponges that are broken off and embedded in the outermost layers of the skin. This causes irritation, redness, and swelling. When large skin areas are involved, the victim may complain of fever, chills, fatigue, dizziness, nausea, and muscle cramps.

Because it is difficult to tell precisely which type of skin reaction has occurred, if a person develops a rash after handling a sponge, undertake the following therapy:

1. Soak the affected skin with white vinegar (5% acetic acid) for 15 minutes. This may be done by wetting a gauze pad or cloth with vinegar and laying it on the skin.

2. Dry the skin, and then apply the sticky side of adhesive tape to the skin and peel it off. This will remove most sponge spicules that are present. An alternative is to apply a thin layer of rubber cement or a commercial facial peel, let it dry and adhere to the skin, and then peel it off.

3. Repeat the vinegar soak for 15 minutes or apply rubbing (isopropyl 40%) alcohol for 1 minute.

4. Dry the skin, and then apply hydrocortisone lotion (0.5% to 1%) thinly twice a day until the irritation is gone. Do not use topical steroids before decontaminating with vinegar; this might worsen the reaction.

5. If the rash worsens (blistering, increasing redness or pain, swollen lymph glands), this may indicate an infection, and the victim should be started on an antibiotic to oppose Vibrio bacteria (ciprofloxacin, trimethoprim-sulfamethoxazole, or doxycycline). If the rash is persistent but there is no sign of infection, a 7-day course of oral prednisone in a tapering dose (for a 150 lb, or 68 kg, person, begin with 70 mg and decrease by 10 mg per day) may be helpful. Corticosteroids should always be taken with the understanding that a rare side effect is serious deterioration of the head (“ball” of the ball-and-socket joint) of the femur, the long bone of the thigh.

JELLYFISH

Jellyfish is the term commonly used to describe an enormous number of marine animals that are capable of inflicting a painful, and occasionally life-threatening, sting. These include fire coral, hydroids, jellyfish (including sea wasps), and anemones. The stings occur when the victim comes into contact with the creature—s tentacles or other appendages, which may carry millions of microscopic stinging cells (“cnidocytes”), each cell equipped with a toxin-laden microscopic stinging apparatus. Depending on the species, size, geographic location, time of year, and other natural factors, stings can range in severity from mild burning and skin redness to excruciating pain and severe blistering with generalized illness (nausea, vomiting, shortness of breath, muscle spasms, low blood pressure, and so on). Broken-off tentacles that are fragmented in the surf or washed up on the beach can retain their toxicity for months and should not be handled, even if they appear to be dried out and withered.

The dreaded box jellyfish (Chironex fleckeri) (Figure 187) of northern Australia and the Indo-Pacific contains one of the most potent animal venoms known. A sting from one of these creatures can induce death in minutes from cessation of breathing, abnormal heart rhythms, and profound low blood pressure (shock). A sting from the Irukandji (Carukia barnesi) causes a syndrome of muscle spasm (back pain), sweating, nausea and vomiting, high blood pressure, and perhaps death.