APPENDIX 5C — Dangerous Marine Animals 5C-1
This appendix provides general information on dangerous marine life
that may be encountered in diving operations.
It is beyond the scope of this manual to catalog all types of marine
encounters and potential injury. Planners should consult the recommended refer-
ences listed at the end of this appendix for more definite information. Medical
personnel are also a good source of information and should be consulted prior to
operating in unfamiliar waters. A good working knowledge of the marine environ-
ment should preclude lost time and severe injury.
Shark attacks on humans are infrequent. Since 1965, the annual recorded
number of shark attacks is only 40 to 100 worldwide. These attacks are unpredict-
able and injuries may result not only from bites, but also by coming in contact
with the shark’s skin. Shark skin is covered with very sharp dentine appendages,
called denticles, which are reinforced with tooth-like centers. Contact with shark
skin can lead to wide abrasions and heavy bleeding.
Shark Pre-Attack Behavior.
Pre-attack behavior by most sharks is somewhat
predictable. A shark preparing to attack swims with an exaggerated motion, its
pectoral fins pointing down in contrast to the usual flared out position, and it
swims in circles of decreasing radius around the prey. An attack may be heralded
by unexpected acceleration or other marked change in behavior, posture, or swim
patterns. Should surrounding schools of fish become unexplainably agitated,
sharks may be in the area. Sharks are much faster and more powerful than any
swimmer. All sharks must be treated with extreme respect and caution (see Figure
First Aid and Treatment.
Bites may result in a large amount of bleeding and tissue loss. Take immediate
action to control bleeding using large gauze pressure bandages. Cover wounds
with layers of compressive dressings preferably made with gauze, but easily
made from shirts or towels, and held in place by wrapping the wound tightly
with gauze, torn clothing, towels, or sheets. Direct pressure with elevation or
extreme compression on pressure points will control all but the most serious
bleeding. The major pressure points are: the radial artery pulse point for the
hand; above the elbow under the biceps muscle for the forearm (brachial
artery); and the groin area with deep finger-tip or heel-of-the-hand pressure for
bleeding from the leg (femoral artery). When bleeding cannot be controlled by
direct pressure and elevation or pressure points, a tourniquet or ligature may
5C-2 U.S. Navy Diving Manual—Volume 5
be needed to save the victim’s life even though there is the possibility of loss
of the limb. Tourniquets are applied only as a last resort and with only enough
pressure to control bleeding. Do not remove the tourniquet. The tourniquet
should be removed only by a physician in a hospital setting. Loosening of a
tourniquet may cause further shock by releasing toxins into the circulatory
system from the injured limb as well as continued blood loss.
Treat for shock by laying the patient down and elevating his feet.
If medical personnel are available, begin intravenous (IV) Ringers lactate or
normal saline with a large-bore cannula (16 or 18 ga). If blood loss has been
extensive, several liters should be infused rapidly. The patient’s color, pulse,
and blood pressure should be used as a guide to the volume of fluid required.
Maintain an airway and administer oxygen. Do not give fluids by mouth. If the
patients cardiovascular state is stable, narcotics may be administered in small
doses for pain relief. Observe closely for evidence of depressed respirations
due to the use of narcotics.
Initial stabilization procedures should include attention to the airway, breath-
ing, and circulation, followed by a complete evaluation for multiple trauma.
Transport the victim to a medical facility as soon as possible. Reassure the
Should a severed limb be retrieved, wrap it in bandages, moisten with saline,
place in a plastic bag and chill, but not in direct contact with ice. Transport the
severed limb with the patient.
Figure 5C-1.
Types of Sharks.
APPENDIX 5C — Dangerous Marine Animals 5C-3
Clean and debride wounds as soon as possible in a hospital or controlled envi-
ronment. Since shark teeth are cartilage, not bone, and may not appear on an
X-ray, operative exploration should be performed to remove dislodged teeth.
Consider X-ray evaluation for potential bone damage due to crush injury.
Severe crush injury may result in acute renal failure due to myoglobin released
from injured muscle, causing the urine to be a smoky brown color. Monitor
closely for kidney function and adjust IV fluid therapy appropriately.
Administer tetanus prophylaxis: Tetanus toxoid, 0.5 ml intramuscular (IM)
and tetanus immune globulin, 250 to 400 units IM.
Culture infected wounds for both aerobes and anaerobes before instituting
broad spectrum antibiotic coverage; secondary infections with Clostridium
and Vibrio species have been reported frequently.
Acute surgical repair, reconstructive surgery, and hyperbaric oxygen (HBO)
adjuvant therapy improving tissue oxygenation may all be needed.
In cases of unexplained decrease in mental status or other neurological signs
and symptoms following shark attack while diving, consider arterial gas
embolism or decompression sickness as a possible cause.
Killer Whales.
Killer whales live in all oceans, both tropical and polar. This whale
is a large mammal with a blunt, rounded snout and high black dorsal fin (Figure
5C-2). The jet black head and back contrast sharply with the snowy-white under-
belly. Usually, a white patch can be seen behind and above the eye. The killer
whale is usually observed in packs of 3 to 40 whales. It has powerful jaws, great
weight, speed, and interlocking teeth. Because of its speed and carnivorous habits,
this animal should be treated with great respect. There have been no recorded
attacks on humans.
Figure 5C-2.
5C-4 U.S. Navy Diving Manual—Volume 5
When killer whales are spotted, all personnel should immediately
leave the water. Extreme care should be taken on shore areas, piers, barges, ice
floes, etc., when killer whales are in the area.
First Aid and Treatment.
First aid and treatment would follow the same general
principles as those used for a shark bite (paragraph 5C-2.1.2).
