Kelp Watch 2015 is based on collaboration between Dr. Steven L. Manley from the Department of Biological Sciences at California State University, Long Beach and Dr. Kai Vetter of the UC Berkeley and Lawrence Berkeley National Laboratory. The project was designed to determine the extent of possible radionuclide contamination (primarily Cesium-137 & -134) of the local kelp forest ecosystem from seawater arriving from Fukushima in 2014.
Initiated by 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 that 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 (from weapons testing in the 1950s and 1960s) was detected in all samples, however no Cs-134 was detected in any samples; the presence of Cs-134 in kelp would have indicated the presence of Fukushima-derived radiation, according to researchers. Surprisingly, low levels of Iodine-131 was present in all kelp samples taken from the ports of Los Angeles and Long Beach, indicating a persistent local source.
“Results from our fifth sampling period from March through June of this year were very similar to the previous sampling periods obtained over the past two years and demonstrate no detectable amounts of Cesium 134 or elevated Cesium 137 levels in kelp that could be attributed to the Fukushima disaster,” Manley said.
Manley and Vetter chose kelp because it tends to concentrate these radioisotopes. All kelp samples taken over the entirety of the project from the ports of Long Beach and Los Angeles contained low amounts of Iodine-131, which could not have arrived via the atmosphere or ocean currents from Fukushima. Its presence is due to a persistent local source, most likely a small waste water treatment plant.
After the latest findings, Manley and Vetter have now concluded the Kelp Watch studies.
For more information about the project, visit kelpwatch.berkeley.edu.
Source: CSULB
