Why are starfish literally ripping themselves apart off the Pacific Coast? We’re an environment journalist and a diver/videographer reporting on the mysterious disease. Ask us anything.

I have a question: Why are starfish literally ripping themselves apart off the pacific coast?

A network of scientists on both coasts received rapid response funding from the National Science Foundation to investigate the die-offs. It’s one of the fastest-ever mobilizations of research around a marine epidemic. Diver Laura James and I have been following the infectiousness experiments that they're conducting here in Puget Sound. They're also taking samples from dying starfish up and down the west coast to send to a lab at Cornell University. They're using DNA sequencing and metagenomics to analyze the samples for viruses as well as bacteria and other protozoa in order to pinpoint the infectious agent among countless possibilities. It really is like a matrix, but from what scientists are telling us, they're homing in on the cause and may be able to make an announcement in a few months. We'll be sure to follow up.

I understand this has happened in the past. How is this more concerning than past die-off events of sea stars?

For this die-off to involve 12 different species dying rapidly across such a large latitudinal scale makes this an event scientists haven't seen before. That's why they're making it a high priority to understand both how it started, how it’s propagating, what the rates of transmission are and what kinds of infectious agents might be involved.

Thanks for the answer. Is there any comminality in the species being affected that has been identified? Or does it appear that 12 species at random appear to be targeted.

In other words, is there a marker that identifies these particular species as being vulnerable?

The top 5 species that have been impacted most intensely are from the family Asteriidae so that's a clue to this mystery. But I don't think scientist know yet what specific characteristic or marker might make them more vulnerable.

Aren't starfish incredibly simple creatures, though? I would have thought their genetic makeup, even across species, wouldn't be too different.

I actually asked a very similar question of scientists. And they explained to me that sea stars are actually a large and diverse class. There are about 1,500 living species and within that there are seven different orders.

Do you think this is caused by a biological illness or could it be related to Fukushima?

The short answer is almost definitely no. Scientists do not see a connection between the massive die-offs of starfish along the Pacific shores of North America and Japan’s Fukushima nuclear disaster. Here are some reasons why: 1. Recent tests for radiation in seawater along the west coast have found “no detectable Fukushima cesium.” While small amounts of radioactive have reached the west coast, the largest concentration of radioactive water released during the nuclear meltdown is still moving across the Pacific. Scientists predict that the radiation plume will reach the west coast of the United States by around April 2014. 2. The die-offs are patchy. This doesn’t line up with a giant plume of radiation moving across the Pacific. They’re popping up in certain places like Seattle and Santa Barbara and not in others, such as coastal Oregon, where there’s only been one report. 3. Sites closer to the Pacific shorelines are being affected sooner than places farther out to sea. And there have not been reports of starfish die-offs in Hawaii or Japan. If Fukushima were the cause, it would stand to reason that starfish closer to the source would also be impacted. 4. Sea star wasting syndrome predates the Fukushima nuclear disaster. Some of the earliest accounts of sea star wasting took place in the late 1990s. The Fukushima nuclear disaster happened in March 2011.

I was wondering this, too. You mentioned Fukushima in your promo for the AMA, but not in the video. Has it been ruled out?

As I wrote the script for the video, I decided not to raise the issue of Fukushima because all the research I'd conducted through extensive interviews with scientists lead me to feel that raising this issue would be directing too much attention to an issue that scientists had largely ruled out. Fukushima felt like a red herring. However, once the video was released, hundreds of commenters have declared that the die-offs must be caused by Fukushima. So I've been trying to follow up and explain further why scientists don't believe this is the likely cause. Here's the latest article I wrote.

Thank you for the AMA. I started hearing about a decrease in starfish in the SF Bay Area a couple of years ago. People started noticing fewer on posts/piers above water than previously. How long have experts been tracking this? What is used to determine how long it's been going on?