Approximately 20 species of barracuda inhabit the oceans of the West
Indies, the tropical waters from Brazil to Florida and the Indo-Pacific oceans from
the Red Sea to the Hawaiian Islands. The barracuda is a long, thin fish with prom-
inent jaws and teeth, silver to blue in color, with a large head and a V-shaped tail
(Figure 5C-3). It may grow up to 10 feet long and is a fast swimmer, capable of
striking rapidly and fiercely. It will follow swimmers but seldom attacks an under-
water swimmer. It is known to attack surface swimmers and limbs dangling in the
water. Barracuda wounds can be distinguished from those of a shark by the tooth
pattern. A barracuda leaves straight or V-shaped wounds while those of a shark are
curved like the shape of its jaws. Life threatening attacks by barracuda are rare.
Barracuda are attracted by any bright object. Avoid wearing shiny
equipment or jewelry in waters when barracudas are likely to be present. Avoid
carrying speared fish, as barracuda will strike them. Avoid splashing or dangling
limbs in barracuda-infested waters.
First Aid and Treatment.
First aid and treatment follow the same general princi-
ples as those used for shark bites (paragraph 5C-2.1.2). Injuries are likely to be
less severe than shark bite injuries.
Moray Eels.
While some temperate zone species of the moray eel are known, it
primarily inhabits tropical and subtropical waters. It is a bottom dweller and is
commonly found in holes and crevices or under rocks and coral. It is snake-like in
both appearance and movement and has tough, leathery skin (Figure 5C-4). It can
grow to a length of 10 feet and has prominent teeth. A moray eel is extremely
territorial and attacks frequently result from reaching into a crevice or hole occu-
pied by the eel. It is a powerful and vicious biter and may be difficult to dislodge
after a bite is initiated. Bites from moray eels may vary from multiple small punc-
Figure 5C-3.
APPENDIX 5C — Dangerous Marine Animals 5C-5
ture wounds to the tearing, jagged type with profuse bleeding if there has been a
struggle. Injuries are usually inflicted on hands or forearms.
Extreme care should be used when reaching into holes or crevices.
Avoid provoking or attempting to dislodge an eel from its hole.
First Aid and Treatment.
Primary first aid must stop the bleeding. Direct pressure
and raising the injured extremity almost always controls bleeding. Arrange for
medical follow-up. Severe hand injuries should be evaluated immediately by a
physician. Mild envenomation may occur from a toxin that is released from the
palatine mucosa in the mouth of certain moray eels. The nature of this toxin is not
known. Treatment is supportive. Follow principles of wound management and
tetanus prophylaxis as in caring for shark bites. Antibiotic therapy should be insti-
tuted early. Immediate specialized care by a hand surgeon may be necessary for
tendon and nerve repair of the hand to prevent permanent damage and loss of
function of the hand.
Sea Lions.
The sea lion inhabits the Pacific Ocean and is numerous on the West
Coast of the United States. It resembles a large seal. Sea lions are normally harm-
less; however, during the breeding season (October through December) large bull
sea lions can become irritated and will nip at divers. Attempts by divers to handle
these animals may result in bites. These bites appear similar to dog bites and are
rarely severe.
Divers should avoid these mammals when in the water.
First Aid and Treatment.
Control local bleeding.
Clean and debride wound.
Figure 5C-4.
Moray Eel.
5C-6 U.S. Navy Diving Manual—Volume 5
Administer tetanus prophylaxis as appropriate.
Wound infections are common and prophylactic antibiotic therapy is advised.
Venomous Fish (Excluding Stonefish, Zebrafish, Scorpionfish).
of a fish following a sting is not always possible; however, symptoms and effects
of venom do not vary greatly. Venomous fish are rarely aggressive and usually
contact is made by accidentally stepping on or handling the fish. Dead fish spines
remain toxic (see Figure 5C-5). Venom is generally heat-labile and may be
decomposed by hot water. Local symptoms following a sting may first include
severe pain later combined with numbness or even hypersensitivity around the
wound. The wound site may become cyanotic with surrounding tissue becoming
pale and swollen. General symptoms may include nausea, vomiting, sweating,
mild fever, respiratory distress and collapse. The pain induced may seem dispro-
portionately high to apparent severity of the injury. Medical personnel should be
prepared for serious anaphylactic reactions from apparently minor stings or
Avoid handling suspected venomous fish. Venomous fish are often
found in holes or crevices or lying well camouflaged on rocky bottoms. Divers
should be alert for their presence and should take care to avoid them.
First Aid and Treatment.
Get victim out of water; watch for fainting.
Lay patient down and reassure.
Observe for signs of shock.
Figure 5C-5.
Venomous Fish. Shown is the weeverfish.
APPENDIX 5C — Dangerous Marine Animals 5C-7
Wash wound with cold, salt water or sterile saline solution. Surgery may be
required to open up the puncture wound. Suction is not effective to remove
this toxin.
Soak wound in hot water for 30 to 90 minutes. Heat may break down the
venom. The water should be as hot as the victim can tolerate but not hotter
than 122ºF (50ºC). Immersion in water above 122ºF (50ºC) for longer than a
brief period may lead to scalding. Immersion in water up to 122ºF (50ºC)
should therefore be brief and repeated as necessary. Use hot compresses if the
wound is on the face. Adding magnesium sulfate (epsom salts) to the water
offers no benefit.
Calcium gluconate injections, diazepam, or methocarbamol may help to
reduce muscle spasms. Infiltration of the wound with 0.5 percent to 2.0 per-
cent xylocaine with no epinephrine is helpful in reducing pain. If xylocaine
with epinephrine is mistakenly used, local necrosis may result from both the
toxin and epinephrine present in the wound. Narcotics may also be needed to
manage severe pain.
Clean and debride wound. Spines and sheath frequently remain. Be sure to
remove all of the sheath as it may continue to release venom.
Tourniquets or ligatures are no longer advised. Use an antiseptic or antibiotic
ointment and sterile dressing. Restrict movement of the extremity with immo-
bilizing splints and cravats.
Administer tetanus prophylaxis as appropriate.
