Changing Planet

Jellyfish Blooms Make Seawater Bubbly

Everyone, from scientists to beachcombers, believe that jellyfish blooms have become more frequent. A new study by Robert Condon of the Virginia Institute of Marine Science and collaborators found that jellyfish blooms can wreak havoc by disrupting ocean food webs – and indirectly adding carbon dioxide to seawater.

Jellyfish eat the tiny plankton at the base of the ocean food chain. By doing so in large volumes, they can reduce the amount of food that goes up the food chain to feed larger animals. Because few animals are able to eat such massive amounts of jellyfish, this may mean a dead-end for food going up the food chain.

What the new research found is that jellyfish release organic matter that dissolves in seawater. In other words, jellyfish “sweat” large amounts of carbon to the water surrounding them. This dissolved carbon is then used by a rare type of marine bacteria, that turns it into carbon dioxide. So there you have it: jellyfish add carbon dioxide to seawater – eventually turning the ocean more acidic.

How big an impact will this have on the global ocean? It’s difficult to know how much will jellyfish blooms trim ocean food webs or contribute to make the ocean more acidic, because we don’t know how frequent and large jellyfish blooms are in the open ocean. However, we do know that jellyfish blooms are becoming more frequent in coastal waters.

What is the solution? Because the cause of the blooms is probably due to a combination of factors (such as organic pollution, climate change, and overfishing), there’s no silver bullet that’s going to fix the problem from one summer to the next. Just be careful on the beach and don’t let them sting you.

Marine ecologist Dr. Enric Sala is a National Geographic Explorer-in-Residence who combines science, exploration and media to help restore marine life. Sala’s scientific publications are used for conservation efforts such as the creation of marine protected areas. 2005 Aldo Leopold Leadership Fellow, 2006 Pew Fellow in Marine Conservation, 2008 Young Global Leader at the World Economic Forum.
  • James Waters

    I think the bottom line is that man by nature will distroy the earth ie “overfishing the oceans” if something isn’t done to stop him. We must find a way to control over population and feed the masses without causing our own demise in doing so.

  • John Pettey

    Over population may be the cause of “overfishing the oceans” but over consumption and waste is a big problem. Current economic thinking means that growth in consumption is inevitable. I would support economic activity based on quality rather than consumption, in that way, we might begin to redress the balance of the damage done to nature, and reduce the profligate use of finite resources.

  • […] from Enric Sala of National Geographic News, more on the impact of the global jellyfish population explosion: A new study by Robert Condon of […]

  • elliott k

    it’s not just salt water jellyfish freshwater jellyfish are blooming at alarming rate all across the u s in lakes and ponds

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