Dangerous jellyfish in the Baltic Sea? These species can be found near the shore

Contact with a jellyfish living in the Baltic Sea is not always dangerous to humans. Of the two species found in our sea, only one, the lion’s mane jellyfish, causes painful stings. The more commonly seen moon jelly, which resembles a blob of jelly, has venom that is harmless to humans. The two Baltic jellyfish species are quite easy to tell apart.

What jellyfish live in the Baltic Sea?

Two species of jellyfish can be found in the Baltic Sea: the moon jelly (Aurelia aurita) and the lion’s mane jellyfish (Cyanea capillata). They differ not only in appearance but also in their habits and preferred habitat. The moon jelly is often seen close to the shore. It prefers warmer water and lives near the surface. The lion’s mane jellyfish is different. This species prefers deeper waters. However, that does not mean it never reaches the beach. Individuals are sometimes carried ashore by sea currents.

How to identify the common Baltic jellyfish species: the moon jelly and the lion’s mane jellyfish

The two species are easy to distinguish. The moon jelly is often described as looking like “jelly.” Its transparent body is made up of 98 percent water. At the center, around the mouth opening, are four symmetrically arranged oral arms equipped with stinging cells. The sexes can also be distinguished by color: males have purple reproductive organs, while females have blue ones.

The lion’s mane jellyfish is the largest jellyfish species in the world. Specimens living in the Baltic Sea can reach up to 50 cm in diameter. They vary in color, ranging from yellow and pink to light blue. Long, hair-like tentacles hang from the bell, usually arranged in eight clusters.

Which Baltic jellyfish can sting humans?

Both the moon jelly and the lion’s mane jellyfish have stinging cells containing venom. Physical contact with a moon jelly does not pose a threat to humans. The lion’s mane jellyfish, however, can cause painful stings.

When swimming in the Baltic Sea or relaxing on the beach, you should also watch out for dead jellyfish. Even then, touching them can result in a sting.

What to do after a jellyfish sting

To prevent the venom from causing further damage, gently rinse the affected area with seawater. This helps prevent additional venom from being released. You can also try to remove any stinging cells attached to the skin using tweezers or the edge of a plastic bank card (or a similar object). Do not rub the skin vigorously, as this will intensify the effects of the venom. To relieve pain, cover the affected area with a warm compress or immerse it in warm water for about 20 to 45 minutes.

Why should you avoid fresh water after a jellyfish sting? Rinsing the affected area with fresh water, whether from a bottle or a tap, is dangerous because it causes the attached stinging cells to rupture, releasing additional venom and resulting in more severe stings. You should also never disinfect the wound with alcohol or urine. This is a common but false myth.

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main photo: Alexander Vasenin/Wikipedia