Treat prophylactically with topical antibiotic ointment. If delay in treatment
has occurred, it is recommended that the wound be cultured prior to adminis-
tering systemic antibiotics.
Highly Toxic Fish (Stonefish, Zebra-fish, Scorpionfish).
Stings by stonefish, ze-
brafish, and scorpionfish have been known to cause fatalities. While many
similarities exist between these fish and the venomous fish of the previous section,
a separate section has been included because of the greater toxicity of their venom
and the availability of an antivenin. The antivenin is specific for the stonefish but
may have some beneficial effects against the scorpionfish and zebrafish. Local
symptoms are similar to other fish envenomation except that pain is more severe
and may persist for many days. Generalized symptoms are often present and may
include respiratory failure and cardiovascular collapse. These fish are widely dis-
tributed in temperate and tropical seas and in some arctic waters. They are
shallow-water bottom dwellers. Stonefish and scorpionfish are flattened vertically,
dark and mottled. Zebrafish are ornate and feathery in appearance with alternating
patches of dark and light color (see Figure 5C-6).
Prevention is the same as for venomous fish (paragraph 5C-3.1.1).
First Aid and Treatment.
5C-8 U.S. Navy Diving Manual—Volume 5
Give the same first aid as that given for venomous fish (paragraph 5C-3.1.2).
Observe the patient carefully for the possible development of life-threatening
complications. The venom is an unstable protein which acts as a myotoxin on
skeletal, involuntary, and cardiac muscle. This may result in muscular paraly-
sis, respiratory depression, peripheral vasodilation, shock, cardiac
dysrhythmias, or cardiac arrest.
Clean and debride wound.
Antivenin is available from Commonwealth Serum Lab, Melbourne, Australia
(see Reference 4 at end of this appendix for address and phone number). If
antivenin is used, the directions regarding dosage and sensitivity testing on the
accompanying package insert should be followed and the physician must be
ready to treat for anaphylactic shock (severe allergic reaction). In brief, one or
two punctures require 2,000 units (one ampule); three to four punctures, 4,000
units (two ampules); and five to six punctures, 6,000 units (three ampules).
Antivenin must be delivered by slow IV injection and the victim closely mon-
itored for anaphylactic shock.
Institute tetanus prophylaxis, analgesic therapy and antibiotics as described for
other fish stings.
Figure 5C-6.
Highly Toxic Fish.
APPENDIX 5C — Dangerous Marine Animals 5C-9
The stingray is common
in all tropical, subtropical, warm, and
temperate regions. It usually favors
sheltered water and will burrow into
sand with only eyes and tail exposed.
It has a bat-like shape and a long tail
(Figure 5C-7). Approximately 1,800
stingray attacks are reported annually
in the U.S. Most attacks occur when
waders inadvertently step on a ray,
causing it to lash out defensively with
its tail. The spine is located near the
base of the tail. Wounds are either of
the laceration or puncture type and
are extremely painful. The wound
appears swollen and pale with a blue rim. Secondary wound infections are
common. Systemic symptoms may be present and can include fainting, nausea,
vomiting, sweating, respiratory difficulty, and cardiovascular collapse.
In shallow waters which favor stingray habitation, shuffle feet on the
bottom and probe with a stick to alert the rays and chase them away.
First Aid and Treatment.
Give the same first aid as that given for venomous fish (paragraph 5C-3.1.2).
No antivenom is available.
Institute hot water therapy as described under fish envenomation.
Clean and debride wound. Removal of the spine may additionally lacerate tis-
sues due to retropointed barbs. Be sure to remove integumental sheath as it
will continue to release toxin.
Observe patient carefully for the possible development of life-threatening
complications. Symptoms can include cardiac dysrhythmias, hypotension,
vomiting, diarrhea, sweating, muscle paralysis, respiratory depression, and
cardiac arrest. Fatalities have been reported occasionally.
Institute tetanus prophylaxis, analgesic therapy, and broad-spectrum antibiot-
ics as described for fish envenomation.
Hazardous types of coelenterates include: Portuguese man-of-war,
sea wasp or box jellyfish, sea nettle, sea blubber, sea anemone, and rosy anemone
(Figure 5C-8). Jellyfish vary widely in color (blue, green, pink, red, brown) or
may be transparent. They appear to be balloon-like floats with tentacles dangling
down into the water. The most common stinging injury is the jellyfish sting. Jelly-
fish can come into direct contact with a diver in virtually any oceanic region,
worldwide. When this happens, the diver is exposed to literally thousands of
Figure 5C-7.
5C-10 U.S. Navy Diving Manual—Volume 5
minute stinging organs in the tentacles called nematocysts. Most jellyfish stings
result only in painful local skin irritation.
The sea wasp or box jellyfish and
Portuguese man-of-war are the
most dangerous types. The sea
wasp or box jellyfish (found in the
Indo-Pacific) can induce death
within 10 minutes by cardiovascu-
lar collapse, respiratory failure, and
muscular paralysis. Deaths from
Portuguese man-of-war stings have
also been reported. Even though in-
toxication from ingesting poisonous
sea anemones is rare, sea anemones
must not be eaten.
Do not handle jelly-
fish. Beached or apparently dead
specimens may still be able to sting.
Even towels or clothing contami-
nated with the stinging nematocysts
may cause stinging months later.
Avoidance of Tentacles.
In some species of jellyfish, tentacles may trail for great
distances horizontally or vertically in the water and are not easily seen by the
diver. Swimmers and divers should avoid close proximity to jellyfish to avoid
contacting their tentacles, especially when near the surface.
Protection Against Jellyfish.
Wet suits, body shells, or protective clothing should
be worn when diving in waters where jellyfish are abundant. Petroleum jelly
applied to exposed skin (e.g., around the mouth) helps to prevent stinging, but
caution should be used since petroleum jelly can deteriorate rubber products.
