Environment & Science

Fukushima radiation not detected in kelp beds yet

Biologist Steven Manley collects kelp samples for the first round of testing in the Kelp Watch 2014 project.
Biologist Steven Manley collects kelp samples for the first round of testing in the Kelp Watch 2014 project.
David J. Nelson/Cal State Long Beach

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A project to monitor radiation levels from the Fukushima nuclear leak in kelp beds on the West Coast has found no contamination in its initial testing.

“So far there’s no detectable amount of Fukushima radiation in any of the kelp samples that were looked at,” said biologist Steven Manley, who heads Kelp Watch 2014 at California State University at Long Beach.

The study kicked kicked off earlier this year when Manley teamed up with researchers from Alaska to Chile to collect samples from kelp beds up and down the West Coast and test them at Lawrence Berkeley National Laboratory for radioactive isotopes like Cesium 134 and 137.

Kelp is particularly sensitive to changes in radiation levels because it soaks up the contamination like a sponge. Manley calls it a “sentinel” species that is found in abundance along the Pacific coast and is the basis for an entire ecosystem.

Researchers took their first samples in March, a month before the first radioactive waters were expected to reach the West Coast from Japan. The plume was expected to make landfall first in the Pacific Northwest due to current patterns.  

Manley said the results of the first round of tests will serve as a baseline against which to compare future samples. The samples did not contain detectable amounts of the short-lived radioactive isotope Cesium 134, which is the main contaminant related to the Fukushima leak.

A small amount of Cesium 137, a long-lived isotope present since the 1950s and '60s as the result of nuclear testing and the Chernobyl disaster, was found in the kelp, along with small amounts of natural radiation in the form of Potassium 40.

Researchers will collect a second round of samples in August and again later in the fall. Manley said he expects only a small amount of radiation will be present because of ocean water dilution. Still, researchers will continue monitoring the levels through the end of the year.