Nusa Penida's most dangerous sea creatures

Nusa Penida is renowned for its crystal-clear waters, teeming with vibrant marine life. While this Indonesian island is a dream destination for divers, it's essential to remember that the ocean is a wild place. Beneath the surface lurks a fascinating array of creatures, some of which can pose a potential threat. This blog post will shed light on the most dangerous sea creatures you might encounter during your Nusa Penida adventure, equipping you with the knowledge to stay safe while exploring this underwater wonderland.

Definitely one to watch out for, the Titan trigger fish...

Titan Triggerfish

Like most tropical waters in the Indo-Pacific, Nusa Penida is home to the infamous and feared Titan triggerfish. This large leathery-skinned fish is responsible for most of the marine creature-inflicted wounds in these oceans. This highly aggressive fish protects its nest with great zeal and has been known to chase innocent divers over a few hundred metres. The bite it can inflict is on a par with a big mean dog and can mean stitches. Attacks are very common in nesting season (here around November) so when you see this easily identifiable species of triggerfish (the other species are totally chilled), keep an eye out and keep your distance. If it starts to swim erratically towards you swim backwards out of the area keeping an eye on it with your fins between you and the tetchy creature. The territory it seeks to protect has a V shape originating where the nest is and rising towards the surface so if chased stay at depth and swim out of the area, do not swim to the surface.

Danger level: (on a scale from 1 to 10): 4 (like a big dog bite)

Blue ring octopus

So this adorable little octopus can grow up to 12cm. It mostly looks a browny beige colour and is a master of disguise. However, when stressed, electric iridescent blue rings appear all over its body. It is occasionally spotted at Manta Point and other rocky Nusa Penida dive sites. Don't be fooled by its size or cuteness though, one dose of this little critter's venom can kill 26 adult humans. The venom is TTX ( the same found in puffer fish) and works by slowly paralysing your body parts and eventually your lungs. There is an antidote and most people survive being bitten. Blue ring octopuses are not at all aggressive and never attack unprovoked.

Danger level: 8

Stonefish

Stonefish are the most venomous of all fish on earth and even of the ones in their own family, the Scorpaenidae, which regroups Scorpion fish, lion fish and stone fish. They have several poisonous spines on their back and a 'switchblade-like' one called a lacrymal sabre (literally the 'tear sword') that flicks out a cavity contained in the flesh of the bone surrounding the eye. The venom contained in these spines can kill a human if left untreated and is very very painful. Stonefish do not move around much and generally sit on rocky bottoms so the only way to get harmed is to step on them or lay a hand on them.

Danger level: 6

Scorpionfish and Lionfish

These venomous fish are very common companions on the reef. Lionfish swim around mid-water and have long poisonous spines you really do not want to kick when swimming. Scorpionfish, like stonefish, are benthic dwellers for the most part, hanging out on rocky bottoms or camouflaged against the reef. Both have a very painful poison which will not put an adult's life in danger but can provoke convulsions, fever, vomiting, swelling and pretty intense pain. Neither fish actually attack but they are very common species so there is the risk of stepping on them or kicking into them when swimming.

Danger level: 4

Though extremely venomous, the banded sea krait never attacks divers

Sea snake

This frequently encountered marine reptile is a very venomous snake without an ounce of aggressivity. The venom of the sea krait affects both muscles and nerves. It is 10 times more toxic than that of a rattlesnake. If not treated, a host of systemic symptoms and complications that include generalized muscle damage, neurological symptoms, and organ damage (kidney failure) may affect the victim; in the worst cases, death. However, there are very few bites occurrences recorded compared to other venomous species such as cobras and vipers, as it is not aggressive and tends to avoid humans. If they do bite, it is usually in self-defence when accidentally grabbed. Nearly all sea snake bites occur when fishermen attempt to untangle the snakes from their fishing nets, divers do not get bitten.

Danger level: 7

Stingray

Stingrays have a venomous barb at the end of the tail which delivers poison. Stingrays are not aggressive and generally do not attack. When stingrays feel threatened, their reaction is to swim away; however, when they are stepped on or attacked by predators, the barbed spine on the tail is whipped up causing injury to the aggressor. Humans typically get “stung” by this spine by stepping on a stingray that is partially buried in the sand or sediments. The most common stingray in Penida is Kuhl's maskray or blue spotted stingray, found abundantly at Manta Point dive site.

It has two venomous spines on the tail that may cause extremely painful wounds.

Danger level: 5

Barracuda

Barracuda are common in Bali. In Tulamben, a 1.20 m specimen chilled in the shallows for 10 years, In Nusa Penida it is not uncommon for divers to discover a Barracuda using them as cover when on a hunting spree. In Bali, There are no recorded attacks, however, a quick trawl on the internet will reveal a number of attacks, some quite serious. One of our divers also reported an attack in the Caribbean that left him with a huge scar on the back of his head. They are extremely fast and powerful fish with a double line of razor-sharp teeth. It is said that they are attracted to shiny objects like jewelry though many of the attacks we have read about or heard did not involve anything of the kind. When swimming with Barracuda, keep them in your sights and make sure you stay close to your buddy so you can assist each other if needed. Fear not but exercise caution.

Danger level: 5

Lionfish venom can cause very unpleasant symptoms but is not life threatening

Shark

In Bali, shark attacks are unheard of. Even spear fishermen do not report being harassed by them. When you are lucky enough to encounter a shark, chances are the first thing it will do is swim away as fast as possible. On rare occasions, curious reef sharks will hang around for a little but for the most part, sharks in Nusa Penida are shy and fleeting. They are mostly the docile bamboo shark or small white- or black-tip reef sharks.

Danger level: 2 (depending on species)

Cone snail

If you see a beautiful cone-shaped marine snail, it is probably a cone snail. It’s difficult to tell whether a cone snail is inhabiting a given shell, as they are able to hide deep inside them. Since all cone snails are venomous, err on the side of safety, and do not touch it. Injuries typically occur when the animal is handled. Cone snails administer stings by extending a long flexible tube called a proboscis and then firing a venomous, harpoon-like tooth. A cone snail sting can cause mild to moderate pain, and the area may develop other signs of an acute inflammatory reaction such as redness and swelling. Conus toxins affect the nervous system and are capable of causing paralysis, which may lead to respiratory failure and death. There are 11 species of cone snails found in Bali.

Danger level: 5