First Aid and Treatment.
Without rubbing, gently remove any remaining tenta-
cles using a towel or clothing. For preventing any further discharge of the stinging
nematocysts, use vinegar (dilute acetic acid) or a 3- to 10-percent solution of
acetic acid. An aqueous solution of 20 percent aluminum sulfate and 11 percent
surfactant (detergent) is moderately effective but vinegar works better. Do not use
alcohol or preparations containing alcohol. Methylated spirits or methanol, 100
percent alcohol and alcohol plus seawater mixtures have all been demonstrated to
cause a massive discharge of the nematocysts. In addition, these compounds may
also worsen the skin inflammatory reaction. Picric acid, human urine, and fresh
water also have been found to either be ineffective or even to discharge nemato-
cysts and should not be used. Rubbing sand or applying papain-containing meat
tenderizer is ineffective and may lead to further nematocysts discharge and should
not be used. It has been suggested that isopropyl (rubbing) alcohol may be effec-
tive. It should only be tried if vinegar or dilute acetic acid is not available.
Figure 5C-8.
Coelenterates. Hazardous
coelenterates include the Portuguese Man-
of-War (left) and the sea wasp (right).
APPENDIX 5C — Dangerous Marine Animals 5C-11
Symptomatic Treatment.
Symptomatic treatment can include topical steroid
therapy, anesthetic ointment (xylocaine, 2 percent) antihistamine lotion, systemic
antihistamines or analgesics. Benzocaine topical anesthetic preparations should
not be used as they may cause sensitization and later skin reactions.
Anaphylaxis (severe allergic reaction) may result from jellyfish
Antivenin is available to neutralize the effects of the sea wasp or box
jellyfish (Chironex fleckeri). The antivenin should be administered slowly through
an IV, with an infusion technique if possible. IM injection should be administered
only if the IV method is not feasible. One container (vial) of sea wasp antivenin
should be used by the IV route and three containers if injected by the IM route.
Each container of sea wasp antivenin is 20,000 units and is to be kept refrigerated,
not frozen, at 36-50ºF (2-10ºC). Sensitivity reaction to the antivenin should be
treated with a subcutaneous injection of epinephrine (0.3cc of 1:1,000 dilution),
corticosteroids, and antihistamines. Treat any hypotension (severely low blood
pressure) with IV volume expanders and pressor medication as necessary. The
antivenin may be obtained from the Commonwealth Serum Laboratories,
Melbourne, Australia (see Reference 4 for address and phone number).
Coral, a porous, rock-like formation, is found in tropical and subtropical
waters. Coral is extremely sharp and the most delicate coral is often the most
dangerous because of their razor-sharp edges. Coral cuts, while usually fairly
superficial, take a long time to heal and can cause temporary disability. The
smallest cut, if left untreated, can develop into a skin ulcer. Secondary infections
often occur and may be recognized by the presence of a red and tender area
surrounding the wound. All coral cuts should receive medical attention. Some
varieties of coral can actually sting a diver since coral is a coelenterate like jelly-
fish. Some of the soft coral of the genus Palythoa have been found recently to
contain the deadliest poison known to man. This poison is found within the body
of the organism and not in the stinging nematocysts. The slime of this coral may
cause a serious skin reaction (dermatitis) or even be fatal if exposed to an open
wound. No antidote is known.
Extreme care should be used when working near coral. Often coral is
located in a reef formation subjected to heavy surface water action, surface
current, and bottom current. Surge also develops in reef areas. For this reason, it is
easy for the unknowing diver to be swept or tumbled across coral with serious
consequences. Be prepared.
Protection Against Coral.
Coral should not be handled with bare hands. Feet
should be protected with booties, coral shoes or tennis shoes. Wet suits and protec-
tive clothing, especially gloves (neoprene or heavy work gloves), should be worn
when near coral.
First Aid and Treatment.
Control local bleeding.
5C-12 U.S. Navy Diving Manual—Volume 5
Promptly clean with hydrogen peroxide or 10-percent povidone-iodine solu-
tion and debride the wound, removing all foreign particles.
Cover with a clean dressing.
Administer tetanus prophylaxis as appropriate.
Topical antibiotic ointment has been proven very effective in preventing sec-
ondary infection. Stinging coral wounds may require symptomatic
management such as topical steroid therapy, systemic antihistamines, and
analgesics. In severe cases, restrict the patient to bed rest with elevation of the
extremity, wet-to-dry dressings, and systemic antibiotics. Systemic steroids
may be needed to manage the inflammatory reaction resulting from a combi-
nation of trauma and dermatitis.
The octopus inhabits tropical and temperate oceans. Species vary
depending on region. It has a large sac surrounded by 8 to 10 tentacles (Figure
5C-9). The head sac is large with well-developed eyes and horny jaws on the
mouth. Movement is made by jet action produced by expelling water from the
mantle cavity through the siphon. The octopus will hide in caves, crevices and
shells. It possesses a well-developed venom apparatus in its salivary glands and
stings by biting. Most species of octopus found in the U.S. are harmless. The blue-
ringed octopus common in Australian and Indo-Pacific waters may inflict fatal
bites. The venom of the blue-ringed octopus is a neuromuscular blocker called
tetrodotoxin and is also found in Puffer (Fugu) fish. Envenomation from the bite
of a blue-ringed octopus may lead to muscular paralysis, vomiting, respiratory
difficulty, visual disturbances, and cardiovascular collapse. Octopus bites consist
of two small punctures. A burning or tingling sensation results and may soon
spread. Swelling, redness, and inflammation are common. Bleeding may be severe
and the clotting ability of the blood is often retarded by the action of an anticoagu-
lant in the venom.
Figure 5C-9.
APPENDIX 5C — Dangerous Marine Animals 5C-13
Extreme care should be used when reaching into caves and crevices.
