“Every year more jellyfish are seen …” This is one of the most frequent comments among bathers who visit the beaches of our coasts each summer. Theglobal increase in jellyfish populationsit is a fact that worries tourists and intrigues scientists. The increase in water temperature and other aspects related to the biology of jellyfish in their adult life have been some of the variables on which the latest research has focused. Now, a team of scientists led by the Mediterranean Institute for Advanced Studies (University of the Balearic Islands and CSIC) gives a twist and offers another explanation to the problem:the increase in human infrastructuresas ports and oil platforms it favors the proliferation of these animals.
During their life cycle, jellyfish go through the so-called polyp phase, during which they reproduce asexually and lack mobility. According to the results of the research, published in the journalFrontiers in Ecology and the Environment, polyps especially like to nest on artificial surfaces such asports, oil rigs, aquaculture farms and tourist facilities. Specifically, the scientists detected a density of almost 20 polyps per square centimeter of the speciesCotylorhiza tuberculataon the bricks in front of only one of them per square centimeter nested in live oyster shells and approximately eight polyps per square centimeter on dead specimen shells.
Man-made structures in coastal areas are increasing between 3.7% and one
28.3% annually. “This increase is providing habitats for polyps, which could be an important factor in explaining the global increase in jellyfish proliferation,” explained Carlos Duarte, one of the authors. The analyzed regions belong tounderwater areas around the worldThese include Japan, the United Kingdom, Spain, and the United States.
