This invited post is authored by Chris Mah, a Smithsonian National Museum of Natural History researcher. Chris is one of the world’s leading experts on starfish and echinoderms in general. He created and writes for Echinoblog, a one stop reading place for everything echinoderm. You can find him at Twitter at @echinoblog.

In September 2013, I broke the story about a mass sunflower starfish (Pycnopodia helianthoides) die-off in British Columbia. This developed into further accounts of Starfish Wasting ‘disease’ which is now recognized as “Starfish Wasting Syndrome” (because the nature of the causative agent is unknown) and since been reported from California and now Washington state.

The “disease” causes white lesions and tissue necrosis (death and decomposition), eventually resulting in arm loss and overall body collapse (the “wasting” part of the disease’s name). The disease has been observed in multiple starfish species but seems to have been noticed most heavily in sunflower starfish (Pycnopodia helianthoides) and ochre stars (Pisaster ochraceus).

Some have become concerned that there is a direct influence from Fukushima. Much of this seems unlikely. Deep-Sea News (among many other sources) have presented excellent reviews of data that can help the rational person make sense from some of the confusing deluge of misinformation.

Here, I continue this theme. Addressing a concern that has been brought up by many. But really, three simple observations discount any direct relationship….

Starfish Wasting Disease/Syndrome (SWD/SWS) pre-Dates Fukushima by 3 to 15 years. This is probably the most self-evident of reasons. One of the earliest accounts of starfish wasting disease was recorded from Southern California (Channel Islands) in 1997 (pdf). The account of SWS in British Columbia was first documented by Bates et al. in 2009, and their data was collected in 2008. Fukushima? March 2011. Starfish Wasting Syndrome Occurs on the East Coast as well as the Pacific. Many of the accounts alleging a Fukushima connection to Starfish Wasting Syndrome forget that there are also accounts of SWS on the east coast of the United States affecting the asteriid Asterias rubens. There is no evidence (or apparent mechanism) for Fukushima radiation to have reached the east coast and therefore the Fukushima idea is again not supported. No other life in these regions seems to have been affected. If we watch the original British Columbia Pycnopodia die-off videos, and the later Washington state die-off vidoes, one cannot help but notice that other than the starfish, EVERYTHING else remains alive. Fish. Seaweed, encrusting animals. etc.

the WA video

A survey of Washington state released recently. Note the sea anemones, algae, and crabs. All in apparent good health.

Viewing ANY of the pictures or videos from other accounts shows that only the sea stars are affected. If there were waves of Fukushima radiation pouring onto the coast-and “melting” all the starfish as some folks would suggest, EVERYTHING would be dead. Not just the sea stars. Note also that all the divers involved in these surveys have reported NO ill effects.

Unfortunately, we have no data on the actual agent that causes SWS. Within the grand realm of possibility there is always a (slim?) possibility there is a connection with Fukushima, but nothing we’ve seen gives us any reason to think that.

More Likely Reasons?

Speculation has suggested bacterial or viral sources. But invertebrate diseases can be complicated. The disease only seems to affect sea stars. Nothing else. This implies a biological cause with a very specific relationship. Possibly a bacteria or virus. But just as possibly some other type of infection resulting from a protist or fungi?

It also seems possible that it could be a disease similar to coral bleaching, where subcuticular bacteria of sea stars (as documented here) might be affected adversely. Or perhaps a combination? In conjunction with some environmental change, such as water temperature? The original series of papers by Amanda Bates indicated there was an association of the diseae with water temperature.

Our study of this event has just begun. Ongoing data collection and research have started. We shall see where it takes us…