Regardless of size, an octopus should be handled carefully with gloves. One
should not spear an octopus, especially the large ones found off the coast of the
Northwestern United States, because of the risk of being entangled by its tentacles.
If killing an octopus becomes necessary, stabbing it between the eyes is
First Aid and Treatment.
Control local bleeding.
Clean and debride the wound and cover with a clean dressing.
For suspected blue-ringed octopus bites, do not apply a loose constrictive
band. Apply direct pressure with a pressure bandage and immobilize the
extremity in a position that is lower than the heart using splints and elastic
Be prepared to administer mouth-to-mouth resuscitation and cardiopulmonary
resuscitation if necessary.
Blue-ringed octopus venom is heat stable and acts as a neurotoxin and neuro-
muscular blocking agent. Venom is not affected by hot water therapy. No
antivenin is available.
Medical therapy for blue-ringed octopus bites is directed toward management
of paralytic, cardiovascular, and respiratory complications. Respiratory arrest
is common and intubation with mechanical ventilation may be required. Dura-
tion of paralysis is between 4 and 12 hours. Reassure the patient.
Administer tetanus prophylaxis as appropriate.
Segmented Worms (Annelida) (Examples: Bloodworm, Bristleworm).
This in-
vertebrate type varies according to region and is found in warm, tropical or
temperate zones. It is usually found under rocks or coral and is especially common
in the tropical Pacific, Bahamas, Florida Keys, and Gulf of Mexico. Annelida have
long, segmented bodies with stinging bristle-like structures on each segment.
Some species have jaws and will also inflict a very painful bite. Venom causes
swelling and pain.
Wear lightweight, cotton gloves to protect against bloodworms, but
wear rubber or heavy leather gloves for protection against bristleworms.
First Aid and Treatment.
Remove bristles with a very sticky tape such as adhesive tape or duct tape.
Topical application of vinegar will lessen pain.
5C-14 U.S. Navy Diving Manual—Volume 5
Treatment is directed toward relief of symptoms and may include topical ste-
roid therapy, systemic antihistamines, and analgesics.
Wound infection can occur but can be easily prevented by cleaning the skin
using an antiseptic solution of 10 percent povidone-iodine and topical antibi-
otic ointment. Systemic antibiotics may be needed for established secondary
infections that first need culturing, aerobically and anaerobically.
Sea Urchins.
There are various species of sea urchins with widespread distribu-
tion. Each species has a radial shape and long spines. Penetration of the sea urchin
spine can cause intense local pain due to a venom in the spine or from another type
of stinging organ called the globiferous pedicellariae. Numbness, generalized
weakness, paresthesias, nausea, vomiting, and cardiac dysrhythmias have been
Avoid contact with sea urchins. Even the short-spined sea urchin can
inflict its venom via the pedicellariae stinging organs. Protective footwear and
gloves are recommended. Spines can penetrate wet suits, booties, and tennis
First Aid and Treatment.
Remove large spine fragments gently, being very careful not to break them
into small fragments that remain in the wound.
Bathe the wound in vinegar or isopropyl alcohol. Soaking the injured extrem-
ity in hot water up to 122ºF (50ºC) may help. Caution should be used to
prevent scalding the skin which can easily occur after a brief period in water
above 122ºF (50ºC).
Clean and debride the wound. Topical antibiotic ointment should be used to
prevent infection. Culture both aerobically and anaerobically before adminis-
tering systemic antibiotics for established secondary infections.
Remove as much of the spine as possible. Some small fragments may be
absorbed by the body. Surgical removal, preferably with a dissecting micro-
scope, may be required when spines are near nerves and joints. X-rays may be
required to locate these spines. Spines can form granulomas months later and
may even migrate to other sites.
Allergic reaction and bronchospasm can be controlled with subcutaneous epi-
nephrine (0.3 cc of 1:1,000 dilution) and by using systemic antihistamines.
There are no specific antivenins available.
Administer tetanus prophylaxis as appropriate.
Get medical attention for deep wounds.
APPENDIX 5C — Dangerous Marine Animals 5C-15
Cone Shells.
The cone shell is widely distrib-
uted in all regions and is usually found under
rocks and coral or crawling along sand. The
shell is most often symmetrical in a spiral coil,
colorful, with a distinct head, one to two pairs
of tentacles, two eyes, and a large flattened foot
on the body (Figure 5C-10). A cone shell sting
should be considered as severe as a poisonous
snake bite. It has a highly developed venom
apparatus: venom is contained in darts inside
the proboscis which extrudes from the narrow
end but is able to reach most of the shell. Cone
shell stings are followed by a stinging or
burning sensation at the site of the wound.
Numbness and tingling begin at the site of the
wound and may spread to the rest of the body;
involvement of the mouth and lips is severe.
Other symptoms may include muscular paral-
ysis, difficulty with swallowing and speech,
visual disturbances, and respiratory distress.
Avoid handling cone shells. Venom can be injected through clothing
and gloves.
First Aid and Treatment.
Lay the patient down.
Do not apply a loose constricting band or ligature. Direct pressure with a pres-
sure bandage and immobilization in a position lower than the level of the heart
using splints and elastic bandages is recommended.
Some authorities recommend incision of the wound and removal of the venom
by suction, although this is controversial. However, general agreement is that
if an incision is to be made, the cuts should be small (one centimeter), linear
and penetrate no deeper than the subcutaneous tissue. The incision and suction
should only be performed if it is possible to do so within two minutes of the
sting. Otherwise, the procedure may be ineffective. Incision and suction by
inexperienced personnel has resulted in inadvertent disruption of nerves, ten-
dons, and blood vessels.
Transport the patient to a medical facility while ensuring that the patient is
breathing adequately. Be prepared to administer mouth-to-mouth resuscitation
if necessary.
Cone shell venom results in paralysis or paresis of skeletal muscle, with or
without myalgia. Symptoms develop within minutes of the sting and effects
can last up to 24 hours.