Good questions... Tracking marine diseases is extremely difficult because anything underwater is out of sight and out of mind. We know significantly less about how marine disease travel compared to land-based diseases. And we have little way of knowing exactly when sea stars get sick because as far as we know, they get sick when people start noticing. However, there are a number of groups that conduct regular surveys and this is helping to establish a baseline. For example, there are groups such as the SeaDoc Society and REEF who have divers trying to keep an eye out for these things. A group from the University of California Santa Cruz has also been conducting intertidal surveys of sea star wasting and posting their reports of sea star wasting to this map. Their earliest report of sea star wasting from this most recent series of die-offs was June 2013 on the WA coast.

Is it definitely a disease or virus?

I did home reef-keeping for a few years, and know that the diets of film eating starfish isn't really known at all, and they take an extremely long time to starve to death (possibly 6 months or more).

is it possible this mass die off is being caused by starvation or deficiency of some needed vitamin or mineral or possibly symbiotic bacteria?

Well, the marine epidemiologists I interviewed said it certainly looks and acts like a disease. But they're reluctant to 100% declare it a disease until they know for sure. They're conducting exhaustive DNA sequencing against all the known viruses, bacteria, protozoa, fungi to see try to figure out the exact fingerprint of the disease, if it is indeed a disease. That's why scientists prefer to call it Sea Star Wasting Syndrome. I don't know for sure about the possibility of them starving to death, but it doesn't seem likely because there's just tons of stuff for them to eat down there -- especially in Puget Sound. And starfish aren't exactly picky eaters. They're more like little vacuum cleaners, they'll eat just about anything -- clams, mussels, sea cucumbers, crab, other starfish.

not all starfish are scavengers of large pray, there are many types that eat only film algae on the substrate others prefer to munch on coralline algae, some eat coral.

There are about 1,500 different sea star species so there's a variety of diets within that long list. In general, starfish tend to be voracious predators.

Any other animals having massive die-offs over there? This is the first I have heard of this, but I do live in Florida. We recently had a bout of beached dolphins over on the east coast. Sad stuff.

Also, is it many different species of star fish that this is happening to?

Thanks for kicking things off Mad_Scientist! There have been periodic die-offs of different marine species, but as far as I know right now, people are only seeing the mass die-offs among sea stars. About a dozen different species of sea stars are currently being affected by this die-off, which scientists find alarming. If it were just one species, it would be less concerning.

Has this kind of thing ever happened across multiple species within one group before?

Sorry this question got missed! For this die-off to involve 12 different species dying rapidly across such a large latitudinal scale makes this an event scientists haven't seen before. That's why they're making it a high priority to understand both how it started, how it’s propagating, what the rates of transmission are and what kinds of infectious agents might be involved.

Thanks for doing this AMA. Two basic questions:

• Is it correct to say that each starfish leg has its own 'brain'?

• Would isolating individuals of different species in aquariums be helpful or hurtful in the long run?

Good questions Tgg, Starfish lack a centralized brain, but they do have a complex nervous system and they can feel pain. Many viewers have asked whether starfish can regenerate a new body from a leg that walks away, but in this case the starfish are dying too quickly so they don't have a chance to re-grow body parts once they've ripped themselves apart.

I'll respond to the aquarium question in a few minutes.

Sorry I forgot to come back to the second question. So many questions to respond to, and I'm not sure I'm clear on what you're asking. Are you asking whether it would be helpful for species that are already living in aquariums? Or are you talking about conducting experiments with different species in aquariums?

How are US and Canadian scientists working together on this issue? I presume like all environmental issues, the starfish disease is not stopping at the border.

Also, I'd like to put in a shameless plug for the Salish Sea Ecosystem Conference April 30 - May 2 in Seattle where this, and many other pressing marine science issues will be explored. Here's our website

Researchers from the Vancouver Aquarium, University of Washington, Friday Harbor Labs, University of Santa Cruz (to name a few off top of my head) are now using very similar if not same protocol for their reporting, sharing information, and are communicating in long, robust, collaborative email threads (in which they are also including us citizen scientists).

Add to that list the Western Washington University, SeaDoc Society and Cornell University.

Why should I care about this?

