Jellyfish, gelatinous marine animals, are free-swimming in the Mediterranean and usually non-aggressive. But jellyfish reproduction has increased in recent years due to over-fishing and climate change. When the sea warms up (usually in April) or starts to cool down (usually in September) you can see large swarms of jellyfish across the coast and in the bays.
Summer is also considered a high jellyfish season. The most common jellyfish in Malta is the Mauve Stingers, which are usually found near the surface of the water during times of diminished light or after washing up on the beach. They aren’t deadly but their stings do pack a punch. They’re harder to spot when they float solo. Therefore, you may not notice it but only feel a sting. One more species of jellyfish was recorded around Malta is the so-called Australian spotted jellyfish which can inflict a very mild sting when one comes in contact with it.
A purple flag on a beach indicates the possibility of jellyfish. To avoid jellyfish, pay attention to the direction of the wind since they move with the current. Or simply look for information about areas free of jellyfish and safe to swim in.