Figure 5C-10.
Cone Shell.
5C-16 U.S. Navy Diving Manual—Volume 5
No antivenin is available.
Respiratory distress may occur due to neuromuscular block. Patient should be
admitted to a medical facility and monitored closely for respiratory or cardio-
vascular complications. Treat as symptoms develop.
Local anesthetic with no epinephrine may be injected into the site of the
wound if pain is severe. Analgesics which produce respiratory depression
should be used with caution.
Management of severe stings is supportive. Respiration may need to be sup-
ported with intubation and mechanical ventilation.
Administer tetanus prophylaxis as appropriate.
Sea Snakes.
The sea snake is an air-breathing reptile which has adapted to its
aquatic environment by developing a paddle tail. Sea snakes inhabit the Indo-
Pacific area and the Red Sea and have been seen 150 miles from land. The most
dangerous areas in which to swim are river mouths, where sea snakes are more
numerous and the water more turbid. The sea snake is a true snake, usually 3 to 4
feet in length, but it may reach 9 feet. It is generally banded (Figure 5C-11). The
sea snake is curious and is often attracted by divers and usually is not aggressive
except during its mating season.
Sea Snake Bite Effects.
The sea snake injects a poison that has 2 to 10 times the
toxicity of cobra venom. The bites usually appear as four puncture marks but may
range from one to 20 punctures. Teeth may remain in the wound. The neurotoxin
poison is a heat-stable nonenzymatic protein; hence, sea snake bites should not be
immersed in hot water as with venomous fish stings. Due to its small jaws, bites
often do not result in envenomation. Sea snake bites characteristically produce
little pain and there is usually a latent period of 10 minutes to as long as several
hours before the development of generalized symptoms: muscle aching and stiff-
ness, thick tongue sensation, progressive paralysis, nausea, vomiting, difficulty
Figure 5C-11.
APPENDIX 5C — Dangerous Marine Animals 5C-17
with speech and swallowing, respiratory distress and failure, plus smoky-colored
urine from myoglobinuria, which may go on to kidney failure.
Wet suits or protective clothing, especially gloves, may provide
substantial protection against bites and should be worn when diving in waters
where sea snakes are abundant. Also, shoes should be worn when walking where
sea snakes are known to exist, including in the vicinity of fishing operations. Do
not handle sea snakes. Bites often occur on the hands of fishermen attempting to
remove snakes from nets.
First Aid and Treatment.
Keep victim still.
Do not apply a loose constricting band or tourniquet. Apply direct pressure
using a compression bandage and immobilize the extremity in the dependent
position with splints and elastic bandages. This prevents spreading of the neu-
rotoxin through the lymphatic circulation.
Incise and apply suction (see cone shell stings, paragraph 5C-3.9).
Transport all sea snake-bite victims to a medical facility as soon as possible,
regardless of their current symptoms.
Watch to ensure that the patient is breathing adequately. Be prepared to
administer mouth-to-mouth resuscitation or cardiopulmonary resuscitation if
The venom is a heat-stable protein which blocks neuromuscular transmission.
Myonecrosis with resultant myoglobinuria and renal damage are often seen.
Hypotension may develop.
Respiratory arrest may result from generalized muscular paralysis; intubation
and mechanical ventilation may be required.
Renal function should be closely monitored and peritoneal or hemodialysis
may be needed. Alkalinization of urine with sufficient IV fluids will promote
myoglobin excretion. Monitor renal function and fluid balance anticipating
acute renal failure.
Vital signs should be monitored closely. Cardiovascular support plus oxygen
and IV fluids may be required.
Because of the possibility of delayed symptoms, all sea snake-bite victims
should be observed for at least 12 hours.
If symptoms of envenomation occur within one hour, antivenin should be
administered as soon as possible. In a seriously envenomated patient, antive-
nin therapy may be helpful even after a significant delay. Antivenin is
5C-18 U.S. Navy Diving Manual—Volume 5
available from the Commonwealth Serum Lab in Melbourne, Australia (see
Reference D of this appendix for address and phone number). If specific anti-
venin is not available, polyvalent land snake antivenin (with a tiger snake or
krait Elapidae component) may be substituted. If antivenin is used, the direc-
tions regarding dosage and sensitivity testing on the accompanying package
insert should be followed and the physician must be ready to treat for anaphy-
laxis (severe allergic reaction). Infusion by the IV method or closely
monitored drip over a period of one hour, is recommended.
Administer tetanus prophylaxis as appropriate.
Sponges are composed of minute multicellular animals with spicules of
silica or calcium carbonate embedded in a fibrous skeleton. Exposure of skin to
the chemical irritants on the surface of certain sponges or exposure to the minute
sharp spicules can cause a painful skin condition called dermatitis.
Avoid contact with sponges and wear gloves when handling live
First Aid and Treatment.
Adhesive or duct tape can effectively remove the sponge spicules.
Vinegar or 3- to 10-percent acetic acid should be applied with saturated com-
presses as sponges may be secondarily inhabited by stinging coelenterates.
Antihistamine lotion (diphenhydra-mine) and later a topical steroid (hydrocor-
tisone), may be applied to reduce the early inflammatory reaction.
Antibiotic ointment is effective in reducing the chance of a secondary
Ciguatera Fish Poisoning.
