Kelp Watch 2015 is a scientific campaign, based on collaboration between Dr. Steven L. Manley (Department of Biological Sciences, California State University- Long Beach) and Dr. Kai Vetter (UC Berkeley and Lawrence Berkeley National Laboratory), and designed to determine the extent of possible radionuclide contamination (primarily Cesium-137 & -134) of our kelp forest ecosystem from seawater arriving from Fukushima in 2014. Initiated by Dr. Manley in early November 2013, the project relies on sampling canopy blades of the Giant Kelp (Macrocystis) and Bull Kelp (Nereocystis) several times during 2014. The project started as California centric but has continued to grow beyond the California coastline and includes locations in Baja-Mexico, Oregon, Washington, British Columbia and Alaska. Although kelps (brown seaweeds of the Order Laminariales) do not occur in tropical waters, related brown seaweed, Sargassum, was collected from waters off Hawaii and Guam. To date a total of 48 separate populations were sampled, 31 in California waters, led by 52 marine scientists and numerous assistants. The participants are primarily from academia but also include educators from private organizations. Initially, all participants agreed to participate “pro bono.” Early in 2014, USC-Sea Grant and California State University Council on Ocean Affairs, Science & Technology (COAST) agreed to contribute funds which helped defray the costs associated with shipping and processing the kelp.





Kelp Watch 2015 has officially ended with the analyses of samples collected during the spring and summer of 2016. There was no indication that the radioactivity from Fukushima became incorporated in the coastal kelp beds sampled. Legacy Cs-137 (half life - 30 y; from weapons testing in the 50s and 60s) was detected in all samples, however no Cs-134 (half life 2 y) was detected in any samples. The presence of Cs-134 in kelp would have indicated the presence of Fukushima derived radiation. Surprisingly, low levels of Iodine-131 (half life 8 days) was present in all kelp samples taken from the ports of Los Angeles and Long Beach indicating a persistent local source.





