Pacific Northwest
Bellingham Bay, WA
In June of 2013 on the outer coast of the Olympic National Park, a marine ecologist with the National Park, Steve Fradkin, made a startling observation as he found his way to one of the four sea star sampling plots that he had been surveying periodically for the past five years.
The moment he arrived at the first plot that June, Fradkin knew something was off. Many of the stars had gooey-white lesions across large patches of their skin. Some were missing a limb, or two or three. Disembodied arms crawled around the rocks by themselves. Other stars had fallen apart altogether, their melted carcasses scattered about the plot.
“It looked pretty much like a horror show,” Fradkin said, describing the mess.
Thus began the search for the cause of what turned into a marine epidemic (epizootic) of Sea Star Wasting Syndrome/Disease. This epidemic has taken between 80 and 100% of some species of sea stars from the Eastern Pacific shores of North America spanning the coast from Baja California to Alaska.
More circumscribed outbreaks of a similar syndrome have flared up periodically in California. They came and went, maybe associated with water temperatures from el Nino. But the cause was never definitely determined and it is was never like this one. Here the geographical span, the number of species affected, and the total devastation of some species had not been seen before. This one was different.
A couple of previous buckets have illustrated the devastation and suggested resilience of the West Coast’s sea stars three years ago, one by Ocean Diver, and one by me. This diary is an update of the ongoing research and monitoring of the toll it has taken on these iconic sub-tidal and inter-tidal critters that are favorites of children and adults alike at the sea shore. We hope for their full recovery.
Since our previous reports some new light has been shed on the causes and the breadth of this marine epidemic. The causal factors are not totally clear at the this point but probably involve multiple and cascading chains of events coming together. Further, different causal factors might be operative on different species and at different locations.
The Stars
Although at least 22 species have been identified as being affected, they vary greatly in the degree of susceptibility to, and severity of the disease. Three of the most highly affected species are among the more prevalent stars in this area and most study has focused on them thus far. These three species are described below.
Sunflower Star (Pycnopodia helianthoides), is one of more attractive stars sporting various bright colors from yellow, orange, red, purple. They are also one of largest of the sea stars, growing up to a meter in diameter. They begin with only about five arms but eventually grow up to 24. They are considered a keystone species and are major predators of the subtidal bottom, dining on urchins and bivalves among other critters. Rarely showing themselves in the intertidal areas they are not often seen by the casual beach comber.
The sunflower star has suffered the greatest losses through its range where studies by divers and by trawling nets show a decline of between 80%s and 100% losses in various locations. Such drastic losses of keystone species to the local marine environment can be disastrous for the biodiversity and sustainability of the near shore marine environment.
Ochre Star (Pisaster ochraceus), have also sustained severe losses in some of its natural range from Californa to Alaska. Ocher stars are found largely in the intertidal zones and thus are readily observable to beach combers at low tides. They are relatively stocky, have five arms stretching to about 10” in diameter. Ochres too are considered a keystone species in the intertidal and subtidal environments and like the Sunflower, they prey upon urchins.
Although their name “ochre” describes some of them, many are also purple as seen in the lead photo. Another common name for them is the “purple star.” In more protected waters such as the Salish Sea and its bays, they are more purple while on outer exposed coast, their colors tend to be more orange or brown (i.e. ochre). And then there are some that distribute these colors within a single star. This is one of my favorites.
Mottled Star (Evasterias troschelii) is also among those affected by SSWD but less so than either ochre or sunflower. The mottled star has a smaller body than the others but its five arms are longer than the ochres, reaching 11” in diameter. They too feed on bivalves and various shelled creatures.
In some areas where the other two stars have been severely impacted, the mottled star’s numbers have increased and it is thought that it might eventually displace the ochres in those areas.
Multi-Agency Rocky Intertidal Network (MARINe)
Much of what is known about the marine ecosystems along the North American Pacific shore over the past 30 years owes to the work of MARINe, a research center at University of California Santa Cruz. This is a multi-agency consortium of some 18 research groups that coordinate in maintaining large ongoing monitoring of intertidal biodiversity at 130 sites from Baja California to Alaska. Thanks to them there exists long term data on coastal populations of both plant and animal life that are available to track the extent of epidemic outbreaks such SSWD.
When the first alarm bells were sounded as noted in the introductory paragraph, it was from one of their study sites on the Olympic Peninsula Coast. MARINe was on this this epidemic from the very start and facilitated much of the research. Also, with their coordination they have organized a large cadre of citizen science observers. These citizens, including Ocean Diver and myself, monitor and report on the state of the stars at specific beaches throughout this region.
The photo below is the beach that I monitor during spring and summer low tides. As you can see, it is an urban beach on the shores of Bellingham Bay..
The Syndrome:
Sea stars with the wasting syndrome virtually waste away. Initial symptoms include lethargy and arm curling after which white lesions appear and spread over their bodies. They appear deflated and often one or more arms will fall off. These loose arms may become autonomous such that they will literally walk away from the main body. Wasting typically continues until they dissolve into a blob of goo.
Once the syndrome has begun, the star typically disintegrates within three or so days. One of researchers with whom I consulted thought it might more descriptively be called Sea Star Melting Syndrome as indeed that is what they do. Apparently some can survive after contracting the disease in the wild but thus far, none that contract the disease in the lab are documented as surviving.
The first two photos below are of a newly diseased ochre that I observed on August 19, 2020 showing that the disease is still with us here in Bellingham at the edge of the Salish Sea.
When a star loses a limb and it remains viable, the limb is capable operating on its own such as walking off as it has a contained nervous system. The main animal is capable of regenerating its lost arm over a year’s time. Being capable of asexual reproduction, one starfish can create another one without mating. A given severed limb, if it contains sufficient organs, can regenerate an entire body that becomes an entirely new star. Some species of starfish can detach their own arms without injury with the intention of reproducing. We will never know for sure what happened with this star but in any case if it survives, there is a distinct chance that this 4 armed sea star might yet end up with five.
As a preview of the next episode, I will suggest that there are many contributing and or causal factors, some known and some not known, of this condition. Further, it is appearing likely that this is not a single disorder. I’ll try to clarify in part 2.
Oh, and just to confuse matters more, one of the main researchers, proposes that the name SSWD be changed to : Asteroid Idiopathic Wasting Syndrome (AIWS). Just when we thought we had enough acronyms. Reasons for this suggested change will become clearer in part 2 where I will address the consequences of this disease or syndrome and what is causing it.
Stay tuned.