Ciguatera poisoning is fish poisoning caused by eating
the flesh of a fish that has eaten a toxin-producing microorganism, the dinoflagel-
late, Gambierdiscus toxicus. The poisoning is common in reef fish between
latitudes 35ºN and 35ºS around tropical islands or tropical and semitropical shore-
lines in Southern Florida, the Caribbean, the West Indies, and the Pacific and
Indian Oceans. Fish and marine animals affected include barracuda, red snapper,
grouper, sea bass, amberjack, parrot fish, and the moray eel. Incidence is unpre-
dictable and dependent on environmental changes that affect the level of
dinoflagellates. The toxin is heat-stable, tasteless, and odorless, and is not
destroyed by cooking or gastric acid. Symptoms may begin immediately or within
several hours of ingestion and may include nausea, vomiting, diarrhea, itching and
muscle weakness, aches and spasms. Neurological symptoms may include pain,
ataxia (stumbling gait), paresthesias (tingling), and circumoral parasthesias
(numbness around the mouth). Sensory reversal of hot and cold sensation when
touching or eating objects of extreme temperatures may occur. In severe cases,
APPENDIX 5C — Dangerous Marine Animals 5C-19
respiratory failure and cardiovascular collapse may occur. Pruritus (itching) is
characteristically made worse by alcohol ingestion. Gastrointestinal symptoms
usually disappear within 24 to 72 hours. Although complete recovery will occur in
the majority of cases, neurological symptoms may persist for months or years.
Signs and symptoms of ciguatera fish poisoning may be misdiagnosed as decom-
pression sickness or contact dermatitis from unseen fire coral or jellyfish. Because
of rapid modern travel and refrigeration, ciguatera poisoning may occur far from
endemic areas with international travelers or unsuspecting restaurant patrons.
Never eat the liver, viscera, or roe (eggs) of tropical fish. Unusually
large fish of a species should be suspected. When traveling, consult natives
concerning fish poisoning from local fish, although such information may not
always be reliable. A radioimmunoassay has been developed to test fish flesh for
the presence of the toxin and soon may be generally available.
First Aid and Treatment.
Treatment is largely supportive and symptomatic. If the time since suspected
ingestion of the fish is brief and the victim is fully conscious, induce vomiting
(syrup of Ipecac) and administer purgatives (cathartics, laxatives) to speed the
elimination of undigested fish.
In addition to the symptoms described above, other complications which may
require treatment include hypotension and cardiac dysrhythmias.
Antiemetics and antidiarrheal agents may be required if gastrointestinal symp-
toms are severe. Atropine may be needed to control bradycardia. IV fluids
may be needed to control hypotension. Calcium gluconate, diazepam, and
methocarbamol can be given for muscle spasm.
Amytriptyline has been used successfully to resolve neurological symptoms
such as depression.
Cool showers may induce pruritus (itching).
Scombroid Fish Poisoning.
Unlike ciguatera fish poisoning (see paragraph
5C-4.1), where actual toxin is already concentrated in the flesh of the fish, scom-
broid fish poisoning occurs from different types of fish that have not been
promptly cooled or prepared for immediate consumption. Typical fish causing
scombroid poisoning include tuna, skipjack, mackerel, bonito, dolphin fish, mahi
mahi (Pacific dolphin), and bluefish. Fish that cause scombroid poisoning are
found in both tropical and temperate waters. A rapid bacterial production of hista-
mine and saurine (a histamine-like compound) produce the symptoms of a
histamine reaction: nausea, abdominal pain, vomiting, facial flushing, urticaria
(hives), headache, pruritus (itching), bronchospasm, and a burning or itching
sensation in the mouth. Symptoms may begin one hour after ingestion and last 8 to
12 hours. Death is rare.
5C-20 U.S. Navy Diving Manual—Volume 5
Immediately clean the fish and preserve by rapid chilling. Do not eat
any fish that has been left in the sun or in the heat longer than two hours.
First Aid and Treatment.
Oral antihistamine, (e.g., diphenhydramine, cimetidine),
epinephrine (given subcutaneously), and steroids are to be given as needed.
Puffer (Fugu) Fish Poisoning.
An extremely potent neurotoxin called tetrodot-
oxin is found in the viscera, gonads, liver, and skin of a variety of fish, including
the puffer fish, porcupine fish, and ocean sunfish. Puffer fish—also called blow
fish, toad fish, and balloon fish, and called Fugu in Japanese—are found primarily
in the tropics but also in temperate waters of the coastal U.S., Africa, South
America, Asia, and the Mediterranean. Puffer fish is considered a delicacy in
Japan, where it is thinly sliced and eaten as sashimi. Licensed chefs are trained to
select those puffer fish least likely to be poisonous and also to avoid contact with
the visceral organs known to concentrate the poison. The first sign of poisoning is
usually tingling around the mouth, which spreads to the extremities and may lead
to a bodywide numbness. Neurological findings may progress to stumbling gait
(ataxia), generalized weakness, and paralysis. The victim, though paralyzed,
remains conscious until death occurs by respiratory arrest.
Avoid eating puffer fish. Cooking the poisonous flesh will not
destroy the toxin.
First Aid and Treatment.
Provide supportive care with airway management and monitor breathing and
Monitor anal function.
Monitor and treat cardiac dysrhythmias.
Paralytic Shellfish Poisoning (PSP) (Red Tide).
Paralytic shellfish poisoning
(PSP) is due to mollusks (bivalves) such as clams, oysters, and mussels ingesting
dinoflagellates that produce a neurotoxin which then affects man. Proliferation of
these dinoflagellates during the warmest months of the year produce a character-
istic red tide. However, some dinoflagellate blooms are colorless, so that
poisonous mollusks may be unknowingly consumed. Local public health authori-
ties must monitor both seawater and shellfish samples to detect the toxin.
Poisonous shellfish cannot be detected by appearance, smell, or discoloration of
either a silver object or a garlic placed in the cooking water. Also, poisonous shell-
fish can be found in either low or high tidal zones. The toxic varieties of
dinoflagellates are common in the following areas: Northwestern U.S. and
Canada, Alaska, part of western South America, Northeastern U.S., the North Sea
European countries, and in the Gulf Coast area of the U.S. One other type of
dinoflagellate, though not toxic if ingested, may lead to eye and respiratory tract
irritation from shoreline exposure to a dinoflagellate bloom that becomes aero-
solized by wave action and wind.
