Jellyfish have become the deep-sea monsters of the climate change era, embodying our fears that the warming oceans will spawn increasingly massive swarms of a sinister faceless alien. The reality, though, is that we know next to nothing about these creatures.
We think we know a bit about them: Their sting can kill you. They erupt in blooms that reach 1,000 square miles. They can grow to a length of 120 feet. These are traits, though, of different members of a widely varied species, not simply “jellyfish.”
The need for solid data compelled Monterey Aquarium researcher Steve Haddock to develop Jellywatch, a website and smartphone app designed to enable non-scientists to document the presence of jellyfish anywhere.
In the three years since the app's launch, data has flooded in from all the world’s oceans. Even with satellites, drones, and submersibles, said Haddock, the human eye is still the best tool for collecting the data needed to understand the life cycles of jellyfish populations.
Let’s say you’re taking your early morning stroll down the beach, and you stumble on a gigantic transparent blob in the wet sand. Or you’re a surfer or fisher who frequents the same spots year after year, coming into regular contact with jellies. Participating in science in a substantive way is as simple as uploading a photo with the Jellywatch app, which in turn automatically pulls in your latitude, longitude, time, and other key variables. “Citizen science is the only way to get that distributed coverage that we need,” said Haddock.
Jellywatch is about to get a big boost from the global Jellyfish Database Initiative, which will put all existing data—from centuries-old ship logs to an upload by a beachcomber—in one place. The database, which goes live next month, will be available for anyone to use, whether they're scientists or vacationers heading to the shore with their kids.
“Even the ancient Minoans painted jellyfish on their pottery to the point that you could identify the species,” said Robert Condon, who runs JeDI. “What we have is lots of qualitative information but not much quantitative. We need to have a rigorous baseline, and that’s the reason behind JeDI.”
One question that remains unsolved is whether climate change and ocean warming will prompt a proliferation of jellyfish at the expense of other marine life.
“I haven’t seen anything that does a good job of linking temperature to these populations,” said Haddock. “We’ll need a lot of data to be able to answer that question.”
Scientists know that one species of jellies—the brown sea nettles that are often found on the shore—are a critical food source for the sea turtles that migrate annually from Indonesia to North America. “But the role of jellyfish in the oceans is still largely unknown, and jellyfish research is still relatively recent,” said Condon. He estimates that current data covers roughly half the world’s oceans.
“Jellies have always been there,” said Haddock. “They closed fisheries way back in the 1800s in Denmark because jellies clogged their nets. We’re the ones invading their habitat, not the other way around.”
This post has been revised to reflect the following correction: An earlier version of this article misstated the date and country that closed its fisheries due to jellyfish. It was in the 1800s in Denmark.