Distribution of jellyfish time-series. Time-series of observations on jellyfish abundance >10 y in length from 1874 to 2011. The diameter of the symbols
is proportional to the duration of the dataset, colors indicate trends (linear regressions, P < 0.05): significant decrease (blue), significant increase (red), or no
trend (gray) in jellyfish abundance over time for the duration of the study. Numbers identify the datasets described in Table S1. Most datasets were from the
northern hemisphere (87%), in particular the Atlantic Ocean (17%) and the Mediterranean region (17%), and comprised medusae (89%).