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1,000s Of Dead Jellyfish Wash Up On Hilton Head’s (Nearly) Empty Beaches. What’s Going On?
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Hilton Head’s beaches are eerily empty right now and cluttered with dead jellyfish.
Thats right, thousands of dead jellyfish littered Hilton Head’s north end beaches on Friday.
On Friday, the beaches were bizarre and bare. I kept a solid 25-foot distance from the few people I saw and made sure I didn’t touch anything.
But on Friday, everything about the beach felt out of place. The tide was abnormally low. The waves were feeble — almost nonexistent as if the ocean just wasn’t pushing anymore. And then, I looked at the ground.
Thousands of light brown cannonball jellyfish cluttered the beach from the shore to the tideline for miles up the coast.
The sight can be disturbing and baffling — especially with all those dead creatures laying on nearly deserted beaches.
But I’ve actually seen this — and written about it quite extensively — in the springtime before here on Hilton Head.
So what’s causing these jellyfish graveyards?
As the Post and Courier’s Bo Peterson explained: It’s those summer breezes causing the dead jellyfish clutters.
“Cannonball jellies tend to turn up in the nearshore waters during April, pushed in from the Gulf Stream with washes of warmer water,” Peterson wrote last spring. “They’re a sign that the surf is approaching that magic room-temperature zone a lot of people find plungeable on a hot day.”
But there’s a little more to it.
So jellyfish tend to travel in large blooms, and sometimes rough winds, swells and currents can knock hundreds of them out at once and send them all to shore in a sweep —making for quite the jellyfish graveyard.
“They often get pushed to shore as a group,” Blaine Griffen, a marine biologist at the University of South Carolina, previously told (me at) The Island Packet. “Sometimes, it’s the current, and some of them are just killed by annual population cycles.”
Sea Pines in late April, 2019
Also — it’s jellyfish blooming season in the Atlantic, the Marine Biology Association of the UK previously explained to us on Twitter. “If you’ve had onshore winds in the last few days, swarms of jellies can wash up.”
So jellyfish are really bad swimmers. They’re cold-blooded animals and can lose mobility when water temperatures are below normal. Because jellies are mostly made of water, so they die quickly after washing up on shore.
Most of these jellyfish washing up on the shore are cannonball jelly, which rarely sting while alive and if they do, the sting likely can’t be felt by a human. Cannonball jellyfish look like clear mushrooms with a brown border. They lose their color when they die and can’t hurt humans.
However, some jellyfish can sting you even after they die, so be cautious about touching any dead ones.
The Portuguese Man-of-War, which actually isn’t a jellyfish but a colony of organisms, can still sting humans after they die. Man-of-war jellies are sack-like creatures with bright blue and purple tentacles. They aren’t extremely common, but are sighted on South Carolina beaches every year.
Portuguese man-of-war, Getty Photo
What happens to all those dead jellies?
Because Friday’s tides were abnormally low in the afternoon, high tide likely swept away a lot of these rubbery creatures hours after I left.
Birds and crabs and other scavengers on the beach will eat up those jellies in no time.
One of South Carolina’s favorite marine animals — the sea turtle — loves to snack on jellyfish. Particularly leatherback sea turtles love to eat jellyfish. Sadly these creatures often confuse plastic bags with jellyfish.
The cannonball jellyfish(Stomolophus meleagris), also known as the cabbagehead jellyfish, is a species of jellyfish in the family Stomolophidae. Its common name derives from its similarity to a cannonball in shape and size. Its dome-shaped bell can reach 25 cm (10 in) in diameter. The rim is often colored with brown pigment. There are several known undescribed Stomolophus species found in the Pacific and South Atlantic that exhibit pale to blue pigment. They are genetically different from the individuals found in the North Atlantic - but are commonly misidentified as such. Underneath the body is a cluster of oral arms that extend out around the mouth. These arms function in propulsion and as an aid in catching prey.[2]Cannonballs are prominent from North America's eastern seaboard to the Gulf of Mexico.
Toxin
When disrupted, the cannonball secretes a mucus out of its nematocyst that contains a toxin. The toxin harms small fish in the immediate area, and drives away most predators, except for certain types of crabs. Although cannonballs do not commonly sting humans, they do have toxins which can, but not usually, cause cardiac problems in animals and humans. The toxin can cause irregular heart rhythms and problems in the myocardialconduction pathways. Such complications are associated also with toxins of other cnidaria. The toxin is also harmful to the eyes; contact with a nematocyst can be very painful, followed by redness and swelling. However, cannonball jellyfish are mostly harmless to humans. Contact with them may cause the skin to itch slightly, or minor eye irritation. As such they are among the most common causes of minor stings to humans in US and Caribbean waters.
Commercial fishing
Cannonball jellyfish (or "Georgia jellyballs" as they are known locally) are dried, preserved and packaged before being sold to a seafood distributor that ships them to Japan, China and Thailand.
Along the coast of the southern U.S. state of Georgia, jellyfish are a valuable export, which end up on dining tables across Asia. The jellyfish are dried, preserved and packaged before being sold to a seafood distributor that ships them to Japan, China, and Thailand.
Jellyball (as they are known locally) fishing is Georgia’s third largest commercial fishery.[12] In Georgia, fishermen target jellyfish with modified trawl nets, and studies have shown low quantities of bycatch are typically seen in the fishery.[13]
Recently, Mexican coasts have experienced an increase in the abundance and frequency in blooms of this jellyfish. In 2012 El Golfo de Santa Clara harvested 20,000 tons (~$3.5 million USD) from late April to early July, which elevated the importance of this resource in the region. However, further studies need to be done in order to increase the predictability and improve the management strategies.
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