Today Elliot and Jacob worked on checking nutrient levels in the tanks, which involves using an aquarium test kit of gauge ammonium, nitrate, nitrite, pH and salinity levels; everything is normal except for ammonium, which continues to be high. Ian and Jacob then performed a 40% water change with fresh seawater, and added in ammonium reducer. It worked! Ammonium levels went back to ‘safe’ concentrations; hopefully they stay low as biofilms begin to colonize filters.
This afternoon, Elliot decided to try feeding the stars again. Our first attempt with shrimp wasn’t successful – animals generally discarded the crustacean tissues. So, this afternoon Elliot tried a new food source, mussels from Wegmans (our local awesome supermarket).
WOW! Ru and Alaska, our two biggest Evasterias immediately picked up a mussel and attempted to open it. JAWS!
Since the stars are in rather poor condition, it’s likely they won’t be able to force the bivalve’s varves apart, so we shucked a couple of them and placed a small amount near each animal’s mouth to see if they’d take the bait. Amazingly, almost all the Evasterias did so!
Our Solaster stimpsonii are being a little more picky. In the wild they consume barnacles but prefer tiny sea cucumbers. So training them on another food source might take some effort. They are, however, rather animated, so I expect they’ll take to the new food soon.
Some other interesting news: Our collaborator, currently diving out on the San Juan Islands today saw almost no sea stars at all, where they had previously documented a lot. This is consistent with reports of sea star disease prevalence over the summer at Friday Harbor (Drew Harvell’s work), and anecdotal reports from elsewhere. Seems that the disease really has done a number on their populations. This of course complicates our work bit, since we’d hoped to secure Pycnopodia from the region, so we’re looking into new avenues by which to procure them.
Finally, Ian did an interview with KUCB (Dutch Harbor’s Radio Station). It made it onto the web and can be found here:
Tomorrow – I’ll be taking samples to see if our stars are free of SSaDV, as well as processing more that were sent to us from the New England Aquarium. Stay tuned!