Massive Starfish Die-Off Baffles Scientists

The waters off British Columbia, Canada, are littered with dead starfish, and researchers have no idea what’s causing the deaths.

At the end of August, marine biologist and scuba enthusiast Jonathan Martin was out on his usual Saturday dive with some friends when he noticed something unusual.

A decomposing P. helianthoides starfish still clinging to a rock. Photograph courtesy Jonathan Martin

“We just started noticing dead starfish that looked like they had their arms chopped off,” Martin said.

They were sunflower starfish (Pycnopodia helianthoides), a major marine predator in the area that feeds mostly on sea urchins and snails. Like most starfish, the sunflower starfish can regenerate lost limbs—it can have up to 20—and can grow to be up to three feet (a meter) across. (Related pictures: “5 Animals That Regrow Body Parts.”)

Since Martin was diving in an area frequented by crabbers, at first he thought the sunflower starfish had gotten caught in some of the crab traps and had lost limbs escaping. But Martin kept seeing large numbers of dead starfish as he and his friends swam to a marine park where such crab fishing is illegal. Martin knew then it wasn’t the traps that were causing the starfish deaths.

After returning from the dive, he visited friends at a local dive shop who were active in marine conservation. Without any definitive answer, he shared photos on Flickr and videos on YouTube—taken at Lion’s Bay and Whytecliff Park in Vancouver—to try to get ideas from others about what was going on.

“It really struck a chord in other divers who were seeing it on Facebook and social media, both locally and as far away as California, who had been seeing similar things,” Martin said.

Searching for a Cause

Still without any answers, Martin wrote to invertebrate expert Christopher Mah, a researcher at the Smithsonian Institution in Washington, D.C., and author of the Echinoblog. In his email, he said:

“[The starfish] seem to waste away, ‘deflate’ a little, and then just … disintegrate. The arms just detach, and the central disc falls apart. It seems to happen rapidly, and not just dead animals undergoing decomposition, as I observed single arms clinging to the rock faces, tube feet still moving, with the skin split, gills flapping in the current. I’ve seen single animals in the past looking like this, and the first dive this morning I thought it might be crabbers chopping them up and tossing them off the rocks. Then we did our second dive in an area closed to fishing, and in absolutely amazing numbers. The bottom from about 20 to 50 feet [6 to 15 meters] was absolutely littered with arms, oral discs, tube feet, gonads and gills … it was kind of creepy.”

On his blog, Mah speculated as to some causes, including a type of parasite that lives on starfish—the leading hypothesis at the moment, Martin said. (See more starfish pictures.)

starfish arm
A lone starfish arm. Photograph courtesy Jonathan Martin

Both Mah and Martin also wonder if a population explosion of the species, which began about three years ago, has something to do with the deaths.

“It was an unprecedented increase, so maybe what we’re seeing is just sort of a bursting of the bubble. The animals just reached a density that was unsustainable,” Martin suggested.

Starfish Not Alone

Yet what’s especially alarming to Martin, Mah, and other marine biologists is the fact that this die-off might not be restricted to P. helianthoides or the northern Pacific. Martin has spotted other dead invertebrates besides the sunflower starfish, including its predator, the morning sun star (Solaster dawsoni).

sun star picture
The morning sun star (Solaster dawsoni) is also affected by the die-off. Photograph courtesy Jonathan Martin

Earlier this summer, researchers also noticed a massive die-off of another starfish species on the U.S. East Coast. Scientists at the University of Rhode Island first noticed the large numbers of deaths of Asterias species—part of the same family as the sunflower starfish in British Columbia—in 2011, and since then, dead starfish have been documented along the eastern seaboard from Maine to New Jersey.

Fisheries and Oceans Canada is worried enough that they’ve asked Martin to go back out and collect samples for them to test in the lab. Although the agency has expressed interest in the die-off, Martin says that starfish aren’t a major research priority, and the main burden of investigation and discovery has fallen on him and other divers with an interest in marine ecology.

Meanwhile, Martin cautions people to not jump to conclusions.

