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5

Since my earlier posts on Pisaster wasting disease in the lab, I've been contacted by a couple of divers who have seen afflicted stars on their dives in Monterey Bay. They have both graciously given me permission to post their photos, which clearly demonstrate that Pisaster and other stars are being stricken subtidally as well as intertidally and in the lab.

This set of photos is from Ralph Wolf, taken on 11 October 2013 off of Pacific Grove, California.

This star, a Pisaster giganteus, looks healthy.  It has no dermal lesions, the body is plump and full, and the arms are lying flat and fully attached to the rock.

An apparently healthy Pisaster giganteus
Pisaster giganteus
©2013 Ralph Wolf

This P. giganteus, on the other hand, is doing the twisty arm thing that I saw in the lab. It seems to be the precursor to the star ripping its arms off. There's an orange Patiria miniata lurking in the background, just waiting for a chance to begin feasting on a not-quite-dead-yet sick star.

Pisaster giganteus ©2013 Ralph Wolf
Pisaster giganteus
©2013 Ralph Wolf

Here are some more extreme examples of the twisty arm thing in P. giganteus that have already resulted in at least one arm being autotomized.

Pisaster giganteus
©2013 Ralph Wolf
Pisaster giganteus
©2013 Ralph Wolf

And it wasn't just a few isolated Pisaster stars that were showing early signs of the disease. Here are three of them on the same rock, all twisting their arms to some degree.

Pisaster giganteus ©2013 Ralph Wolf
Pisaster giganteus
©2013 Ralph Wolf

Pisaster stars were not the only ones that Ralph saw stricken with the disease.  The sunflower stars, Pycnopodia helianthoides, were in even worse shape. This star has contorted itself into an almost recognizable shape and lost at least a few arms, one of which is visible at the top of the photo.

Pycnopodia helianthoides ©2013 Ralph Wolf
Pycnopodia helianthoides
©2013 Ralph Wolf

And take a look at this poor star. All that remains is the central disc and a single arm. Given that Pycnopodia normally has 20-25 arms, this animal has suffered a huge loss:

OLYMPUS DIGITAL CAMERA
Pycnopodia helianthoides
©2013 Ralph Wolf

And, of course, there were Pycnopodia arms crawling around by themselves. They literally don't know they're dead.

Pycnopodia helianthoides arm ©2013 Ralph Wolf
Pycnopodia helianthoides arm
©2013 Ralph Wolf
Pycnopodia helianthoides arm ©2013 Ralph Wolf
Pycnopodia helianthoides arm
©2013 Ralph Wolf
Pycnopodia helianthoides arm ©2013 Ralph Wolf
Pycnopodia helianthoides arm
©2013 Ralph Wolf

Ralph was able to find and photograph some apparently healthy small Pycnopodia stars.

Pycnopodia helianthoides ©2013 Ralph Wolf
Patiria miniata (left) and Pycnopodia helianthoides (right)
©2013 Ralph Wolf
Pycnopodia helianthoides ©2013 Ralph Wolf
Apparently healthy Pycnopodia helianthoides
©2013 Ralph Wolf
Pycnopodia helianthoides ©2013 Ralph Wolf
Apparently healthy Pycnopodia helianthoides
©2013 Ralph Wolf

The rainbow star, Orthasterias koehleri, was also getting in on the action. These are beautiful stars in bright reds and oranges:

Orthasterias koehleri ©2013 Ralph Wolf
Orthasterias koehleri (top) and Patiria miniata (bottom). Pisaster giganteus in background in lower right corner.
©2013 Ralph Wolf

But Orthasterias is also twisting and autotomizing arms:

Orthasterias koehleri ©2013 Ralph Wolf
Orthasterias koehleri
©2013 Ralph Wolf
Orthasterias koehleri arm ©2013 Ralph Wolf
Orthasterias koehleri arm
©2013 Ralph Wolf

So, for now the disease continues to exact its toll. At least this time it appears that Patiria miniata (bat stars) and Dermasterias imbricata (leather stars) are not being sickened, although we have had outbreaks of a very similar disease in the lab that affected these species. And the fact that sick stars are being seen in the field, both intertidally and subtidally, means that the disease I documented in the lab is not strictly a captivity-related phenomenon. I think what we are witnessing is regional--the first report I read about was in British Columbia--rather than local. Only time will tell.

4

Today is Monday.

Last Friday morning I was at the marine lab doing my usual feeding and cleaning stuff, and everything was fine. I was back at the lab Friday afternoon to return some animals that we had borrowed for one of the classes I'm teaching, and as soon as I got out of the car I knew something was wrong. I could smell it. Plankton bloom.

When I opened the door to one of the wet labs, it felt like walking into a wall of stench. It is a peculiar smell of excessive fecundity, which we occasionally see at the lab this time of year, due to a rapid population increase, or "bloom," of one or a few phytoplankton species. I'm not sure if the smell is actually bad or if it just seems bad because of all the negative things I associate with it. Negative things such as:  Sludge accumulating and decomposing on any horizontal surface in a table, including the surfaces of animals; said animals being fouled and dying because their respiratory surfaces are gunked up; seeing water straight from the tap coming in brown.

But whenever we get a nasty bloom like this, I am always curious about which critter it actually is. Back in the summer of 2010 there was a phytoplankton bloom in Santa Cruz that was at least partially caused by a dinoflagellate in the genus Alexandrium, some of which are known to produce toxins that work their way up the food chain and cause paralytic shellfish poisoning in people.

I took a sample from some build-up from this current bloom and looked at cells under the microscope (fun!). I was able to identify a couple of dinoflagellates right off the bat.

This is Ceratium.  I saw a lot of cells that look like these:

Ceratium cells.
Ceratium cells.
© Kudela lab, UCSC

Various species of Ceratium are present in plankton tows most of the year and as far as I know are pretty innocuous.

I also saw lots of these cells, too. This is Prorocentrum, a dinoflagellate that is pretty easy to recognize because of the little spine at one end of the cell. I don't think these guys are toxic, either.

Prorocentrum cells. ©2013 Allison J. Gong
Prorocentrum cells.
© 2013 Allison J. Gong

Lastly, there were a lot of these cells. I wasn't able to get a very good look at them and don't know for sure who they are, but they may be a species of Cochlodinium polykrikoides. I saw single cells and chains of two cells. C. polykrikoides is not nearly as harmless as the other two algae I saw. It has been responsible for fish kills in Asia.

These cells in a short chain might be Cochlodinium polykrikoides. ©2013 Allison J. Gong
These cells in a short chain might be Cochlodinium polykrikoides.
© 2013 Allison J. Gong

On my way out of the marine lab yesterday I stopped by the overlook to see what the surf looked like. I could see that the water was discolored with a brownish tinge. Look at the water as it recedes from the rocky bench. It would normally be white, but here it is kind of a dirty gray-brown color.

The good news is that today, Monday, the bloom seems to have abated quite a bit. I cleaned all of my tables and tanks on Saturday (extremely gross) and Sunday (not nearly as gross) and this morning there wasn't very much sludge at all. And the smell was nothing like it had been on Friday afternoon. So maybe we're getting a reprieve and won't have to deal with weeks and weeks of this stuff. That would be nice. My poor animals need a break from environmental conditions that are trying to kill them.

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