Jellyfish Taking Over Oceans?

  • A jellyfish under the Ross Sea ice, on October 14, 2005 (Photo by Henry Kaiser, courtesy of the National Science Foundation)

Some scientists are warning
that as overfishing and climate
change affect the world’s oceans,
jellyfish will take over the
ecosystem. That could mean that
eventually, if you cast a net
into the ocean all you’d haul
in would be jelly blobs. But
as Ann Dornfeld reports, such
warnings may be premature:

Transcript

Some scientists are warning
that as overfishing and climate
change affect the world’s oceans,
jellyfish will take over the
ecosystem. That could mean that
eventually, if you cast a net
into the ocean all you’d haul
in would be jelly blobs. But
as Ann Dornfeld reports, such
warnings may be premature:

The theory goes like this. Overfishing is removing the main jellyfish predators from the oceans. And warming oceans could be more hospitable to jellies.

A new report published in the journal Trends in Ecology and Evolution says jellyfish are already taking over. Its authors point to recent big jellyfish blooms as evidence.

But not everyone’s convinced.

“I think there’s a set of people that are sensationalizing the jellyfish bloom issue.”

University of Washington researcher Claudia Mills has been studying jellies for 30 years.

“I do think that probably jellyfish blooms are on the increase. But the problem is, we have so little baseline data that it’s almost impossible to really, honestly know that.”

Mills says there’s hardly any historical data on jellyfish populations, and not even much recent data.

She says it could be that the future of the world’s oceans is gelatinous and tentacled… or the blooms could just be cyclical.

For The Environment Report, I’m Ann Dornfeld.

Related Links

Modified Fish to Protect Water Supplies?

Some scientists working on protecting freshwater supplies from terrorism are trying to recruit a new special agent. It’s a small fish that may serve as a sentinel of contamination. The Great Lakes Radio Consortium’s Chuck Quirmbach reports:

Transcript

Some scientists working on protecting freshwater supplies from
terrorism are trying to recruit a new special agent. It’s a small fish that
may serve as a sentinel of contamination. The Great Lakes
Radio Consortium’s Chuck Quirmbach reports:


Researchers are injecting firefly genes or a fluorescent
jellyfish protein into a small tropical freshwater species
called the zebrafish. The hope is that when the genetically
modified zebrafish is exposed to environmental pollutants or
chemical warfare agents, the fish would give off light or a green signal.


University of Wisconsin-Milwaukee scientist Michael Carvan says the
fish would be placed in water coming in from a source such as Lake Michigan.


“This would kind of be like the canary in the coal mine… where if the fish
signaled that there were toxic chemicals in the water… that that would alert
the system and probably shut down water that would go beyond that point.”


Carvan acknowledges that he’s having trouble getting the zebrafish to pass along
the so-called green gene from generation to generation.


For the Great Lakes Radio Consortium, this is Chuck Quirmbach in Milwaukee.