DV-11-10 Ensuring the safety of Maine's edible seaweeds

C.T. Hess
Department of Physics & Astronomy
Bennett Hall
University of Maine
Orono, ME 04469

The nuclear disaster at the Fukushima Daiichi power plant following the 8.9-magnitude earthquake in Japan in March 2011 released radioactive particles into the global atmosphere. In April 2011, radioactive iodine was detected in air samples from above Bennett Hall on the University of Maine campus. Iodine in the environment is accumulated at high levels by marine macroalgae or seaweed, including three groups of seaweeds that are collected by Mainers for personal consumption or as part of commercial enterprise: rockweeds (Ascophyllum nodosum, Fucus spp.), kelps (Saccharina/Laminaria spp.), and dulse (Palmaria palmata). Iodine is stored by the kelps, at least, as an antimicrobial organic compound, which is secreted into cell walls under stress from pathogen attack. Iodine is also interpreted as being part of a suite of anti-herbivore compounds used by some red algae.

With assistance from students, UMaine professor Dr. Susan Brawley, and staff from Maine Coast Sea Vegetables, Hess sampled three species of seaweed from several locations on the Maine coast. After thorough measurement of more than 50 samples, no radioactive iodine was detected, ensuring the safety and nutritional benefits of Maine sea vegetables.