Jellyfish explosion may be natural cycle
Evidence that jellyfish are taking over the oceans is currently lacking, according to a new study published in Bioscience. Complied by a number of marine experts, the study found that while jellyfish have been on the rise in some regions it is likely due to a natural cycle of jellyfish populations and not a global boom. Researchers, including a number of marine biologists, have warned for years that jellyfish numbers may be exploding due to human activities, such as overfishing, warmer oceans due to global climate change, and the rise of oxygen-depleted, so-called "dead zones."
"Clearly, there are areas where jellyfish have increased—the situation with the Giant Jellyfish in Japan is a classic example," says lead author Rob Condon, marine scientist at the Dauphin Island Sea Lab (DISL) in the U.S. "But there are also areas where jellyfish have decreased, or fluctuate over the decadal periods."
Looking over data going back to 1790, researchers did not see any long-term upswing in jellyfish populations, but rather boom-and-bust cycles that have been occurring for centuries.
Jelly fish photo via Shutterstock