They found increasing jellyfish populations in 62 percent of the regions studied, including East Asia, the Black Sea, the Mediterranean, the northeast U.S. coastal waters, Hawaii and Antarctica.
They were also found to be decreasing in abundance in seven percent of coastal regions studied.
Jellyfish have become a greater nuisance to human activities in recent years as they clog intakes of power plants, overwhelm fishing nets and sting swimmers.
“We can also see that the places where we see rising numbers of jellyfish are often areas heavily impacted by humans through pollution, overfishing, and warming waters,” said co-author Daniel Pauly, writing in the journal Hydrobiologia.
Photo: Shin-ichi Uye