The Spot the Jellyfish campaign said today that it had received numerous reports over the past few days of sightings of the box jellyfish species – Carybdea marsupialis – in the yacht marinas at Ta' Xbiex/Msida and Vittoriosa.

In all cases, the box jellyfish were reported as occurring in groups of less than five.

Marine biologist Dr. Alan Deidun, coordinator of the campaign, said the jellyfish might have a preference for concrete walls or for nutrient-rich (polluted waters), or it might be that its larval stages are being transported by recreational vessels.

The species has a roughly conical umbrella shape, with four long tentacles emerging from each corner of the umbrella and having roughly 4-5 times the length of the umbrella which is normally only 3cm long. The species is highly transparent and quite difficult to spot in water, normally occurring at great depths (500-1000 meters) but which can be occasionally nudged to the surface by currents. Although not lethal as its Pacific Ocean counterpart – the sea wasp (Chironex fleckeri) – which is listed as one of the most venomous animal species on earth, the Mediterranean box jellyfish species can still inflict painful stings.

The Spot the Jellyfish initiative website (www.ioikids.net/jellyfish) now gives users the possibility to search the total number of jellyfish sightings for each bay on an annual basis, from 2010 to 2012. From such statistics, it transpires that a total of 384, 118 and 205 reports were submitted by the public to the initiative's database in 2010, 2011 and 2012 respectively.

The initiative is coordinated by Dr. Alan Deidun, Prof. Aldo Drago and staff of IOI-MOC, and enjoys the support of the Malta Tourism Authority (MTA) and of Nature Trust, Friends of the Earth, EkoSkola, the BlueFlag Malta programme and Sharklab. (http://www.scienceforcitizens.net/blog/2010/08/spot-the-jellyfish-here-or-in-malta/)