A mauve stinger jellyfish bloom has been reported to the Spot the Jellyfish team over the past few days along several stretches of the northern coast of Malta and Gozo.

The bloom consists of thousands of mature mauve stinger (Pelagia noctiluca) individuals. Blooms for this species are typical for this time of year in the Central Mediterranean, normally commencing towards late autumn in the warmer waters off north Africa, making their appearance further north in Maltese waters towards mid-winter (late January and early February).

At this time of year, in fact, mature mauve stinger individuals rise to shallow waters to reproduce, before dying en masse.

The mauve stinger has been observed in the Mediterranean at least since 1785, but outbreaks of the species have become more frequent only since 1999.

Until 1998, Pelagia blooms occurred every 12 years and had an average duration of four years – since they, they have become more common, presumably as a result of climate change, overfishing and coastal urbanisation and discharges. Abnormally-large mauve stingers, having a diameter exceeding 15cm in many cases, were witnessed at this time last year.

A recent study, conducted in the Straits of Messina, has concluded that increasing sea temperatures in the Mediterranean will result invariably in more frequent blooming events for the species in future.

The Spot the Jellyfish campaign was launched in 2010 by the IOI-Malta Operational Centre based at the University of Malta.

www.ioikids.net/jellyfish   ioi-moc@um.edu.mt