Jellyfish are “very simple organisms even though they are 500 million years old” and “take advantage of the organic pollution of the oceans as food”, in addition to benefiting from the absence of predators, which helps their proliferation in bathing areas.
This was stated to EFE by the scientific diver and researcher at the European University of the Canary Islands Juan Diego López Arquillo, who also explained that these gelatinous animals, despite being “annoying” due to the toxins transmitted by their tentacles “are more necessary than what we think”.
In fact, “they constitute a food for higher species in the trophic chain” who, by devouring them, regulate their quantity, so another reason for their increase is the “overfishing of their predators”, among which are turtles marine life, crustaceans, corals and various types of fish such as sunfish or sharks.
These cnidarian or coelenterate animals, like the rest of the inhabitants of the seas and oceans, have also suffered the three great changes in their ecosystem: “those of contribution, those of limitation of species and temperatures”.
In this sense, “climate change could be a decisive factor for their growth” because, although “it is not possible to know exactly why they reach some coasts more than others” it has been proven that, if the temperature of the water increases, the the following year “jellyfish have an easier time reproducing” in the same area.
López Arquillo has also referred to the “many myths that surround them” and cites, for example, the fact that the Portuguese man-of-war is presented as a jellyfish when “it is not, but rather a hydrozoan that belongs to the same class.”
In addition, for the collective imagination, jellyfish only proliferate in warm or hot waters, but this is not correct either: they live better in higher temperatures and that is why they are seen more on the Mediterranean coast, but there are species such as “Pelagia noctiluca” or jellyfish carnation so adapted to the cold that “it is frequently found in the Atlantic and the Cantabrian Sea”.
“Even in the coldest waters of the Antarctic we can find cnidarians like corals”, recalls this specialist, who lists the most common species on the Spanish coast: “Stomolophus meleagris” or cannon ball, “Cotylorhiza tuberculata” or fried egg and “Rhizostoma pulmo” or aguamala.
Another inaccurate information is that jellyfish sting, but “they don’t actually do it, rather you are the one who suffers the sting by touching the stinging cells” of their tentacles, known as cnidocytes and useful for hunting their prey.
In case of contact with them, the affected area should not be washed with fresh water but “clean the irritated skin with salt water, so that no trace remains” of its toxins and later “use creams with corticosteroids if necessary” to deal with the inflammation.
The danger of these irritations has a lot to do not only with the stinging capacity of each species but also with the reaction of the body of each affected individual.
Thus, the “Chironex fleckeri” or sea wasp is a deadly jellyfish and also one of the deadliest animals on the entire planet, although López Arquillo recommends not worrying too much about its presence since “it usually lives on the coasts of Australia” .
Although the first impulse of some bathers when discovering jellyfish in the water is to get them out of there and let them die on the sand, these specialists affirm that this “is an act of ignorance”, when “we simply have to be extremely careful or not get into the sea Because after all that is your home.