I love this question. :-) First Water is literally is the life blood of a sea star. They are really sensitivity to any changes in salinity and water quality. Toxic materials of any kind could conceivably affect them. So they’re the canary in coal mine and when they're dying by the tens or even hundreds of thousands, it's an indication of something being out of whack in the marine environment. Second Sea stars are voracious predators, like lions on the seafloor. They gobble up mussels, clams, sea cucumbers, crab and even other starfish. That’s why they’re called a keystone species, meaning they have a disproportionate impact on an ecosystem, shaping the biodiversity of the seascape. When a predator species is removed, the prey species can take over and go wild and they end up overgrazing .... it can end up reducing the overall biodiversity of an area.

How exactly are they ripping themselves apart?

Here's what the process looks like in the sunflower star: They seem to develop lesions on their skin and they twist their arms unnaturally into knots. It's almost as if they're trying to cover the lesions on their skin, like an arm Band-Aid. They start to look deflated or not as plump as normal. And then their arms start walking in different directions. The place where the arms connect to the body is stretched until it just gives way. I don't know what starfish gonads look like exactly, but scientists tell me that their gonads spill out and they die in a matter of hours. Did you watch our video? It's one of those things that's hard to believe unless you see it firsthand.

Any of the current hypothesizes circling around have to do with a pathogen carried potentially by invasive species to the region? With the Fukushima event in mind, are there any other probable causes you can conclusively rule out?

Debris from the Fukushima nuclear disaster has been washing up along the west coast and that has certainly raised concerns that invasive species may be hitching a ride on them. So it's possible that this could play a part, but scientists have pointed out that there have been some large chunks of Fukushima debris on Oregon's coast, but Oregon has largely been spared from the sea star die-offs. It's just been reported at one site in Oregon.

if you have a bit of time, there is a good video from Vancouver Aquarium talking about what we know it isn't... http://www.vanaqua.org/learn/see-and-learn/live-stream-archive/sea-stars-dying it explains a bit about how the surface of a seastar is similar to us in the sense that it is always covered with a host of stuff (sometimes referred to as sea slime) from bacteria to viruses to viruses that infect bacteria, etc... and narrowing down what is most prevalent in the symptomatic starfish is not as easy as it sounds. Its hard to know if what is hurting them is something that is normally in sea slime and some other factor or pathogen is making them more susceptible.

Wow that's looks very ... academic! One question: the description in the above video notes "extremely overpopulated sunflower sea star populations" -- could this die-off be a good thing?

Some have characterized this as a potentially good thing in areas where starfish have overpopulated. Others have even said, "Maybe this is the starfish's way of population control." But I asked sea star expert Chris Mah whether the die-offs could be the starfish's way of managing population and he said, "There’s no internal clock that causes animals to die on their own. The sustainability of a population may exhaust itself when it uses up its resources, but a disease is not the inevitable outcome."

As for other possible causes.... Die-offs have been linked in the past to low oxygen levels in the water and environmental toxins entering the water through local runoff. Yet this seems unlikely to be the cause in this case because these low oxygen and environmental toxins would normally impact a wider array of animals, not just sea stars.

Marine die-offs in the past have also been linked to larger environmental factors like climate change and ocean acidification. Warming waters and changing pH levels can weaken the immune systems of marine organisms including sea stars, making them more susceptible to infection.

That's an interesting point. A lot of people have have been asking about Fukushima-related radiation, but not invasive species from tsunami debris.

So far debris from Japan has reached the west coast and that has lead to potential invasive species almost been introduced, but from what I understand these invasive species have been captured and stopped. If any of those species got a foot hold, things could get ugly. And from what scientists tell me, they're more concerned about invasive species traveling on tsunami debris than radioactive material.

How can anyone state conclusively that all potentially invasive species have been captured and stopped? That doesn't seem possible?

I guess I should say that so far there isn't evidence that an invasive species has from tsunami debris has taken ahold here and is wrecking havoc.

I read the title of an article the other day on /r/worldnews which stated that killer starfish are becoming a problem in the Great Barrier Reef. Are these killer starfish also suffering from this strange syndrome or is it just a particular species limited to the Pacific Ocean?

