Some scientists say jellyfish are taking over the world’s oceans, with the help of humans and climate change, threatening other marine life and people. But others say there’s not yet enough evidence that jellyfish are increasing and the dangers are overblown.

CBC’s The Current dove into the scientific controversy by hearing from:

  • Tim Flannery, chief commissioner of the Australian Climate Change Commission. He spoke about how humans are helping jellyfish expand and thrive through such activities as fishing and by changing the climate. Flannery also described some of the more dangerous species that may be spreading, including one that can kill a human in four to six minutes, and one that can make you "vomit once a minute for 24 hours."
  • Steve Haddock, a scientist at the Monterey Bay Aquarium Research Institute in California, who runs the JellyWatch website, where people can report jellyfish sightings. He doesn’t think there’s enough evidence to say jellyfish populations are growing. Nor does he think that climate change is necessarily good for jellyfish. Haddock also thinks it's misleading to use the term "jellyfish invasion" and to talk about jellyfish as a single group.
  • Lucas Brotz, a jellyfish researcher and Ph.D. candidate at the University of British Columbia, who released a study last year on jellyfish populations worldwide. He discussed his findings and talked a bit about why scientists are so divided about jellyfish and whether they're really taking over the oceans.
  • Mackenzie Neil, senior aquarium biologist at the Vancouver Aquarium, who gave a behind-the-scenes tour of the exhibit Jellyfish Invasion.

Listen to the full interviews on The Current.