Myrtle Beach, South Carolina, is a popular destination known for its expansive beaches and warm Atlantic waters. The ocean is home to various marine life, including several species of jellyfish. These creatures, recognizable by their bell-shaped bodies and trailing tentacles, are common visitors to the coast and can occasionally affect beachgoers. Understanding which species are present and what precautions to take is important for safely enjoying the Grand Strand’s aquatic environment.
Common Jellyfish Species of Myrtle Beach
The most frequently encountered species in the Myrtle Beach area is the Cannonball Jellyfish (Stomolophus meleagris), often called the cabbage head jellyfish. This species is easily identified by its firm, dome-shaped bell that can grow up to 10 inches in diameter. Cannonball jellies typically have a white or pale blue bell with a distinct brown or purple band circling the rim below the bell. They are notably abundant near the coast and in estuaries during the warmer months.
Another common sight is the Moon Jellyfish (Aurelia aurita), which appears as a nearly transparent, saucer-shaped bell. These jellies are distinguished by four visible, horseshoe-shaped gonads seen through the top of the bell. They possess hundreds of short, fine tentacles lining the bell margin.
The Atlantic Sea Nettle (Chrysaora quinquecirrha) is also prevalent, particularly during the summer and early fall. It has a saucer-shaped bell, usually tinted red or brown, and features long, noticeable marginal tentacles that can extend several feet.
Beachgoers should also be aware of the Portuguese Man O’ War (Physalia physalis), though it is not a true jellyfish but a siphonophore, a colony of specialized organisms. This creature is identifiable by its purplish-blue, gas-filled float that sits above the water and long, highly venomous tentacles that can reach lengths of up to 30 feet.
Assessing Sting Severity and Risk
The risk to humans varies significantly among the species found off the Myrtle Beach coast. The Cannonball Jellyfish is considered one of the least venomous species in the region, and its sting is generally not felt by humans. Similarly, the Moon Jellyfish sting is mild, often producing only a slight, prickly or mild burning sensation.
In contrast, the Atlantic Sea Nettle is the most common cause of jellyfish stings in South Carolina waters. Contact with a Sea Nettle’s tentacles delivers a painful sting that can cause significant discomfort. The Portuguese Man O’ War poses the highest risk, as its sting is intensely painful. The venom can cause systemic symptoms like intense joint and muscle pain, nausea, and vomiting.
Another species, the Sea Wasp or Box Jelly (Chiropsalmus quadrumanus), is the most venomous true jellyfish in South Carolina waters. Its potent sting can cause severe skin irritation and may necessitate hospitalization. The stinging cells, or nematocysts, on any of these species can still discharge venom and sting a person even after the creature has washed ashore.
Seasonal Appearance and Local Factors
The peak period for many species, including the Cannonball Jellyfish and Atlantic Sea Nettle, is typically during the warmer summer and early fall months. Rising ocean water temperatures create an environment conducive to jellyfish blooms, which are large aggregations of the animals.
The movement of these creatures is largely dictated by forces beyond their control, as they are not strong swimmers. Wind direction and ocean currents play a dominant role in pushing jellyfish close to the shore or stranding them on the beach. Strong onshore winds, particularly following storms offshore, can result in large numbers of jellyfish being deposited along the Grand Strand coastline.
Portuguese Man O’ War sightings are less predictable. They tend to occur when warm currents, such as the Gulf Stream, transport them north from their usual tropical habitats. Local authorities and lifeguard services often monitor conditions and may use beach flags or warning systems to alert the public when large blooms or more hazardous species are being observed in the swimming areas.
Immediate First Aid for Stings
Immediate first aid can help minimize the pain and effects of the venom. Carefully remove any visible tentacles or stinging material using tweezers or a gloved hand, avoiding direct contact with the skin. Rubbing the affected area should be avoided, as this can cause the remaining stinging cells to fire more venom.
Rinse the area with seawater or a saline solution, as fresh water can trigger the release of more venom from the stinging cells. Following the removal of tentacles, soaking the affected area in hot water is the most effective way to denature the venom and provide pain relief. The water should be as hot as the person can tolerate, for at least 20 to 45 minutes.
Applying vinegar to the site for at least 30 seconds can neutralize the stinging cells, though this can be counterproductive for a Man O’ War sting. Medical attention should be sought immediately if the sting is from a Portuguese Man O’ War, covers a large area of the body, or if the individual shows signs of a severe allergic reaction (e.g., difficulty breathing, chest pain, or nausea). The use of unproven remedies like human urine, alcohol, or scraping the stingers should be avoided.