“When I posted this on Facebook, some people immediately thought that this was due to global warming or other human-related activities. While that’s certainly a possibility, it’s all speculation.”

What do you think caused the die-off?

Follow Carrie Arnold on Twitter and Google+.

Carrie is a freelance science writer living in Virginia. When she's not writing about cool critters, she's spending time outside, drinking coffee, or knitting. You can visit her website at http://www.carriearnold.com
  • Adam Evenson

    How could any massive species die-off in the ocean baffle anybody, especially scientists? Humankind has succeeded in poisoning the entire planet, particularly the oceans. Think about only two incidents of many: Fukushima nuclear radiation spreading over the whole planet, and the Horizon BP oil spill in the Gulf of Mexico. Fukushima, alone, is enough to fill any “massive ocean species die-off” bill. Humankind has lost its mind.

  • w piitz

    could it be the radiation caused by Fukushima? They’re
    predicting it to hit our coast in 2014. What’s to say it isn’t
    here right now and this is just the beginning. So sad.

  • Craig

    Allow me to post the only rational comment and say radiation to show up on the sea floor would produce cancer and legions – not arms falling off. People – please use science and facts and stop conjecture and bible prophesies.

  • Krissy Boyce

    Sad. Research into it will only create more speculation. I hope they can find an answer and solve the issue asap. More than one reason causing this unreal death toll.

  • Laird Kerr

    Not likely a radiation spill, too diluted and would not cause such a sudden die-off. More likely a biological agent like a virus. Fish farming has introduced some new viruses to the local wild fish populations so that could be a source. The farms are very unnatural to the normal balance of the ocean.
    What is “really” disturbing is that this issue has not hit mainstream media…that usually means that the issue is known at some high level and that the truth is being suppressed… That kind of global media manipulation is far more dangerous than a new fish farm plague…

  • Jason

    We are noticing the same phenomenon here in central CA. So far I’ve only seen sunstars. I only started seeing/hearing about them in the last few weeks. I am currently polling other local divers to get spatial, temporal, and depth ranges for this event.

  • Donna Friesen

    In September 2013 we spent 6 days on Qualicom Beach in Bowser. On the Tuesday we were there we were pleased to witness the arrival of several hundred healthy and colorful starfish. The colors ranged from beige to burgundy and even bright yellow and orange. They did, however, not return for the rest of our stay. We heard around our resort that a scallop farm had destroyed a lot of the starfish and the bullwhip kelp and people were glad to hear that we had seen and photographed so many of these beautiful creatures

  • John

    and now we also have 1/3 of honey bees die off last year alone, and they expect that number to keep decreasing by 1/3 every year for the foreseeable future. The attitude of money is God is going to have to change. Open up the black files where they shelf alternatives to oil and nuclear and get real about the worlds situation.
    It doesn’t take a lot of thought to realize humans are somewhere in the line to start experiencing the same or maybe thats the whole purpose of ignoring it. Some say thats a good thing, so,,, who wants to volunteer?

  • Griffin

    Please, for the love of god, call them SEASTARS!!!! They are not fish!! This is National Geographic, pull it together!

  • bluesapphire48

    Whether it is radiation from Fukushima or global warming, the starfish certainly have not benefitted from the ACTIVITIES OF MAN.

  • Dan

    @ Griffin
    For the love of god, they aren’t “stars” either.

  • Jamieson

    What you’re viewing is from:
    “Radiation & Toxins”.
    1. “Fukushima” is the main culprit.
    2. Following Fukushima is biological weapons & warfare.
    i.e. Hawaii.
    All the best,

  • Dan

    Global warming what joke ..

  • Phil Garner

    I’ve been diving a reef frequently over the past two months. It has more Sunflower stars there than any other reef in the area. Yesterday there were several disintegrating stars on the reef. We had a fluctuation in water temperatures one day last month. The water warmed seven degrees Fahrenheit and then cooled back down three hours later. If I begin to disintegrate I’ll sue Fukushima. 🙂

  • the railer

    Just a reminder that radiation does not, I repeat, does not dilute, it just travels…or rather, spreads. This is from the IAEA’s report from 1955 and from several scientists studying the nuclear plants in UK and FR that directly pump the waste into the ocean. Yes, I am not lying-this practice is frightening and unless you are involved in trying to stop it, it will most probably continue until we take our last breath. This outbreak may not be from Japan but I thought everyone should know that it could be, for obvious reasons.

