Antoni Grau, the regional director-general of fisheries and the marine environment, says that it is unclear why there were fewer jellyfish than normal over the summer. The 'Pelagia noctiluca' species is the one that causes most bother, but there haven't been many this year. "We don't know why. This species lives in the high seas. Reaching the coast depends on meteorological phenomena, such as storms."
Since 2014, the directorate has operated a system of jellyfish observation in order to calculate numbers. This involves a combination of marine reserve surveillance, lifeguards and the boats which collect waste from the sea. Grau acknowledges that this system has lacked one element this year. For Covid reasons, the boats haven't been operating. Nevertheless, the surveillance in marine reserves has detected very little presence of jellyfish.
The system carries out some 30,000 observations annually. The greatest concentrations of jellyfish have tended to be in areas of the Tramuntana coast. Grau notes that there are particularly high numbers of stings at Banyalbufar and Estellencs beaches.
"We started counting the population in 2014, and in 2018 there was a great abundance. But we can't predict whether there will be more jellyfish." However, the agriculture, fisheries and food ministry is now working with two marine science bodies in developing a mathematical model for predicting numbers.
Grau explains that there are twelve species which are common to Balearic waters. The 'Cotylorhiza tuberculata', known as the fried egg jellyfish, usually arrives at this time of the year. Climate change has increased the number of species, one of which is the Portuguese man o' war. It is increasingly present in the Balearics.