A crucial part of our new project is understanding how SSaDV has changed over time and space. As part of our earlier study (Hewson et al., 2014, PNAS), we had investigated the presence of SSaDV in sea stars from 1923 to present day, by looking at museum specimens at the LA County Museum of Natural History. The new project seeks to expand this work, both in terms of geographic location of samples (most in our earlier work came from offshore Oregon or Northern California), along with temporal resolution.
On Thursday, Nov 6th, Ian traveled to San Francisco to interact with scientists at the California Academy of Sciences. In 2014, the CAS was crucial – although not directly involved in – our study of SSaDV, as they had a huge population of healthy sea stars which never got sick. Initially this was a bit of a mystery as it was very close to populations of dying sea stars, but soon we found out that they make their own artificial sea water, and, hence, there was no potential of exposure to outside pathogens like SSaDV. The CAS is also home to a huge collection of Echinoderms from areas not covered by those at the LA Museum of Natural History.
On Friday, Ian casually visited the Aquarium of the Bay, which is located next to the Fisherman’s Wharf in North Beach, San Francisco. There, he saw numerous very large specimens of Pisaster ochraceus, and a few Patiria miniata in their oceanarium. Interestingly, some did not look to be doing too well, which may be because the aquarium draws its water from the bay itself. However, many stars looked perfectly fine.
Healthy-looking sea stars in the Aquarium of the Bay – left is Pisaster ochraceus, right two are Dermasterias. Below the Pisaster ochraceus you can see a couple of Patiria miniata – there were definitely some which seemed to look a little withered.
After a bit of time off in San Francisco over the weekend, Ian worked at the CAS for the day Monday. First, he sampled 38 sea stars, from 1895 to the present day, from amongst their collection. This was made possible through the efforts of Chrissy Piotrowski, Rich Mooi, Kelly Markello and Rebecca Johnson – thank you again! The samples were chosen primarily from those collected in Alaska and around San Francisco, and were in various states of preservation. Ian sampled tube feet using sterile forceps, and then sent these back to the lab for analyses.
Interestingly, several of the samples appeared in rough shape. Whether these were indeed wasted from disease, or damaged during collection remains to be seen. The plan for these samples is to initially perform qPCR targeting a couple of genes on SSaDV’s genome to see if it was present (or at least a close relative), and then perform whole genome amplification using overlapping PCR, then to compare genome to genome to see how the virus has changed through time. These will be compared to full genomes recovered using the same approach from samples from different species and geographic areas in the present day disease event to figure out if there have been any major shifts that correspond to its emergence as a pathogenic agent. This is amongst the first uses of museum specimens for detection of a viral pathogen in historical specimens, and definitely amongst the first in any aquatic invertebrate. Museums represent hugely valuable resources for this kind of work.
Next, Ian gave a public seminar on sea star wasting to a group of docents, curators, and researchers, along with a few members of the general public. Although we are only a few months into the current project, we are starting to share plans for our future work, and expound of recent observations in aquaria. Some very valuable feedback always comes from these talks, and Ian received some very useful comments from CAS scientists.
Next, Ian traveled down the beautiful coast to Santa Cruz, where he pit stopped overnight before heading to Monterey, where he is slated to meet with Emma Fiori and Mike Murray of the Monterey Bay Aquarium. Last night, Ian (and his partner Zug, who came along on this adventure) went to a beautiful eatery in town, Restaurant 1833, where we feasted on some pretty amazing tucker. The house dates from the early 1800s (1833 actually!), and is apparently haunted. We definitely experienced some interesting noises and inexplicably opening doors. And, perhaps as a final creepy omen, we found this on a bookshelf. It’s been there for some time! So it looks like sea stars have been on people’s mind (perhaps even in the afterlife) for ages…
Next up, Ian travels to LA to work at the LA Museum of Natural History before flying home. Stay tuned!