An Australian teen was recently hospitalised after a mysterious swarm of creatures seemed to bite his legs and cause serious bleeding. While the incident has produced some shock and awe, there’s no reason to get too worked up about it.
Photo by Gaute H.
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Sea Lice Are Not to Blame
yikes! Australian teen comes out of the ocean pouring blood. attacked by some tiny creatures. maybe sea lice?? https://t.co/VcF4DGPMha
— Peter Krupa ? (@peterkrupa) August 7, 2017
They feed on mucus, epidermal tissue, and are literal bloodsuckers, but they rarely attempt to feed on people. Video of the creatures in question was soon put online by the victim’s father, showing the tiny monsters devouring chunks of raw meat. It’s pretty gross:
Frightening indeed, but the Museums Victoria, located in Carlton, Victoria, quickly identified the creatures as lysianassid amphipods or “sea fleas”, a type of scavenging crustacean — not sea lice. According to marine biologist Genefor Walker-Smith, who examined a sample collected by the teen’s father, sea fleas have bitten people before, but this type of attack is unusual:
It was just unlucky. It’s possible he disturbed a feeding group but they are generally not out there waiting to attack like piranhas.
Alistair Poore, a University of New South Wales associate professor, told The New York Times that there may have been greater numbers of them in the area than normal — perhaps caused by a large number of dead fish in the area. And Poore goes on to say that these animals are no different than the leeches and mosquitoes you’d find on land. They’re not fun, but they aren’t exactly life-threatening either.
This Was a Particularly Rare Incident
So why was does this case of sea flea bites seem so extreme? Walker-Smith suggests a few possibilities. First, the teen may have unknowingly stepped on or near a fish carcass where a swarm of fleas was already in feeding frenzy mode. Second, the water was very cold so the teen probably couldn’t feel the bites as they occurred. Lastly, the amphipods may have employed an anti-coagulant similar to the way leeches feed, causing a great deal of blood to flow.
The teen told the press that he was just trying to soak his sore legs for a half-hour or so in Dendy Street’s Beach in Brighton after a football match. Walker-Smith says it’s possible the teen had injuries or small cuts on his legs that drew the scavenging fleas to him initially, and the more they bit the more they caused him to bleed, drawing more in on the feast. Marine biologist Michael Keough, from the University of Melbourne, explained the process to The Age:
They’re scavengers who’ll clean up dead fish and feed on living tissue… if he’s been standing around for a long time, it’s the chance for more of them to come in and start biting. Just be attracted to a little bit of blood. And if he’s standing in the water and he’s cold and may not notice a whole lot of little bites.
In truth, you’re more likely to encounter “swimmer’s itch”, also known as cercarial dermatitis, which is a harmless skin rash caused by microscopic water parasites and their larvae. The larvae burrow into your skin, causing an allergic reaction, then die because you aren’t a suitable host. It sounds a lot scarier than it is. And most of the “bites”, or “sea bather’s eruptions”, you think you get from sea lice or sea fleas are probably actually caused by jellyfish larvae.
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Avoiding Sea Flea Bites Is Easy
Sea fleas are in every ocean all over the planet and number in the hundreds of millions, so you can’t really avoid them entirely if you want to go swimming at the beach. That said, there are a few things you can do to greatly reduce your chance of being bitten:
- Swim during the daytime: Walker-Smith says they’re more active at night and dusk to avoid predators.
- Watch where you put your feet: Sea fleas want to eat dead fish, not your feet. But if you put your feet right next to a dead fish, they will get confused and go for your flesh instead. Hey, a meal’s a meal. Just pay attention to where you’re walking and swimming, especially if the water is cold and you can’t feel your skin.
- Keep moving: They may not be able to cling on to you if you keep moving through the water, so don’t stand still for too long in one place.
- Don’t bleed in the water: Blood in water attracts predators and anything that feeds on blood. So, uh, don’t go in the water with an open wound. Also, there’s bacteria in the water, so there’s another reason you shouldn’t do this. I feel like you should know this already, but just in case…
Remember, these little guys are mostly harmless, and most of the experts weighing in on the event say there’s no reason to avoid going in the water. For most people, sea fleas are nothing but an annoyance. Think of them as “sea mosquitoes”, not teeny-tiny piranhas. They’re not venomous, rarely this voracious, and this incident was simply a case of being in the wrong place at the wrong time. Also, they’re a vital part of the marine environment. Walker-Smith explains that “…if we didn’t have them we would have a sea filled with dead and decaying fish”. Yuck — that sounds much worse to me.
This is part of Lifehacker’s new Never Fear series. The world is a scary place, but we tend to misplace our fear in things that don’t really deserve our precious time and energy. Let’s fight those fears together with a little knowledge.