Since February of 2014 members of SLO Mothers for Peace have periodically taken samples of ocean water from just south of the Pismo Pier and sent those samples to Woods Hole Oceanographic Institute (WHOI) to be tested for radioactive content. Ten of these samples have been taken so far with the last sample showing a dramatic increase in Cesium 137 (Cs137) from the previous sample taken in July 2017.


The sample taken on July 26, 2017 showed 2.1 + 0.1 Becquerels per cubic meter of sea water (Bq/m3). The sample taken on February 2, 2018 showed 6.8 + .02Bq/m3; a more than 300% increase in the amount of Cs137 detected.

The first sample taken on February 9, 2014 showed 1.8 +.01Bq/m3. The 2018 sample is five times higher than the first sample taken in 2014.

Woods Hole Oceanographic Institute in Falmouth, Massachusetts stated in their update for March 2018 that; “It is important to note that, prior to these events in 2011; there were already measurable amounts of radioactive fallout in the ocean left over from the testing of nuclear weapons that peaked in the 1960’s. For cesium-137, levels in Pacific Ocean surface waters were generally below 2.0 Becquerels per cubic meter (Bq/m3).1 We now see cesium-137 levels above this level at locations along coastlines in California, Oregon, Washington, British Colombia ,and Hawaii, as well as higher levels offshore (Figure 1). This increase, as well as our finding of cesium-134 in these elevated samples, provides clear evidence that Fukushima contamination has reached our shores.”

While these levels are below those “of regulatory concern”, it is vitally important that this testing of our oceans waters off the Central Coast continue. The nuclear meltdowns and disaster at Fukushima continue to pour irradiated water into the Pacific every day; these radioactive levels will most probably continue to go up.

If you would like more information on this project or would like to see the results of all of the tests taken please see either the Mothers for Peace website https://mothersforpeace.org/ or the website of WHOI, How Radioactive is Our Ocean http://www.ourradioactiveocean.org/ .