Follow along as NG Grantee Rhian Waller explores the deep-sea corals that have been found in the shallows of fjords in Alaska, and discover what they can tell us about the rest of the ocean as well.
It’s the end of day three of our Alaska coral expedition, and so far all is going swimmingly well. Despite it being mid-winter here in Alaska, the weather couldn’t have been better – high 20’s out of the water and 36F in the water, glassy flat calm seas and beautiful snow topped mountains to boot. Visibility underwater isn’t quite what we’d hoped for, but it is 20-30ft+, which is more than we need to do our science, and more than enough to enjoy the scenery while you’re working.
To recap our whirlwind three days: We left the NOAA dock in Juneau at 6am on Thursday morning, bright and early and still in darkness. The trip down Stephens Passage, past the Taku Inlet (notorious for high winds) into Holkham Bay and onto Tracy Arm were thankfully uneventful; calm seas and a push from the tides meant we arrived in time to put in a dive that afternoon.
Sailing into Tracy Arm always gives me a thrill. The narrow fjord is bordered by 4000ft+ mountains, all covered in a dusting of snow with low-lying clouds hiding their true height. The rich aquamarine water gleamed as we turned ‘big bend’ and edged closer to our dive site. As we came around the corner to our sample site, it all came flooding back – the steep valley, the high walls, the mark on the wall that looks a little like a mermaid showing us where our study area begins – it was all there. We got ready to jump in.
Rolling backwards into the water from the skiff reminded me instantly this was winter. My gauge didn’t read more than 36F the whole dive. But there they were – our corals, dotted with fluorescent orange and green marker tape from previous visits and small yellow tags telling us who is who. The first dive was really a ‘look-see’, to check the conditions, shake down the gear and get into the groove; but the visibility was so good, and everything went well, we collected 10 samples right there the first day. And so went the second day – first dive 7 samples; second dive 12 samples; third dive 6 samples – pretty soon we’ll have all 38 colonies sampled for microscopic study and move on to other sampling tasks.
Today’s dives have been a little tougher. The day has been overcast, so the dives have been darker, making our three daytime dives seem like night dives (particularly our late afternoon dive). Along with some equipment failures and some high current on dive three (combined with a leaky mask!), we’re ready to start day four tomorrow fresh. On the good side we’ve finished our main sampling for histology and have moved on to collections for ultramicroscopy (I’ll be explaining the samples in a later post!), DNA and measuring our tagged colonies. Three more days to go, and we’re ahead of ourselves right now. Never speak too soon on expedition though; being ahead is a good place to be, as you never know what a new day brings when at sea!