  • Tom Petrie

    Don’t know what’s causing this horrible issue, but my first inclination is Fukushima. Ninety percent it is this. But it could be something else, of course.

  • Ed Ward, MD

    Scientists baffled by marine deaths. Of course they are, when they refuse to the do the extremely simple task of putting an appropriate Geiger counter near the corpse. You can NOT find what you refuse to test for. “San Onofre Edison… West Coast Radiation Crisis – Part 1”

    FUKUshIMA: Seven Waves, Away… Abandon Ship

  • Patrick Smith

    I just returned from a 5-day underwater survey of the northern Channel Islands (Anacapa, Santa Cruz, Santa Rosa and San Miguel) and although the focus of our dives was not biological, it was noted that the population of sunflower starfish (Pycnopodia helianthoides) appeared healthy and in fact there was comment made on the very large number of juveniles seen. It appears on a very cursory look over a fairly large area that recruitment for this species, at least in the Channel Islands area is fairly robust.

  • Evan Kopelson

    It’s amazing that scientists seem baffled, while on this and other articles about the starfish, in the comments sections, everyday ordinary people with regular common sense are talking about radiation and toxicity of the oceans. What happened in Hiroshima after people were exposed to radiation? Their limbs fell off and their skin melted, among other things like total failure of their organs. Why are scientists baffled? Starfish absorb everything they are exposed to. I’m amazed at the baffled scientists who don’t seem to have any common sense to even postulate that this might be a cause, no less the obvious one.

  • Sal


  • delta99

    Where did people get the idea this is radiation from Fukushima?

    Whatever it is, it appears to be affecting the east coast as well.

    Has radiation from Japan infected the Atlantic as well?

    I have no idea what it is, but I think bacteria, virus or parasite are much more logical explanations. Hopefully a cause and a solution will be found soon.

  • Dexter Redland

    to say that Humans are causing the die off as if we are not an integral part of Nature doesn’t make sense to me. Nature need not communicate through language. Nature has way cooler communication methods. we … cannot speak for Nature … when we think we can that’s when we get blind-sided by previously unknown asteroid. game over, i hope the specialists in these fields of study can determine the cause and, if appropriate, prevent or mitigate it. ugh. PAAAATRRRIIIICKKKKKKK!!!!!

  • Kirk

    Did any of you biblical and radiation theorists bother to read the article that clearly states another species had the same thing happen to it on the East Coast in 2011 ?! You people are a trip :-/

  • chapin

    I wonder if it has anything to do with radiation from the incident in Japan with the nuclear plants. There is also a die off of dolphins off the coast of california, and a die off of sea lions.

  • ChemE

    I am an industrial chemical engineer in the US. For the past 10 months I have been plotting algae blooms, fish and mammal kills (manatees, dolphins, etc), waterspouts and sinkholes in Google Earth and it has led me to believe it is our High Powered Dual Pol Doppler radar towers adding to the damage to biology. Each tower is pulsing 0.25 – 1.25 Megawatts of microwave radiation into the overhead atmosphere and I believe much of that energy is absorbed, attenuated and redirected towards Earth and waterways, gradually ionizing the surroundings at a higher rate then normal. Since it is low frequency (centimeters in wavelength) I believe it is very penetrating and is ionizing dissolved oxygen from the waterways. They recently upgraded many of them to dual polarization which I think may be making it worse. Think of the atmosphere as a capacitor discharging to the Earth as a battery and you will understand what I mean. >80% of fish kills due to algae and large sinkholes during storms in Florida are happening near Doppler towers. The Sitka, Seattle and Pillar Point sea star wasting sites are all very near high powered doppler/radar sites as well as further South. 1 megawatt is instantaneous is enough to power 500 homes.

