Are jellyfish mixing up the oceans?


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This is a question that appears to cause some controversy. It was first asked in a paper published back in 2009. Now, one of the authors of that paper is hoping that by providing clear video instruction via an online video journal, other researchers will adopt the technology and use it to gather more evidence to support her theory.

"We felt that it is such a powerful tool that isn't being used in the community," she said. "And I feel that people learn so much better from visual material than they do from just reading text."

Dr. Kakani Katija Young and her team at the Woods Hole Oceanographic Institute published an article in the Journal of Visualized Experiments (JoVE) this month, explaining how to use a Self-Contained Underwater Velocimetry Apparatus (SCUVA).

The apparatus in question is used underwater to light up animals, like jellyfish, swimming in the ocean and is used at night.

SCUVA also illuminates the particles around the animals, showing how the animals move the water around them when they swim. By coupling the HD video images captured by SCUVA underwater with Digital Particle Image Velocimetry (DPIV) software, velocity fields of flow can be revealed.

Dr. Young worked on the original paper: A viscosity-enhanced mechanism for biogenic ocean mixing  – which suggested that the combined swimming effort of jellyfish and other marine organisms, including zooplankton, were responsible for increasing the rate at which heat can travel through the ocean, and might even influence the global climate on the same magnitude as wind!

For more information, and to view the journal video, please see the article: Katija, K., Colin, S. P., Costello, J. H., Dabiri, J. O. Quantitatively Measuring In situ Flows using a Self-Contained Underwater Velocimetry Apparatus (SCUVA). J. Vis. Exp. (56), e2615, DOI: 10.3791/2615 (2011).

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