As I understand, the killer starfish (aka crown of thorn starfish) are not impacted by these die-offs. So far sea star wasting syndrome is impacting about a dozen different starfish populations, including: Pycnopodia helianthoides (sunflower star), Orthasterias koehleri (rainbow star), Pisaster brevispinus (giant pink star), Pisaster giganteus (giant star), Evasterias troschelii (mottled star), Pisaster ochraceus (ochre star), Solaster stimpsoni and dawsoni (sun stars), Dermasterias imbricata (leather star), Mediaster aequalis (vermilion star), Leptasterias spp (six-armed star), and Patiria miniata(bat star).

My scarce understanding of this is that the arms walk off in different directions, pulling the starfish into pieces. So what do the arms do, once they're off? Just a continuous march in the direction they started in? What stops them from regrowing into a new starfish?

Many viewers have asked whether starfish can regenerate a new body from a leg that walks away, but in this case the starfish are dying too quickly so they don't have a chance to re-grow body parts once they've ripped themselves apart. Their insides spill out and they die within a few hours.

So the video says the sea floor is littered with dead starfish, are there any species taking advantage of the sudden banquet, or are the diseased starfish dangerous to eat?

That's a good question. We have video of a healthy looking starfish eating dead starfish. This something that scientists are looking into further -- can this syndrome be passed by consuming flesh of an infected species? (Kinda sounds like zombie starfish!) They don't have the answer to that question yet.

Ah, might be like Kuru in some ways?

Do starfish attempt to eat their own wayward limbs? God, what a grisly disease, imagine it in vertebrates of whatever sort. Thanks for the AMA.

From what I've seen once they start ripping themselves apart, they don't have much time to do anything else (like eat their own wayward limbs). Here's another disturbing time-lapse video from the Vancouver Aquarium of a sunflower star ripping itself apart over 7 hours. Thanks for joining in the conversation!

One more question! Any idea why 'wasting disease'? Wasting brings to mind emaciation, why not 'ripping desease' or something?

That's an interesting point. I think the term has to do with the stars "wasting away" to nothing in a short period of time. Here's more info about the syndrome: http://www.eeb.ucsc.edu/pacificrockyintertidal/data-products/sea-star-wasting/

As the sea stars are integral members of the marine ecosystem and a large die off could upset the natural balance of these systems, what are the possible consequences and how bad could things get?

The loss of this many sea stars could fundamentally change the biodiversity of the seascape because starfish are such voracious predators. Eliminating them sets off a chain reaction. We really don't know how bad things could get. The die-offs are continuing to happen. They don't show any signs of stopping in the near future. However, because the die-offs are patchy at this point, scientists aren't worried that the sea stars will be wiped out entirely. Starfish are free-spawners (meaning their buoyant eggs and sperm are simply released into the water) so if we continue to have patchy die offs and not all populations are obliterated, then it’s reasonable to think that starfish populations could rebound from starfish left unaffected by the syndrome.

Are you familiar with the radiation studies that were done in the 1970's and 1980's that discovered a massive impact on starfish immune systems when exposed to a minor amount of radiation? In particular they were concerned with radioactive waste disposal done in the pacific from the 1950's through the early 1970's.

I'm not familiar with those studies. Feel free to share links here. Thanks.

Is this happening elsewhere? If not, will it begin to spread to other oceans?

Sea star wasting has been reported up and down the Pacific shores of North America, as far north as Alaska and as far south as San Diego. Wasting has also been reported at some locations on the East Coast of the U.S. off the coast of Rhode Island and North Carolina. But researchers say until they’ve identified the cause of the West Coast die-offs, they can’t confirm any connection between these outbreaks. The die-offs are continuing and it's not clear where/when it will end.

This might be a little out of left field but when I read that starfish are dying in droves I can't stop to wonder about our little honeybees too. I know they are VERY different, but are there any similarities between how the starfish are dying and bees?

That's an interesting question. I don't know that anyone has made any links or comparisons between starfish die-offs and honeybee die-offs.

Is it possible that the disease is coming from one of the starfishes food sources? Are they testing for them?

I believe this is one of the more recent possibilities that they're looking into.

How does your research effect my day to day life... (politely asking, why should I care?)

