The jellyfish-like Portuguese man-of-war has visited Maltese waters in the past and a scientist holds evidence in a glass jar, which contains one caught eight years ago at Golden Bay.

This year, the number of sightings has increased compared to previous years, however there was no cause for concern at this stage, marine biologist Patrick Schembri said, holding the preserved specimen of the man-of-war picked up in 2001.

Technically called physalia physalis, the man-of-war is not actually a jellyfish but a colony of different organisms, including polyps, living together. It is notorious for its painful sting.

Prof. Schembri, a University biology professor, received about three reported sightings of the invertebrate this year and one last year.

Rumours of the presence of the man-of-war in Maltese waters started up earlier this year with the circulation of an e-mail claiming the species had been sighted in local waters.

Given there were no official reports, authorities initially disregarded the e-mail as a rumour even though it was not impossible given that the man-of-war had a wide distribution in warm waters, including the Mediterranean, although it is not known to breed here and nor is it common.

Sometime later, sightings of the man-of-war started trickling in. The Biological Conservation Research Foundation and the health authorities received a few reports, some of which were accompanied by photographs. However, these sightings remained unconfirmed as the authorities had nothing to go by other than the inconclusive images.

Armed with his preserved specimen, Prof. Schembri yesterday proved the invertebrate species had come to Malta.

He said the 2001 specimen was the first he had seen but over the past 25 years he had received a few reports from fishermen claiming they had seen something that looked like a blue plastic bag.

In fact, the man-of-war is sometimes called a bluebottle because of its distinct colour.

The sightings reported to him this year and last were of something about 10 centimetres long with tentacles about a metre long.

"It seems that for some reason they are arriving more frequently despite still in very low numbers and therefore there is no cause for concern at this stage," he said.

The man-of-war cannot move on its own steam and depends on current. Apart from that, it can only live in warm waters. Although not common in the Mediterranean, the species has recently been sighted close to Spain and Italy.

Prof. Schembri believes this may be due to the warming up of the water surface due to global warming. This created a sort of water bridge that allowed the man-of-war to survive as it drifted into the Mediterranean.

He said the purple stinger, the common local jellyfish, was more reason to worry. Unlike the man-of-war, these jellies could actually swim below the surface making them less visible to swimmers as they drift into bays.

For the past decade population blooms, or sudden increases, were common. What was different now was the increased frequency of these blooms. There may be various reasons for this ranging from climate change to pollution and overfishing

Finding a solution was not easy without disrupting the sea's ecological balance. The best way was to gently pick them out of the sea and leave them to dry on shore - without breaking off stinging tentacles that would remain floating in the water.

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