Drastic drop in jellyfish sightings in September

The Spot the Jellyfish initiative at the University of Malta said two major conclusions may be inferred from the drop. “Namely, fewer jellyfish individuals were actually present and observed in coastal waters and that bathing intensity declined during September,” biologist Alan Deidun said.

The species observed during this month were four – the ubiquitous mauve stinger (Pelagia noctiluca – a powerful stinger), which was consistently reported since March, the fried egg jellyfish (Cotylorhiza tuberculata – a non-stinger) which was recorded in much smaller abundances than last year, the cigar jellyfish (Olindias phosphorica – a very mild stinger) which was recorded just from Ghadira and St. Thomas Bay, and a proliferation of small pyrosomes in the water column which could have possibly bloomed as a result of terrestrial runoff into the sea after the September heavy downpours.

Pyrosomes are pelagic tunicates which are amongst the fastest known marine growers. Most reported jellyfish blooms worldwide in recent times have occurred in heavily populated areas surrounding semi-enclosed water bodies, with most Mediterranean coastal areas fitting such a bill.

The Spot the Jellyfish initiative is coordinated by Prof. Aldo Drago with the technical and scientific implementation of Dr. Alan Deidun and staff of IOI-MOC, andenjoys the support of the Malta Tourism Authority (MTA) and of Nature Trust, Friends of the Earth, EkoSkola and the BlueFlag Malta programme. A leaflet, downloadable atwww.ioikids.net/jellyfish, is replete with snippets and anecdotes about different jellyfish species. With the support of MTA, large posters have furthermore been projected on boards along major bays on both islands.

Reporting is done by simply matching the sighted jellyfish with a simple visual identification guide, giving the date and time of the sighting, and indicating the number of jellies seen. Sightings can be also reported online or submitted through an SMS on 79 222 278, or by sending an email message to [email protected].

Strange jellyfish not included on the leaflet should be caught and kept in a bucketful of seawater prior to contacting IOI-MOC staff ([email protected]) for retrieval to attempt a definite identification of the species. If this is not possible, photos of the same individuals should be taken.

So far, over three hundred and sixty reports of different jellyfish species have been submitted by the public, and can be viewed online on a summary map (http://193.188.45.233/jellyfish/stats.html) which depicts jellyfish occurrence and distribution. The initiative will ensue during the winter months.