You sound like my editor! ;-) First, Water is literally is the life blood of a sea star. They are really sensitivity to any changes in salinity and water quality. Toxic materials of any kind could conceivably affect them. So they’re the canary in coal mine and when they're dying by the tens or even hundreds of thousands, it's an indication of something being out of whack in the marine environment. Second, Sea stars are voracious predators, like lions on the seafloor. They gobble up mussels, clams, sea cucumbers, crab and even other starfish. That’s why they’re called a keystone species, meaning they have a disproportionate impact on an ecosystem, shaping the biodiversity of the seascape. When a predator species is removed, the prey species can take over and go wild and they end up overgrazing .... it can end up reducing the overall biodiversity of an area. If this die-off goes global, this is a huge shift in the biodiversity in the oceans and it's at least important to be aware of that.

Scientists put starfish showing symptoms in tanks with starfish not showing symptoms but from the same area. The apparently healthy starfish died, but no faster than if they were in a tank without sick ones. Does this mean literally all of the starfish collected died? Have they not found any resistant to the syndrome?

Also, have they put starfish from other areas (perhaps other countries) which haven't yet had die-offs in tanks with sick starfish? Assuming it is a pathogen it would be important to know if any other starfish have resistance to it.

Lots of tricky questions here. I'll do my best... There are about 1,500 species of sea stars, and so far about a dozen species are impacted by this disease, so it's not that all of the sea stars are dying from this syndrome. That's a good question about putting starfish from unaffected areas in with affected ones -- as I understand an experiment like that is in the works. However, I know that scientists want to be very careful not to bring the disease to areas that aren't impacted by the syndrome yet.

Okay, so plenty of other species of sea stars haven't been affected yet - but does the fatality rate appear to be 100% in the species which are affected?

No, that's another thing that's so strange about how this syndrome is moving around. A bunch of sunflower stars die in one place and a miles away, they're doing okay. It's not clear if the "pathogen" just hasn't reached that place yet or if the currents are keeping the water "fresh" in that area or if those starfish aren't as susceptible for some other reason (i.e. maybe the water quality is better there).

As someone with no knowledge of Marine Biology, do you see any correlation between this and the Oarfish randomly showing up in shallow waters off the Pacific Coast?

You know, I haven't thought to make that connection and none of the scientists I've spoken with have brought it up.

I watched a documentary on the mass beachings that said they believed that it was caused by sonar experiments with the Navy. Is there a possibility the star fish are suffering the same fate or is it just hocus pocus?

As far as I know there's no correlation between where sea stars are dying and where the Navy does sonar experiments. Marine mammals, however, have been shown to be impacted by sonar tests. Here's a recent story that might be of interest about the Navy renewing permits for bombing and sonar exercises: http://earthfix.info/flora-and-fauna/article/navy-looks-to-renew-permits-for-bombing-and-sonar-/

Is Cthulhu involved?

Thanks for making me google that. ;-)

Thank you for the AMA. I was wondering if there is any connection at all to the leaked radiation from Japan. Have the currents brought enough radiation this far to make this kind of die off impact?

The short answer is almost definitely no. Scientists do not see a connection between the massive die-offs of starfish along the Pacific shores of North America and Japan’s Fukushima nuclear disaster. Here are some reasons why: No. 1 Recent tests for radiation in seawater along the west coast have found “no detectable Fukushima cesium.” While small amounts of radioactive have reached the west coast, the largest concentration of radioactive water released during the nuclear meltdown is still moving across the Pacific. Scientists predict that the radiation plume will reach the west coast of the United States by around April 2014. No. 2 The die-offs are patchy. This doesn’t line up with a giant plume of radiation moving across the Pacific. They’re popping up in certain places like Seattle and Santa Barbara and not in others, such as coastal Oregon, where there’s only been one report. No. 3 Sites closer to the Pacific shorelines are being affected sooner than places farther out to sea. And there have not been reports of starfish die-offs in Hawaii or Japan. If Fukushima were the cause, it would stand to reason that starfish closer to the source would also be impacted. No. 4 Sea star wasting syndrome predates the Fukushima nuclear disaster. Some of the earliest accounts of sea star wasting took place in the late 1990s. The Fukushima nuclear disaster happened in March 2011. More details in this article I wrote

How are starfish ripping themselves apart?

If they are just ripping off arms that contain part of the central disc, are they actually reproducing?