  • Daryl

    If only this wasting disease where affecting the human race. That would be the only thing that would save the planet.

  • Jason Chorostecki

    @Griffin…What’s your name for the seahorse? It’s not a horse.

  • bukwheet

    radiation bonds with hydrogen atoms / what is water? hydrogen!!! / been raining nuclear fallout for 2 years in increasing levels / winds and currents are westerly flows across the Pacific / North American Continent is now a Nuclear Easy-Bake Oven / buy a dosimeter and impress your friends (O,o)

  • RMJ Atkinson

    I would not dismiss Fukushima. Even if it is not to blame in this case, it is going to have an effect. And on the East Coast – think – Gulf of Mexico and the poison they used to clean up the oil. I sure hope it is a natural die-off, but something tells me it is not, and especially so when scientists are so quick to discount it.

  • EXPO JO SHOW (facebook)



  • adr

    Why do so many average people think researchers aren’t testing for radiation? That was one of the first things ruled out by NOT finding elevated radiation levels in affected sea star samples. They did and continue to test for radiation levels. Scientists are not stupid.

  • efraim, gonzalez

    Could any of this have anything to do with the chemicals they used to clean up the oil spill or possibly , the chemtrails

  • WakeUpSheep

    It’s not rocket science. It’s call FUKISHIMA and CHEMTRAILS

  • Genodr

    Never let a good crisis go to waste.

    Global warming cult attacks radiation to defend orthodox beliefs. So, no problem, let them keep eating Pacific sushi.

    The environmental movement is self destructing like star fish. Sad.


  • has20birds

    Same problem in California. In fact, this is why all the almond trees are dying? Water for fracking?

    This report is 32 pages long. It’s called Dirty Water: Fracking Offshore California

    The Environmental Defense Center (EDC) addresses the oil industry’s use of hydraulic fracturing (akafracking) and other forms of well stimulation from offshoreplatforms located within federal, Outer Continental Shelf (OCS) waters in the Santa Barbara Channel. The Santa Barbara Channel and the Channel Islands are renowned globally for their beauty, richness of wildlife,and overall health of the environment. Although fracking has been conducted off of California’s shores for at least two decades, the practice was until recently largely unknown to state and federal regulators, as well as the general public.


    If this link
    doesn’t work just search the name of the report (above)

    The Energy Information Administration (EIA) recently identified California’s Monterey Shale, encompassing large portions of the southern and central portions of the state, both on and offshore, as the nation’s largest oil shale “play.” The agency estimates that the Monterey harbors 15.4 billion barrels of “technically recoverable” oil, more than 60 percent of the nation’s total estimated shale oil resources. Although a true oil shale boom has not yet occurred, fracking for shale in California is already on the rise, with at least 1,200 fracs performed in the state since January 2011. The technological advancements driving today’s “modern” fracking pose new and largely unstudied environmental and public health risks that are cumulative to the significant impacts arising from “traditional” oil and gas production. For example, today’s fracking relies on “frac fluids” containing extensive amounts of chemicals, many undisclosed under trade secret and other business confidentiality laws. Compared to past practices, fracking is now conducted further below the surface (often more than two miles), down wells that pass through groundwater aquifers commonly relied upon for domestic and agricultural use. And fracking today relies on the use of much larger quantities of increasingly scarce freshwater supplies than past oil and gas operations.

  • MI


  • Hibiscus Jazz

    I saw something like this happen to starfish in the US Virgin Islands. The starfish looked like they were trying to come ashore and it was as if they were melting. It was absolutely horrific and sad. It was almost like the water was toxic and they were trying to escape. It was around 2013 when I saw this happen.

About the Blog

Researchers, conservationists, and others share stories, insights and ideas about Our Changing Planet, Wildlife & Wild Spaces, and The Human Journey. More than 50,000 comments have been added to 10,000 posts. Explore the list alongside to dive deeper into some of the most popular categories of the National Geographic Society’s conversation platform Voices.

Opinions are those of the blogger and/or the blogger’s organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic’s community rules and other terms of service.

Voices director: David Braun (dbraun@ngs.org)

Social Media