Everything You Need to Know About Fukushima’s 'Radioactive' Whales

This week marks five years since the Tōhoku earthquake sent a wall of water barreling towards Japan, resulting in the nuclear disaster that put “Fukushima” in most of our vocabularies. Five years have passed, and yet even now, the nuclear disaster continues to fuel misguided panic-spirals in the media.

The most recent report, which has ricocheted around the web like a pinball this month, revolves around a string of “unexplained” whale deaths. The strandings certainly seem like cause for concern, but despite the kerfuffle, there’s something you need to know about radioactive whales in the Pacific Ocean: there aren’t any.

It makes sense that whale strandings get ample media attention. After all, there’s nothing quite like a giant, smelly, potentially-explosive carcass to generate a buzz.  But the reality is that whales strand for a multitude of reasons, from ship strike and sonar damage, to disease and dehydration. Just because whales wash up dead within months – or even weeks – of each other, does not give cause to suspect a sinister link between them. There's no evidence to suggest that any of the recent whale strandings, from the U.K. sperm whales, to Oregon’s big blue, had anything to do with Fukushima radiation.

Most of these cases have already been solved by scientists: the sperm whales in both Britain and Germany, for example, fell victim to the shallow North Sea, which acts as a whale trap under the wrong conditions. Oregon’s blue whale swam too close to shore, driven inland by a warm-water blob that’s been plaguing local krill populations.  Others, like Alaska’s fin whale deaths, remain unsolved mysteries, but as comparative anatomist Dr. Joy Reidenberg explains, a cryptic cause of death doesn’t point to a radiation crisis. Death by radioactivity is messy, takes time, and follows a pattern.   

“[First], I would think there’d be immediate deaths from the radiation,” she says. (There were none. And in case you’re wondering, Fukushima did not irradiate these dolphins’ lungs.” That story has long been debunked.) “Then we’d see a series of birth defects in the next generation born of the exposed survivors, followed by a series of deaths from cancers that would take much longer to manifest."  (Neither of which have been observed to date, despite what Facebook collages might tell you).

It takes a lot of radiation to kill a whale, or give it cancer

Using radiation as a blanket scapegoat to explain mass-strandings is problematic in many ways, but the biggest hole in this argument is the amount of radiation it would take to kill a whale, and what that kind of exposure would do to the rest of the marine ecosystem.

In the months following Fukushima, a swim in Japan’s waters would only have dosed you with 0.03 percent of the daily radiation an average Japanese resident receives, and that number continues to drop due to natural decay of the radionuclides released from Fukushima. These levels are non-lethal to humans, let alone 16-ton leviathans. But even if none of that were true, swimming through contaminated water wouldn’t cause a whale to drop dead. A lethal dose would have to come from eating affected prey.

There’s a reason that “red tide,” that toxic bloom of algae that keeps us from eating tasty bivalves, often results in die-offs of fish and invertebrates, but rarely whales. It’s the same reason that we can toss the Fukushima hypothesis aside: when it comes to ocean contamination, the little guys are always hit first.

This pattern arises because ocean contaminants build as they move up the food web: accumulating first in plankton and other primary consumers, then in the fish, invertebrates, and filter feeders that eat them, and eventually in larger mammals and other top predators.

If a radioactive isotope – or any contaminant for that matter – was potent enough to cause whale die-offs, we would expect to see a slew of other species washing up beside them. This occurred in exactly zero of the recent viral beachings.

Scientists haven’t stopped watching for trouble

While fearmongering articles do a great job of beating the Fukushima hypothesis into the minds of readers (a quick search of this one resulted in a whopping 24 mentions of the disaster), something they often fail to address is that scientists are still testing radiation levels across the Pacific.

Marine mammal specialist Kate Wynne, for example, has been tasked with investigating whale deaths in Alaska – including the aforementioned fin whales – in the years since the catastrophe. And of all the carcasses she’s sampled, including one that washed up last summer, none have come back positive for high levels of cesium-137 that would indicate contamination from nuclear power plants, or any other radioactive isotope.

Tests like these have been and will continue to be performed up and down the West Coast, as well as in Japan. We’ve tested the air in Berkeley; we’ve tested salmon in Alaska; we’ve tested California’s milk. Scientists are looking for alarming Fukushima radiation, and they simply haven’t found it.

But what about that radioactive sand?

While scrolling through Fukushima fodder, you may stumble across reports that claim the sand in San Mateo County’s Half Moon Bay shows elevated levels of radiation. And while this is true, it is not indicative that Fukushima fallout is accumulating on the California coastline, nor is it indicative of any danger our ocean-dwelling neighbors.

Back in 2014 Dan Sythe, who has been designing Geiger counters for nearly half a century, put that myth to the test – and it failed. Miserably. What he discovered in Half Moon Bay were elevated levels of radium-226 and thorium-232. That sounds scary, but unlike Fukushima’s cesium-137 and 134, these isotopes are naturally occurring radioactive material.

In fact, the radioactivity in the sand was roughly that found in any granite countertop material imported from Brazil. When it comes to radiation, detectable does not necessarily mean hazardous.

If radiation isn't killing whales, why are whale strandings on the rise?

Noteworthy mass-strandings of dolphins, whales, and other marine mammals date back to the time of Aristotle. We see more of them today for the same reason we see more albino animals and fatal shark bites: there are more of us. According to Woods Hole Oceanographic Institute whale biologist Dr Darlene Ketten, the frequency of reported strandings over the years seems to coincide with human population growth.

Before you jump up in protest of this simple explanation, consider this: sure, more beachgoers means a statistically higher chance that someone will spot a stranded animal; that part is obvious. But a global population of 7.1 billion people also means more chemical contamination, plastic pollution, rapidly-warming waters – get the picture? Nuclear radiation is an invisible adversary – you can’t smell it, you can’t feel it, you can’t see it. It’s inherently spooky, but it’s far from the biggest danger facing our oceans.

If we’re meant to save the incredible life that inhabits those oceans, our attention needs to be focused on the damage that’s quite literally happening before our eyes. By focusing on Fukushima, we’re ignoring the environmental factors that actually could be behind the deaths of these whales.