February 20th, 2022 - The barrel jellyfish is mostly harmless to humans, but sure seems to be a menace to fishing nets due to its size - and numbers. Fishermen have been struggling with an invasion of huge jellyfish in the north of Istria that shows no sign of subsiding

An infestation of large jellyfish has been a source of headache for fishermen in Umag and Savudrija for two months now, so much so that some have given up and are not even going out to sea anymore. There are so many of them, and they’re so big and heavy that they destroy the nets as the fishermen lift them out of the sea, reports Jutarnji list.

Danilo Latin, a fisherman from Savudrija, says it’s not uncommon for them to pull out one ton of jellyfish at a time. He’s never seen such a thing before, and fishermen in general don’t know how to go about it. 

‘This has been going on for two months. It’s never been this way. Last year, [the jellyfish] appeared for a short while in March and that was that. This year they just won’t leave, and we don’t know when we’ll be able to go out to sea again. There are so many of them that even us fishermen are starting to feel uneasy. A friend of mine was recently at sea and told me that he’s never been scared to look at the sea before. He had a feeling as if it were ghosts under the surface’, said Latin.

Latin and other fishermen who are dealing with the jellyfish invasion in northern Istria are calling for the situation to be declared a natural disaster.

‘We can’t go out to sea as we only suffer damage. Some of the jellyfish weigh up to eight kilograms. And we don’t even know when we’ll be able to sail out. We informed experts at the Institute of Agriculture and Tourism in Poreč of this, and invited the Ruđer Bošković Centre for Marine Research in Rovinj as we wish for this to be declared a natural disaster. As far as I know, the scientists from the Rovinj institute haven’t yet arrived to see what’s going on. We reached out to the Department of Agriculture of Istria County and they told us they had never dealt with this issue. It’s new to everyone’, Latin said, adding it wasn’t only an issue in Umag and Savudrija, but also in the waters of Slovenia and the Italian region Friuli Venezia Giulia.

Scientist Barbara Sladonja from the Centre for Invasive Species of the Institute of Agriculture and Tourism in Poreč wasn’t able to say with certainty when the jellyfish would pull back and if it would happen before summer.

‘It’s the barrel jellyfish (Lat. Rhizostoma pulmo). This jellyfish is naturally found in our waters, and over the last hundred years or so, it has made an occasional appearance in large numbers. It’s the so-called jellyfish bloom phenomenon, seen in many jellyfish species, including the barrel jellyfish. In recent years, such blooms have been lasting longer and longer. It can’t be said for sure when it will pull back. Judging by the last few years, they already should have retreated, but their population remains large. We hope this won’t last until summer’, said the scientist.

She explained there were several reasons why the jellyfish would appear in such large numbers.

‘One reason is the sea temperature being too high. The barrel jellyfish population should decrease significantly in winter due to low temperatures. This year, it apparently hasn’t dropped low enough, and the population kept growing. In addition, marine food chains have been disrupted by several factors’, said Sladonja.

Experts from the Ruđer Bošković Institute from Rovinj said they were monitoring the phenomenon and that this jellyfish species is among the bigger ones found in the Adriatic. They can weigh up to 10 kilos each.

Until they fall back, it’s only the Ministry of the Sea that can help the fishermen. According to Ezio Pinzan, head of Istria’s Department of Agriculture, Istria County doesn’t have the funds for it.

‘We have to see what’s going on and how to prevent it from happening again next year. The Ministry has an aid package of 50 million kuna in the works, which they’ll distribute to our fishermen for this difficult situation’, said Pinzan.

June the 14th, 2021 - A warning has been issued to swimmers in the southern Istrian part of the Adriatic after Croatian divers stumbled upon a dangerous type of jellyfish.

When swimming in the calm and peaceful Croatian Adriatic, it's difficult to imagine that anything could be lurking down in the depths where you can't see. The crystal clear waters allow for a view of all of the fish and other marine creatures living down below, but rarely do we imagine coming to some harm.

Although sharks do live in the Croatian Adriatic, they pose little to no threat and much prefer to avoid any contant with humans, making being able to see and film them a delight rather than the cause of a panic attack. The most common injury caused by a resident of the Adriatic is one by a sea urchin, who can pack a punch with its spikes when accidentally stepped on.

Jellyfish, however, are quite another story indeed, and a recent discovery is of a type which does more than deliver an uncomfortable but generally harmless sting.

As Poslovni Dnevnik writes, Croatian divers spotted the dangerous jellyfish (Pelagia noctiluca) on Sunday in the south of Istria. Being stung by this jellyfish causes severe pain, and upon contact with human skin, the creature causes agonising injuries similar to burns that are then very difficult to heal.

This jellyfish, which has numerous names - the mauve stinger, the purple-striped jelly, the purple stinger, the purple people eater, the purple jellyfish, the luminous jellyfish and the night-light jellyfish, is a relatively small creature with a semicircular head and pink tentacles, sprinkled with tiny purple dots.

As stated, upon contact with human skin, severe pain occurs and injuries similar to burns appear, which are difficult to heal, followed by depigmentation of the skin and even deep scarring, local portal Glas Istre writes.

This jellyfish was spotted by the Croatian divers on Sunday in the bay of Velika Kolumbarica near the Kamenjak peninsula. Sea currents and waves sometimes carry these jellyfish to the shore, where they'd prefer not to be, and where they become a threat to swimmers.

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