Sunday, November 27, 2011

26 November – Flandres Bay

: The halo of light around the sun is caused by ice crystals in the clouds. Interestingly, one of my colleagues at Stony Brook (Prof. Daniel Knopf) just gave a seminar that discussed these features (he's an atmospheric chemist) right before I left NY for this cruise.

I live in Flanders, NY (a small hamlet on the east end of Long Island) which is why I particularly enjoyed our sampling location for our final day of science on this trip which is Flandres Bay, the southernmost bay along the Gerlache Strait. (and no, that's not a typo, it's Flandres).

Calm conditions are ideal for small boating, as well as making some very pretty pictures with the mountains and glaciers reflected in the water.

I've had the opporunity to conduct scientific surveys in this area 3 times in the past 18 months. Working with researchers at Duke University, we were here in May and June of last year (2010), then last year on our cruise, we were able to spend a day in the bay in December of 2010. So yesterday's survey was another data point (November 2011) in studying this unique environment.

 If you look closely at the edge of this piece of ice,  you can see tracks made by a penguin (or two).

We encountered a lot of brash ice and small icebergs on our way from the offshore station to the shallower bay, so when we arrived here we did a CTD cast and then launched two small boats. One (with me and members of my team in it) was conducting acoustic echosounder surveys in the waters of the bay which are too shallow for the large boat to work in. We lucked out with phenomenally great weather – no wind, sunny skies (too sunny for  a few folks who got pretty bad sunburns), and an amazing amount of scenery including icebergs, bergy bits, growlers, and other ice formations, some wildlife (a few penguins, a seal or two, and the other boat saw a minke whale!) in an otherworldly environment.

Our home for the past month, the Laurence M. Gould.
While we drove around “mowing the lawn”, the other boat was sampling small, juvenile krill that were hanging around in the water next to (and underneath) pieces of ice. These animals were E. superba that  were maybe a centimeter (~ 1/2 inch) in length.  Our acoustic surveys generally consist of parallel tracks spaced evenly apart (that's why we say we're 'mowing the lawn') – in our small boat in these conditions our tracks aren't quite parallel as we head mostly in a straight line but we drive around pieces of ice rather than push through them as we don't want ice to go under the zodiac and damage our prop or  echosounder.

: One of our crack team of acousticians, Scout Watson, makes sure that our echosounder is working properly and collecting information about krill patches as we survey the waters of Flandres Bay.

This would be an example of some ice floes that we would like to avoid as pushing our way through some of this would take a long long time.
 It's not just the ice above the surface that we have to worry about!  The submerged portion of the ice pieces can be just as dangerous to our gear. Luckily on a day like today, the water is clear enough that you can see the underwater portions of the ice and avoid them pretty easily.

Everybody in the science party got a chance to go out in the boat today, and some of us (myself, Paola, and Chelsea) were out for about 9 hours in total. It made for a very long day, but very rewarding as well. One of my secondary objectives on this trip was to visit Flandres Bay and return to a place that I call “Krill City” which was a spot nearshore on the southern edge of the bay where we found an enormous bottom layer of krill back in June 2010. Last time I was here, there was virtually no krill in the water column (according to our echosounder), but this year I saw a pretty good amount of krill swarms so that may be a sign that this is going to be a good year for krill – and possibly explain why it might not have been a great year for salps since we had such a difficult time finding them this year.

Here are some more pics from today:

 A trio of penguins (pretty sure they were Gentoos) rests on the edge of a large piece of ice. Occasionally you can see them move from the water to the ice which they do by “jumping”/”flying” out of the water and landing on the ice – sometimes on their feet. It's pretty impressive to see happen.
This ice chunk had icicles on its edge.
 At one point, we had the LMG head in front of us to help clear a path in the ice for us which made our travel a bit quicker. We were able to collect data while we followed them down the middle of the Bay.
The Gould was always close by, keeping an eye on us.
The other small boat was towing nets in the water to collect krill.  When the zodiac's stopped occasionally, we would see individual krill pop up and appear underneath our boats. Maybe they thought our zodiacs were oddly colored pieces of ice. Small krill like hanging out underneath ice as there is algae (krill food) that grows on the bottom of some pieces of ice, and the rough surface of the ice bottom provides them nooks and crannies to hide from predators.

- Joe

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