Underwater Dangers : A Diver’s Guide to Marine Life Hazards
Written by Urval Patel, 26 August 2024.
Scuba diving offers a mesmerizing window into the underwater world, where vibrant marine life and stunning seascapes captivate adventurers. However, this exhilarating activity is not without its risks. Among the most significant concerns for divers are marine hazards—natural threats that can range from subtle and easily overlooked dangers to more obvious and potentially life-threatening situations. Understanding these hazards is crucial for ensuring a safe and enjoyable diving experience.
This is the first in a series of article that looks at marine hazards, from venomous creatures, sharp corals and unpredictable behaviour of marine animals (this article), to challenges posed by strong currents and surges (Environmental Hazards), and finally underwater structures and debris, barotrauma, equipment failure (Physical Hazards and Human Errors). These articles provide an introduction to the common marine hazards every divers should be aware of to navigate the underwater realm safely.
1. Venomous Creatures
The underwater world is home to a variety of venomous creatures. While most are not aggressive, accidental encounters can lead to painful and, in some cases, life-threatening injuries.
Jellyfish:
Box Jellyfish: Known as one of the most dangerous jellyfish species, the box jellyfish can deliver a sting that is not only excruciatingly painful but also potentially fatal. Its tentacles contain nematocysts that release venom upon contact, causing intense pain, cardiac arrest, or even death within minutes. Divers should be cautious in areas known to harbour box jellyfish and wear protective clothing if necessary.
Portuguese Man O’ War: Although not a true jellyfish, this creature is often mistaken for one. Its long, trailing tentacles can cause severe stings even if the organism is dead and washed ashore.
Lionfish and Scorpionfish:
Lionfish: These striking fish, with their feathery fins and vivid stripes, are a common sight in many tropical waters. However, their spines contain venom that can cause extreme pain, swelling, and in rare cases, more severe symptoms such as difficulty breathing or heart problems. Lionfish are not aggressive but will defend themselves if threatened.
Scorpionfish: Well-camouflaged and often hidden among rocks and coral, scorpionfish can deliver a painful sting if accidentally touched. Like lionfish, their venom can cause intense pain and requires immediate medical attention to avoid complications.
Stingrays:
Stingrays are generally docile creatures, often found resting on the sandy sea floor. However, if a diver accidentally steps on or disturbs a stingray, it may defend itself by lashing out with its venomous barb. The resulting wound can be extremely painful and may lead to infection if not properly treated. Divers should shuffle their feet when walking in shallow waters to avoid surprising a stingray.
Sea Snakes:
Sea snakes are among the most venomous reptiles in the world, with venom that is far more potent than that of many land snakes. Despite this, they are generally not aggressive and rarely pose a threat to divers unless provoked. Sea snakes are usually curious but non-confrontational, often approaching divers out of curiosity rather than aggression. However, if threatened or handled, they can deliver a bite that, while painless at first, can lead to severe symptoms, including paralysis and respiratory failure. Divers should avoid touching or attempting to interact with sea snakes and remain calm if one approaches.
2. Biting and Stinging Animals
While encounters with these animals are rare, knowing how to respond to their presence can make a significant difference in a diver’s safety.
Sharks:
Despite their fearsome reputation, most sharks pose little threat to divers. However, certain species, such as great whites, tiger sharks, and bull sharks, can be dangerous, particularly if they feel threatened or mistake a diver for prey. Divers should avoid erratic movements, refrain from spearfishing (which can attract sharks), and maintain a calm demeanour if a shark is sighted. Understanding shark behaviour and recognizing the signs of potential aggression can help prevent incidents.
Moray Eels:
These snake-like fish are often found lurking in crevices and under rocks. Moray eels have poor eyesight and rely on their sense of smell to hunt, so they may bite if they mistake a diver’s hand or gear for food. Their sharp teeth can cause deep puncture wounds that are prone to infection. Divers should avoid placing their hands in crevices and should give these animals plenty of space.
Titan Triggerfish:
Titan Triggerfish, while not venomous, are known for their aggressive behaviour, particularly during nesting season. These fish fiercely guard their nests and may attack divers who venture too close. A Titan Triggerfish can inflict a painful bite with its strong jaws and sharp teeth, and it may persistently chase a diver until the perceived threat is far from its territory. Recognizing the signs of an aggressive Titan Triggerfish, such as facing the intruder head-on and erecting its dorsal spine, can help divers avoid confrontation. If a Titan Triggerfish begins to show aggression, it is best to slowly back away while keeping an eye on the fish.
3. Coral and Fire Coral
While coral reefs are beautiful and essential to marine ecosystems, they can also pose hazards to divers.
Coral:
Sharp corals can cause cuts and scrapes if brushed against, which can be slow to heal due to the presence of bacteria and other microorganisms in seawater. Additionally, coral can be fragile, and contact with it can damage these delicate ecosystems. Divers should practice good buoyancy control and avoid touching or standing on coral. Check out Flow DC’s buoyancy workshops to help you master the art of buoyancy through proper breathing & finning methods.
Fire Coral:
Despite its name, fire coral is not a true coral but a type of hydrozoan. Its surface is covered with small, stinging nematocysts that can cause a burning sensation, itching, and rash upon contact. The sting is usually mild but can be quite painful, especially if a large area of skin is affected. Fire coral is often found in areas where divers might inadvertently brush against it, so caution is advised when swimming near reefs.
4. Sea Urchins
Sea urchins are spiny, round creatures that dwell on the ocean floor, often in rocky areas and coral reefs.
Sea Urchin Injuries:
If a diver accidentally steps on or touches a sea urchin, the sharp spines can puncture the skin, causing pain and potential infection. In some cases, the spines may break off under the skin, requiring medical removal. Some sea urchins, like the flower urchin, also possess venomous spines that can cause more severe reactions. Divers should be mindful of where they place their hands and feet and wear appropriate protective footwear when walking in areas where sea urchins are common.
Preventative Measures For Divers
To minimize the risk of encountering these marine hazards, divers should adhere to the following guidelines:
- Learn and respect local marine life: Before diving, familiarize yourself with the types of marine life you might encounter and understand their behaviors. Respecting their space and avoiding sudden movements can reduce the likelihood of negative encounters.
- Practice good buoyancy control: Maintaining proper buoyancy is key to avoiding accidental contact with hazardous marine life, such as fire coral or sea urchins.
- Wear appropriate gear: In areas known for jellyfish or stingrays, consider wearing protective clothing such as full-body wetsuits or stingray guards.
- Dive with a buddy: Always dive with a buddy who can assist in case of an emergency, and ensure that both of you are aware of the potential hazards in the area.
- Avoid touching marine life: As a general rule, refrain from touching any marine creatures, both for your safety and to protect the delicate marine ecosystem.
- Be aware of your surroundings: Constantly scan your surroundings and be mindful of where you are placing your hands, feet, and body. Avoid reaching into crevices or holes where creatures like moray eels may be hiding.
Worried about how to react under these circumstances or how to help other divers? Learn how to prevent and manage emergency situations when you sign up for our PADI Rescue Course & EFR course. Better be safe than sorry! And remember, while some of these marine life are hazardous, it doesn’t mean that they are not amazing to see during dives. Do check out our dive trips for a chance to spot all these creatures and more.
For more information, WhatsApp or email us at hello@flowdive.center.