Could this be a new form of "budding" starfish are using to repopulate?

Please see this question: http://www.reddit.com/r/IAmA/comments/1yt9fb/why_are_starfish_literally_ripping_themselves/cfnmeen

And this question: http://www.reddit.com/r/IAmA/comments/1yt9fb/why_are_starfish_literally_ripping_themselves/cfnqh4i

have scientist tried putting sick and healthy starfish in the same tank to see if it really acts like a"zombie" disease after they eat each other ? or if its passed by being close to one another ?

I understand an experiment like that might be in the works, feeding body parts from sick ones to seemingly healthy starfish. I don't know anything beyond that.

Have you seen the phenomenon in a lab/aquarium with a previously infected organism? What's the physiologic mechanism that drives the one leg in the other directions past structural damage feedback points?

I know that aquariums up and down the west coast have seen die-offs of starfish in their tanks and the commonality between them is that they brought in water from the Pacific, so that's something that's being taken into consideration as well. And regarding your second Q, I don't know.

Why do the scientists in the video you provided seem convinced that it's caused by a protozoa, virus, or bacteria? It almost seems like a disorder of the nervous system of the star.

How this syndrome takes shape in starfish and moves from place to place acts most like something caused by a pathogen, or some kind of infectious agent. They're not ruling anything completely out at this point, but they're first exploring the most likely avenue.

from 3:29 in the video:

The arms crawl in opposite directions until they tear away from the body and their inside spill out

Holy fuck that's creepy. Is it normal that a single arm on a starfish crawls away and then regrows?

Are there any signs that this disease is spreading to other species? Like crabs?

Many have asked whether starfish can regenerate a new body from a leg that walks away, but in this case the starfish are dying too quickly so they don't have a chance to re-grow body parts once they've ripped themselves apart. If you want to see more creepy starfish ripping apart video, check this out time lapse from the Vancouver Aquarium: http://www.youtube.com/watch?v=mjrp3Eckr-E

I have to do a quick interview. I'll be offline for the next 30-40 minutes. I'll continue to respond to questions after that. Thanks for all the great questions!

What are the promising research paths in front of your team right now if any?

A network of scientists on both coasts received rapid response funding from the National Science Foundation to investigate the die-offs. It’s one of the fastest-ever mobilizations of research around a marine epidemic. Diver Laura James and I have been following the infectiousness experiments that they're conducting here in Puget Sound. They're also taking samples from both healthy and dying starfish up and down the west coast to send to a lab at Cornell University. They're using DNA sequencing and metagenomics to analyze the samples for viruses as well as bacteria and other protozoa in order to pinpoint the infectious agent among countless possibilities. It really is like a matrix, but from what scientists are telling us, they're may be homing in on a pathogen. The scientists will have their findings peer-reviewed before they make an official announcement. But we're expecting to learn something in a few months. Laura and I will be sure to follow up.

How quickly is this escalating? Is this "disease" becoming a growing chain reaction that is constantly expanding?

That's tricky to answer because it relies on people like DiverLaura being out keeping a constant eye on starfish populations. Divers in Puget Sound have done an amazing job of trying to keep tabs on how the syndrome is moving from place to place, but it's they can't be everywhere at once.

Why are starfish literally ripping themselves apart off the Pacific Coast?

A network of scientists on both coasts received rapid response funding from the National Science Foundation to investigate the die-offs. It’s one of the fastest-ever mobilizations of research around a marine epidemic. Diver Laura James and I have been following the infectiousness experiments that they're conducting here in Puget Sound. They're also taking samples from both healthy and dying starfish up and down the west coast to send to a lab at Cornell University. They're using DNA sequencing and metagenomics to analyze the samples for viruses, bacteria, other protozoa in order to pinpoint the infectious agent among countless possibilities. It really is like a matrix, but from what scientists are telling us, they're may be homing in on a pathogen. The scientists will have their findings peer-reviewed before they make an official announcement. But we're expecting to learn something in a few months. Laura and I will be sure to follow up.

Is the starfish problem localized to wild starfish or are captive starfish also experiencing this?

yes, aquariums have reported starfish dying in their tanks as well.

Well, why are they?

See answer to question below.