Pycnopodia Watch! Cautious Optimism about Sunflower Stars!

The Starfish Wasting Disease was first documented on the west coast of North America in 2009 and began to hit really hard in 2013 as I blogged about here and it became suddenly noticeable by MANY scientists on the west coast from Canada to California.  Due to a massive population explosion there followed a catastrophic die off in British Columbia which I documented here, with pictures courtesy of Jonathan Martin. 

In the intervening years, the Starfish Wasting Disease "event" had taken on a HUGE stage. UC Santa Cruz now monitors the health of west coast asteroids on their website (here). 

The first Sea Star Wasting Symposium was held earlier this year in Seattle. A meeting which I attended and reported on here. 

Perhaps one of the most significant losses following the massive starfish wasting disease epidemic that hit the west coast of North America (and possibly parts of the east coast) was the apocalyptic loss of the iconic sunflower sea star, Pycnopodia helianthoides.

When I was growing up on the west coast, there were sunflower stars that were HUGE!!  Tall tales would  report them reaching two and a half, then THREE feet across! But most were a good dinner plate size.

These animals were voracious predators and for starfish, moved quickly across the intertidal and subtidal...

Sunflower Stars are an ecologically important species. 

Unfortunately, populations of this species were DEVASTATED by the starfish wasting disease epidemic. More so than almost any of the other species, the sunflower stars were more often than not, completely removed from local areas along the coast.

Ecologically this has had VERY significant ramifications. Recent ecological studies, such as this 2016 paper in PeerJ by Schultz et al   have indicated that green sea urchin abundance in British Columbia has increased FOUR FOLD!

This has agreed somewhat with anecdotal observations by naturalists on Twitter observing sea urchin abundance in California...

Ever since the disappearance of Pycnopodia sea stars, the purple urchins have become very common - coincidence...? pic.twitter.com/LohVivn8YJ

— M. Sid Kelly (@MSidKelly) June 12, 2016

The exact reason is not clear. Possibly because the sunflower stars are not around? and the animals have just come out of hiding? Or have the stars been controlling the population structure of the urchins?  But it DOES seem to be related to the absence of the once abundant and mighty sunflower stars.

But Sunflower stars are also an ICONIC species..

In addition to be an ecologically important part of the intertidal and subtidal ecosystem, there's a lot to be said for how they really represented the North Pacific. Pycnopodia is an endemic, found nowhere else in the world.. and was often used as an example of the special and diverse fauna on the west coast of North America..

Some of the individuals which had been on display in public aquaria died within days. Some of these individuals had been around for over 20 years. Suddenly? Gone.

Those of us who are most familiar with the West coast fauna.. divers, naturalists, scientists, citizen scientists, beach goers, students, fishermen, anyone with an intertidal or subtidal ID guide was suddenly NOT seeing this species. It was and still is a significant and sad loss.

And so.. observations of THIS species have had a SPECIAL significance..

BUT today, a colleague of mine, Ms. Brenna Green observed THIS. A juvenile Pycnopodia helianthoides in Northern California!! According to her, one of the first she's seen in a good long while!!

A small individual. Only a few inches across. But still...

I was directed to iNaturalist which has been monitoring observations of ALL asteroids on the west coast.. There were only 60 observations of Pycnopodia since 2014!!- so only about 20 per year that are reported  Note also-some of those observations were from areas that are distant from the primary Sea Star Wasting Disease areas (such as Alaska).

Make no mistake, that's a very low number... but surprising considering that they were considered completely gone from some areas..

But they ARE still out there. And are still popping up..

An anecdotal skim of Flickr and Twitter shows that small sunflower stars have been popping up over the last year or so...
From Titlow, Tacoma, Washington from February 29, 2016

Weir's Beach, British Columbia by Laura Verhegge (taken April 21, 2015)

Recent accounts (such as this one) have documented a resurgence in populations of sea stars hit by starfish wasting disease (based on this paper).

But I would like to think that is SOME good news, even if this doesn't mean a full and immediate recovery..

Another significant issue? SIZE of the observed individuals

Lots of juvenile sunflower #seastars observed this weekend at Mystic Beach! #BritishColumbia #pycnopodia pic.twitter.com/Z6Zx0qtaym

— Jackson Chu (@jwfchu) June 7, 2016

Here's one of the most critical parts of these observations: Most are consistently SMALL. Many of the "adult" individuals we were used to encountering were easily dinner plate size or larger have not really been encountered.. or if so, not regularly. 

Are the small sized ones a sign that they simply grow very slowly?  Or more ominously,  do they die as they reach a certain size??

On the upside, I have heard SOME anecdotal observations of adult (~40 cm) sized individuals being seen in Washington and in other localites...

Stay tuned! Research continues. 

In the meantime, for further news check out:

Ian Hewson's Invertebrate Disease Blog:  https://seastarwastingdisease.wordpress.com/2016/06/23/adventure-continues-2016-international-parvovirus-workshop/

UCSC Starfish Wasting Disease Page: http://www.eeb.ucsc.edu/pacificrockyintertidal/data-products/sea-star-wasting/

Monitor Pycnopodia on the west coast at iNaturalist! http://www.inaturalist.org/observations?d1=2014-01-01&d2=2016-07-06&place_id=any&project_id=1360&taxon_id=47674&verifiable=any