Are Jellyfish Taking Over the World’s Oceans?


Written by Jaymi Heimbuch

The uptake in jellyfish numbers has been in the news a lot the last few years. Indeed just last year massive jellyfish blooms were the reason nuclear power plants in the UK had to shut down, as the little buggers clogged up water intakes used for cooling. Overfishing and climate change have been blamed, as predators of jellyfish are taken from the sea and changes in ocean temperatures and pH balance provide great environments for jellyfish to flourish. But a group of scientists say the drama revolving around “jellyfish taking over the ocean” could be a bunch of bunk.

PhysOrg reports that a study by experts from the Global Jellyfish Group, including Dr. Cathy Lucas, a marine biologist at the University of Southampton, say that the surges in jellyfish numbers are a completely normal part of the species’ history. Yes, we’re experiencing some significant blooms, but the notion that they’re going to take over the oceans in the future is not based on hard evidence, and it sparked interest in the group conducting a thorough study.

The study highlights the centrepiece of their research collaboration with NCEAS the formation of a global database called the Jellyfish Database Initiative (JEDI) a community-based database project that is being used in the global analysis and to test the worthiness of the current paradigm. The database consists of over 500,000 data points about global jellyfish populations collected from as early as 1750, and will be made as a future repository for datasets so that the issue of jellyfish blooms can be continually monitored in the future.

By analysing JEDI, the group will be able to assess key aspects behind the paradigm including whether current jellyfish blooms are caused by human-made actions or whether we are simply more aware of them due to their impact on human activities, such as over-harvesting of fish and increased tourism.

“This is the first time an undertaking of this size on the global scale has been attempted but it is important to know whether jellyfish blooms are human-induced or arise from natural circumstances,” says Dr. Robert H. Condon of Dauphin Island Sea Lab. “The more we know, the better we can manage oceanic ecosystems or respond accurately to future effects of climate change. The scientific data exists to answer this question, but it is fragmented in analysis”.

Science Daily reports that Dr. Condon and his colleagues think that the perception is based on a lack of information about past blooms, more attention being paid to current blooms, and of course “media fascination” with an uptake in blooms. However, they still acknowledge that changes in jellyfish populations do have serious impacts on other sealife and could indeed be impacted by human activity. But they want to gather significant scientific evidence before drawing hard conclusions about the future of our ocean.

This post was originally published by TreeHugger.


Related Stories:

10 Marine Species on the Brink of Mass Extinction Due to Ocean Acidification

10 Deadliest Animals You Wouldn’t Want to Meet

New Year’s Resolution 2012: Let’s Gain Weight in the Ocean


Photo from Shayne Kaye via flickr


Nickihermes Celine
Past Member 4 years ago

thank you for the interesting article,11/7

John Ditchman
John Ditchman4 years ago

Millions of years ago, jellyfish were the most highly developed life form on the planet. Then, things changed and jellyfish became less dominant. If you could talk to a jellyfish, they would tell you how their benevolent, loving god created human to change the oceans back to favoring jellyfish.

greenplanet e.
greenplanet e4 years ago

Due to overfishing and climate change, jellyfish might be the only things left in the oceans.

a             y m.
g d c4 years ago


Melissa L.
Melissa L4 years ago

Interesting, good article!

Cheyenne Thunderbird

This is very much possible because of the state of the oceans are so bad because of the human underdoing and human pollution that the more advanced animal species extinct one by one.

JC Henderson4 years ago

"massive jellyfish blooms were the reason nuclear power plants in the UK had to shut down"

What species of jellyfish were these? Perhaps Jellyae environmentalistae lol

Funny how a humble creature such as this accomplished what environmentalists could not. Now, if we could just get them to go after the whalers ^.^

Kathy Perez
Kathy Johnson5 years ago

im not sure.. if it caused by us then it is bad. if not it could just be a "nature's way" kind of thing....

Karen Baker
Karen Baker5 years ago

Good article thanks

Debbie L.
Debbie Lim5 years ago

Thanks for the article.