Jellyfish populations in the Mediterranean Sea

Knowledge of jellyfish populations in the Mediterranean Sea is rather extensive, due to a combination of long-term datasets and interest relating to impacts on human activities. The notorious jellyfish Pelagia noctiluca appears to be blooming with increased frequency in some areas, and may sting tens of thousands of sea bathers in a single year. In addition, a number of invasive species of jellyfish appear to be thriving in the Mediterranean, some of which have significant impacts on fishing and other industries. In contrast, other groups of jellyfish show variable trends over time, and may be of little interest to the public. Here, we summarize knowledge of jellyfish in the Mediterranean Sea, including temporal trends for a variety of species, and discuss possible anthropogenic causes of increased jellyfish abundance and management interventions in the face of uncertainty.