The past few days have been a blur. The weather turned south on us (or I guess that saying should be ‘from the south’ as that is where the big storms come from here) o 50 n Tuesday night. Guests were overknots and the visibility dropped to <25ft. We were shooed out of the lab since it was likely to set in for the night and reach ‘ condition one’ which means we cannot leave the building we are in. There are not great places to sleep in the lab so an early night to bed sounded like the way to go.
During the day however, I was able to find a solder that had come loose and had been plaguing some of the sensors that I use to measure oxygen. After taking apart the wire, discovering the broken connection and asking the instrument technician here to solder it for me (being far better at soldering than I), we all of a sudden have three backups for our very delicate oxygen sensor. Life is better.
We then snuck out in, what can only be called, bad weather to put in our new dive hole. The wind was blowing strong and while it was ‘warm’ at -16 C the wind chill was down to around -51 C. Rory and I were doing much better than the drill operator who had no choice but to sit face into the wind for around an hour. We dove the site the following day and while an amazing location the worms that we were after were not there either (the photo at the beginning and end of this post are from that dive). We have decided to spend our time from here on out looking at the community that we know where it is (the jetty) and abundant while the others remain… somewhere.
Anchor ice is a prevalent occurrence in McMurdo Sound. Anchor ice forms on pretty much anything in shallower water and as soon as one piece forms it acts as a nucleus for more ice to form. As this continues it is the equivalent of someone blowing up a balloon very slowly (as ice is less dense than seawater) and it floats up to the surface, killing the animal that it attached to. That’s one reason we don’t work shallow here – the ice constantly disturbs shallow communities but occasionally it extends deeper down. This particular example of anchor ice is growing on a sponge (Homaxinella balfourensis) at 70ft deep. The deepest I have ever seen it. Normally it peters out around 40-50ft and very rarely goes as far down as 100ft.
The other neat thing about the site was that there was an incredible abundance of octocorals blanketing the seafloor making it look like snow everywhere. This dive really reminded me why I love diving in the Antarctic. Even in this time of year when there is so little light, the diving is much better than the training dives we did in Oregon to get ready for this trip.