Dangerous Marine Organisms of Guam

by Capt. Alex Roth, Jr.

With respect to dangerous marine organisms, Guam is no different than any other area laved by waters of Mother Ocean, despite Guam's many charms. As a tropical island, Guam's waters contain more dangers than those in more temperate zones, such as Japan, Northern California or the U.S. east coast beaches from Virginia on north. However, this doesn't mean that the moment you step in the water you are in dire danger! Far from it: many of the hazards listed below you may never encounter, and with those that you do meet, by knowing in advance their potential danger you can avoid them.

Many hundreds of thousands of people have enjoyed the waters around Guam by using good common sense, and observing some routine safety practices. Some of these are: a) wear proper clothing and footwear to protect your feet from injury and your body from sunburn and contact with injurious organisms; b) do not handle organisms with which you are not familiar; c) never go alone into an area that is strange to you, and at night always go with another person regardless how well you know the area; d) don't put your hands or feet into a place before looking to see what's there; e) finally, leave word with someone ashore where you are going and when you expect to return. These five simple safety rules, if observed, will save you lots of grief.

LYNBYA ALGA SPECIES: a fine, filamentous bluegreen or blackishgreen alga commonly found tangled with other seaweeds on coral or reef flats, in tidepools or in deeper subtidal habitats. When fragments lodge inside bathing suits, they can cause inflammation of the skin, especially if the individual is allergic to algae.

Treatment: wash the affected area immediately with soap and water, and change bathing suits.

SPONGES: these are common around most shorelines and found to great depths. They occur is a large variety of sizes, shapes and colors. Body support of the sponge is provided by minute spicules of lime or glass or spongin fibers, either separately or in combination with spicules. When handled, spicules lodge under the skin, causing a burning or itching sensation. (Use gloves when handling sponges.)

Treatment: of several remedies, a good one is a paste made of unseasoned meat tenderizer mixed with alcohol. Apply for ten to twenty minutes, and then rinse off with alcohol. (If allergic to papaya, don't use this method, but apply cheap hard liquor, urine or isoproply alcohol, and rinse that off with dilute ammonia or a saturated baking soda solution.) Wear gloves when handling sponges, and don't rub up against them with your body, arms or legs.

HYDROZOA: these colonial organisms are sometimes mistaken for bluegreen alga. They are found, on floats, pilings, boat bottoms or in areas rich in nutrients such as the Agana Boat Basin area. The colonies have stinging cells like the jellyfish and Portuguese man–of–war: The sting causes burning, itching and a rash that can last from several hours to several days.

Treatment: same as for sponges. Don't brush up against structures and boat bottoms.

PORTUGUESE–MAN–OF–WAR: this is a transparent, gas–filled, bluish–purple float, up to 5 cm. wide, with numerous short tentacles and one very long one reaching down to 2 m. They float on the surface, propelled by the wind. The tentacles discharge a harmful toxin. If one is near, keep up wind and up current from it. If found washed up on the beach, avoid them as the tentacles remain toxic for many hours after the organism is dead. The sting produces prickling and stinging sensations, and sometimes blisters. Where people have severe sting or allergic reactions, or signs of difficult or irregular breathing and cardiac irregularities, emergency aid immediately.

Treatment: the same as or sponges. Remove the tentacles very carefully, preventing further contact with them. If nonallergic to papaya, apply green papaya to the area. Another remedy is direct application of urine.

JELLYFISH: These are self–propelling animals ranging in size from 11 cm. to over 30 cm. in diameter. They are found in calm water as well as the open ocean. Jellyfish produce the same kind of sting as does the Portuguese man–of–war, and the symptoms are similar.

Treatment: same as for the Portuguese man–of–war. Contact with jellyfish should be avoided, both in the water and on the beach.

SEA ANEMONES: several species can be found anchored to rocks on a hard substrate at most depths, but usually at or below the low water mark. They range in size from 1 mm. to 15 cm; most are pale in color or translucent with opaque white tentacles. Its stinging cells contain minute barbed spines. A sting can produce localized itching and burning, which vary from a prickly sensation to intense pain. Nausea, fever and headache are occasional allergic reactions.

Treatment: same as for the Portuguese man–of–war. When handling them (if you must!) for gosh sakes, wear gloves.

CORALS: Live coral grows down to a depth of about 80 m. The common stony corals are frequently coated with slime, and have many polyps with razor sharp edges. Pieces of coral can lodge in cuts (but do not grow there,) making them slow to heal and prone to bacterial infection. All corals have stinging cells that cause irritation.

Treatment: clean cuts and abrasions thoroughly with hydrogen peroxide to remove coral debris. Apply antiseptic or antibiotic powder/ointment as soon as possible, and update your antitetanus immunization as necessary. For irritation, see under Portuguese man–of–war. Handle corals with gloves, and avoid skin contact with them.

FIREWORMS (BRISTLEWORMS): this is a segmented worm that lives in dead coral heads, under rocks and on the, reef flats. They range from 1 to over 10 cm in length, and have thin, bristles on both sides of the body. These thin, sharp bristles can penetrate even very tough skin, and are tiny and curved; they are almost impossible to remove once lodged under the skin. Burning, itching and stinging results, and often the skin swells with individual punctures, becoming inflamed.

