After a looong prop plane ride Elliot and Ian arrived in Dutch Harbor, Alaska, where the team had previously performed work in April 2015. Back then we’d taken 80 samples to see if the candidate virus involved in the disease, SSaDV, was present. At the time there was no disease observed. The flight out was pretty incredible – lots of scenic volcanoes as we passed Unamak Island and the Alaska Peninsula.
After the usual hair-raising (albeit it was less so this time – light winds) landing at Unalaska Airport, we quickly checked into the hotel, and immediately went into the field in search of sea stars. It didn’t take long – a low tide revealed numerous very healthy looking Evasterias troscheli in waters adjacent to the hotel!
In addition, we could see very large numbers of small urchins – probably Loxechinus sp. – and in deeper waters could make out several large (~ 28″ diameter) Pycnopodia helianthoides – another target of our work.
Next, we went to a site called “Little South America”, named so because it resembles the south american continent on a map. We’d previously seen many sea stars in shallow waters off the boat ramp. This time, it was the same story – quite a few! However, we did notice three which were in rough shape – all three were very flat, one had its guts hanging out on it’s underside, and another seemed to be losing legs. All three were actually on the ramp itself, whereas all the others looked fine and happily eating bivalves. We also noticed a lot of chemical contaminants in the water – oily slicks from the boats. Given their location, we hypothesize that either the deflated ones had been run over, or that they were being affected by oils. We’re going to have a look at more stars that were reported by our colleagues out here near docks that appear disease.
From Little South America, we went for a drive to our furthest sampling site, Little Priest Rock, which is located about 3 miles outside of town. After a hunt we found a couple of sea stars, notably Leptasterias hexactis, the 6-armed star, and one Solaster stimpsonii, the rainbow star.
Sea stars are not common out at Little Priest Rock, since it’s higher energy than the other sites. Still, gratifying to see some sea stars here. One notable absence was the bloody henry star Henricia ornata, which was present in April when we were here last.
After a quick trip over a scenic peak south of Dutch Harbor (amazingly gorgeous views), we proceeded to our next site, Ballyhoo, where there had been some reports of wasting over the last couple of months.
At Ballyhoo we saw numerous other sea stars, most of which were happily engorging themselves. Here also we saw a few stars with what looked to be physical injuries, and at least a couple with some white slime. A big challenge with this disease is distinguishing between the disease and either physical or chemical lesions. Since the vast majority of stars appear perfectly fine with only a couple showing any signs we think that these are not suffering from wasting disease, but we will take samples to confirm the presence/absence of SSaDV back in the lab.
So today we are off with collaborators out here, Melissa and Josh Good, on a boat ride in the morning to see some far-off sites, and then in the afternoon the divers will be in the water to collect sea stars. With plentiful sea stars, we should meet our goals. One challenge will be to find small-ish stars – fitting a 36″ Pycnopodia in our shipping containers isn’t an option – but we will do what we can. Stay tuned for more adventures!