APPENDIX 5C — Dangerous Marine Animals 5C-21
Symptoms of bodywide PSP include circumoral paresthesias
(tingling around the mouth) which spreads to the extremities and may progress to
muscle weakness, ataxia, salivation, intense thirst, and difficulty in swallowing.
Gastrointestinal symptoms are not common. Death, although uncommon, can
result from respiratory arrest. Symptoms begin 30 minutes after ingestion and may
last for many weeks. Gastrointestinal illness occurring several hours after inges-
tion is most likely due to a bacterial contamination of the shellfish (see paragraph
5C-4.5). Allergic reactions such as urticaria (hives), pruritus (itching), dryness or
scratching sensation in the throat, swollen tongue and bronchospasm may also be
an individual hypersensitivity to a specific shellfish and not PSP.
Since this dinoflagellate is heat stable, cooking does not prevent
poisoning. The broth or bouillon in which the shellfish is boiled is especially
dangerous since the poison is water-soluble and will be found concentrated in the
First Aid and Treatment.
No antidote is known. If the victim is fully conscious, induce vomiting with
30cc (two tablespoons) of syrup of Ipecac. Lavaging the stomach with alkaline
fluids (solution of baking soda) may be helpful since the poison is acid-stable.
Provide supportive treatment with close observation and advanced life support
if needed until the illness resolves. The poisoning is also related to the quantity
of poisonous shellfish consumed and the concentration of the dinoflagellate
Bacterial and Viral Diseases from Shellfish.
Large outbreaks of typhoid fever
and other diarrheal diseases caused by the genus Vibrio have been traced to
consuming contaminated raw oysters and inadequately cooked crabs and shrimp.
Diarrheal stool samples from patients suspected of having bacterial and viral
diseases from shellfish should be placed on a special growth medium (thiosulfate-
citrate-bile salts-sucrose agar) to specifically grow Vibrio species, with isolates
being sent to reference laboratories for confirmation.
To avoid bacterial or viral disease (e.g., Hepatitus A or Norwalk
viral gastroenteritis) associated with oysters, clams, and other shellfish, an indi-
vidual should eat only thoroughly cooked shellfish. It has been proven that eating
raw shellfish (mollusks) presents a definite risk of contracting disease.
First Aid and Treatment.
Provide supportive care with attention to maintaining fluid intake by mouth or
IV if necessary.
Consult medical personnel for treatment of the various Vibrio species that may
be suspected.
5C-22 U.S. Navy Diving Manual—Volume 5
Sea Cucumbers.
The sea cucumber is frequently eaten in some parts of the world
where it is sold as Trepang or Beche-de-mer. It is boiled and then dried in the sun
or smoked. Contact with the liquid ejected from the visceral cavity of some sea
cucumber species may result in a severe skin reaction (dermatitis) or even blind-
ness. Intoxication from sea cucumber ingestion is rare.
Local inhabitants can advise about the edibility of sea cucumbers in
that region. However, this information may not be reliable. Avoid contact with
visceral juices.
First Aid and Treatment.
Because no antidote is known, treatment is only symp-
tomatic. Skin irritation may be treated like jellyfish stings (paragraph 5C-3.4.4).
Parasitic Infestation.
Parasitic infestations can be of two types: superficial and
flesh. Superficial parasites burrow in the flesh of the fish and are easily seen and
removed. These may include fish lice, anchor worms, and leeches. Flesh parasites
can be either encysted or free in the muscle, entrails, and gills of the fish. These
parasites may include roundworms, tapeworms, and flukes. If the fish is inade-
quately cooked, these parasites can be passed on to humans.
Avoid eating raw fish. Prepare all fish by thorough cooking or hot-
smoking. When cleaning fish, look for mealy or encysted areas in the flesh; cut out
and discard any cyst or suspicious areas. Remove all superficial parasites. Never
eat the entrails or viscera of any fish.
Prevention and Treatment of Dangerous Marine Animal Injuries, a publica-
tion by International Bio-toxicological Centre, World Life Research Institute,
Colton, CA; November 1982; P.S. Auerbach and B.W. Halstead.
Management of Wilderness and Environmental Emergencies, Macmillan Pub-
lishing Co., New York, N. Y., 1983. Eds. P.S. Auerbach and E.C. Greehr.
The Life of Sharks, Columbia University Press, New York 1971. P. Budkur.
Commonwealth Serum Laboratories, 45 Poplar Road, Parkville, Melbourne,
Victoria, Australia; Telephone Number: 011-61-3-389-1911, Telex
Sharks. Doubleday, Garden City, N.Y., 1970. J. Y. Cousteau.
Fish and Shellfish Acquired Diseases. American Family Physician. Vol 24:
pp. 103-108, 1981. M. L. Dembert, K. Strosahl and R. L. Bumgarner.
Consumption of Raw Shellfish - Is the Risk Now Unacceptable? New England
Journal of Medicine. Vol 314: pp.707-708, 1986. H. L. DuPont.
APPENDIX 5C — Dangerous Marine Animals 5C-23
Diving and Subaquatic Medicine, Diving Medical Centre, Masman N.S.W.,
Australia; 1981, Second edition; C. Edmonds, C. Lowry and C. Pennefather.
Poisonous and Venomous Marine Animals of the World, Darwin Press Inc.,
Princeton, NJ; 1978; B. W. Halstead.
Principles and Practice of Emergency Medicine, W. B. Saunders Co., Phila-
delphia, PA; 1978, pp. 812-815; G. Schwartz, P. Sofar, J. Stone, P. Starey and
D. Wagner.
Dangerous Marine Creatures, Reed Book Ptg., Ltd., 2 Aquatic Drive,
French’s Forest, NSW 20806 Austrailia. C. Edmonds.
A Medical Guide to Hazardous Marine Life, Second Edition, Mosby Year-
book, 1991, P.S. Auerbach.
5C-24 U.S. Navy Diving Manual—Volume 5