Treatment: if the skin is dry, sometimes the bristles can be removed with adhesive or scotch tape. Then the same as for Portuguese man–of–war. Wear gloves when turning over rocks to avoid contact with the worms.

CONES SHELLS: these mollusks are conical, with varying patterns on the shell. They frequently have an opaque periostracum outer skinlike covering which may cover the shell and hide its characteristics. They range in size from 1 to 12 cm, and are found in crevices in dead coral or rocks, under sand or under rocks, on the open reef, and in subsurface caverns. Although only the fish–eating Textile, Geography, Tulip, Striated and Marble cones are claimed fatal to man, all cones (and incidentally, Auger shells also) have the venom apparatus, and should be handled very discreetly. The venom is injected thru a puncture caused by a poison laden barb, ejected from the cone shell's proboscis, and the effect can be either a localized stinging or numbness with inflammation, to possible paralysis, coma, and rarely, death. Vomiting may occur shortly after the injury, and can last from 2 to 4 days.

Treatment: the area should be soaked in very hot (not scalding) water for 15 to 90 minutes. Because the toxins can be very dangerous, the victim should be treated at the nearest emergency medical facility as soon as possible. Update antitetanus immunization as necessary. Always pick up cone shells by the blunt end, preferably with tongs, and carry them in a rigid container thru which they can't penetrate with their proboscis

OCTOPI: this soft–bodied mollusk has a rounded sac–like body, with eight tentacles, and a beak located on the forward portion of the underside of the body. There are a number of species on Guam ranging from quite small to 2m. (including tentacles) in length. They are shy animals, and live in caves and holes, which can often be identified by the pile of shells, crustacean carcasses, etc. outside the entrance. Only one species, a small blue one, injects a dangerous toxin; other octopi bites cause skin wounds with lesser toxins injected into the wound from the salivary glands causing irritations similar to bee stings.

Treatment: for a blue octopus bite, treat as for a cone shell bite, with immediate emergency medical attention. For other octopi wounds, see under Corals. Don't stick your hand or arm into dark holes, especially if you see octopi signs around. When handling them, avoid the beak.

SEA URCHINS: There are a number of species around Guam, and all should be avoided. They grow to 25 cm. and over in diameter, and have spines varying from long, thin and brittle, to shorter and thickened. The long spines especially break off and remain embedded in the flesh, causing immediate throbbing pain, which can last for hours. If the spines aren't removed, an infection may develop.

Treatment: soak in very hot (not scalding) water for 15 to 90 minutes. Another. remedy is direct application of undiluted vinegar, or application of urine. Long embedded spines should be removed by a physician; unless you have surgically sterile instruments, don't try to operate yourself, as you may cause infection, apart from breaking off the spines in the wound thru ineptitude. When fossicking on the reef or reef flats, wear foot gear with thick soles, and use gloves when turning over rocks, etc. Don't put your arms, hands or feet where you haven't looked first.

CROWN–OF–THORNS STARFISH: The Acanthaster planci grows to 40 cm. and larger in diameter, and lives on corals, feeding on the polyps. It is greenish–red, and lives down to depths of 80 m., either singly or in colonies. The puncture wound from the short, sharp, poison coated spines produce immediate severe pain, and inflammation. Vomiting may occur shortly thereafter and can last from 2 to 4 days.

Treatment: remove loose spines, and have medical treatment for embedded ones. Then treat as for sea urchins, If you must handle this starfish, wear heavy gloves, and do so very cautiously.

CRABS: The crabs around Guam are extremely diverse in size, shape and color, and live in a great variety of habitats, ranging from the tidal zones and reef flats to great depths. Crab bites produce deep and painful wounds, and at least one species is poisonous. A bite from one of the latter (a small, tan colored creature,) should be treated as for a cone shell wound: get immediate medical attention. For others, wash with soap and water, apply antiseptic or antibiotic powder/ointment, and guard against infection.

SHARKS: On only very rare occasions do sharks enter the shallower lagoons, so – not to worry! In deeper waters, such as Apra Harbor, Umatac Bay, etc., sharks are present. Their reasons for attacking are unpredictable, and their presence should never be ignored. Their bite is a tearing, mutilating one, producing severe hemorrhaging, possible fracture or amputation. Due to its rough, sandpaper–like skin, abrasions may also be present.

Treatment: immediate medical aid must be obtained as soon as possible. Treat for shock by lying the person down, elevate the legs if possible, and maintain body heat. Control the bleeding by applying pressure and elevate the wounded area.

GREAT BARRACUDA: the adult fish are large, up to 2 m. in length, and swim offshore. Their severe bite produces wounds with straight lacerations, as compared to the curved and ragged gashes of the sharks. however, the results are generally the same.

Treatment: the same as for sharks.

STINGRAYS: these fish have a flat, triangular black or sand colored body up to 2 m. or more in width, with a long, whip–like barbed tail. They lie on the bottom in sandy areas. When stepped on or disturbed, the tail recoils and punctures the offender with the venomous spine. It produces lacerations and severe pain. As the tail whips around, the wound can be made anywhere on the body, appendages or head, and should be considered serious.

Treatment: Use the hot water treatment (as for cones), then clean the puncture area (see corals). Have a physician remove any embedded spines. When walking in the shallows over sandy areas, shuffle your feet as you move along.