Thursday, November 10, 2011

10 Nov – On Station !

Yesterday afternoon, we had our first science station of the trip. We left Palmer Station in the early morning and were transiting back to Cape Shirreff to deploy the field team there, but on the way was one of our stations (#22 to be specific). Given that some of the gear we were using on this trip hasn't been deployed by members of the crew or the science team previously, we decided to do our first station here (at the northern end of the Gerlache Strait) in semi-protected waters which would help for our deployments to go smoothly. 

Traveling through the Gerlache strait, we encounter many types of ice. In the background are the cliffs of a glacier (probably 80-100 feet high), with several large bergs in the foreground. The nearest piece of ice has dark lines/regions which are most likely rocks and dirt from the continent (or islands) around here, meaning this piece of ice used to be on land and as it moved slowly across the land, the ground beneath it gets incorportated (somewhat folded into) the ice itself
On the way to Station #22, we passed through some really spectacular scenery with mountains, glaciers, icebergs, bergy bits, growlers, brash ice [those names all mean something different with respect to the size or type of ice we see] and we even had some sunshine along the way. There was also a group of penguins porpoising (swimming near the surface and occasionally jumping out of the water – so they can fly!  Just very very very short distances.). 

If you look very carefully in front of the piece of ice in the photo, you can see a group of penguins (maybe 12-15 animals) travelling from left to right. Penguins often travel by porpoising (swimming near the surface and sometimes “flying” out of the water). These were pretty far away so it's difficult to tell what species they are, however these animals have orange feet and a black head with a white patch above their eye which makes them Gentoo penguins.
We made it to our station around 3pm in the afternoon and began to do our science. We have a set of standard instruments that we deploy at all stations: a CTD rosette and two types of nets, a MOCNESS and an IKMT. The CTD is an instrument that measures water properties as well as bottles that collect water samples for us to analyze on board the ship, it's lowered from the surface of the ocean to 1000 m depth (or the bottom – whichever comes first). From these data we can tell a lot of information about the physics and biology of the area.

The IKMT net is used to collect live organisms for us to do measurements on back on the ship.  It's towed for a short time period as the zooplankton tend to get damaged by longer tows through the water column.  The other net is a MOCNESS system and we happen to have its inventor (Dr. Peter Wiebe, from the Woods Hole Oceanographic Institution and, full disclosure, one of my Ph.D. Advisors) onboard with us as part of Dr. Bucklin's science team. We'll have a blog post dedicated to the MOCNESS system as it's a really remarkable piece of equipment that not only collects animals, but also measures environmental information about the water where the animals were living.

All three of our systems were deployed (and recovered !) successfully. Although there were some hiccups.  Right before we deployed the IKMT net, we noticed that there were two small tears in the mesh. That happens somewhat frequently given that the ship and net frame and various other things are sharp onboard the ship and the mesh (which has holes in it that are about a half a millimeter in it) is somewhat fragile.  If you send down a net with rips in it, there are two major problems: 1) you might not get a representative tow since animals might be escaping through the holes and  even more importantly 2) the small tears might become larger tears which could ruin the net. Marine Technician Kelley Watson and I spotted the two rips, so we got out the net repair kit which means the tow of us got to “patch” the nets with our sewing techniques. Luckily, Kelley (like all sailors) has excellent sail-making and repairing skills in addition to seamstress skills and I've had to repair nets several times in my scientific career.  We got the holes patched up and deployed the net. 

 MT Kelley Watson (left) and myself (right) break out the needle and thread on the deck of the LMG to repair some small holes in the net before we deploy the IKMT. Fortunately, the seas were pretty calm during this repair, although it did start snowing during the MOCNESS deployment. Photo by Peter Wiebe.

We caught some interesting stuff in our nets tows, but I'm not sure anybody took any pictures last night as we were processing the samples (starting some experiments in our cold van, preserving zooplankton in jars which will be counted and analyzed back on shore after the cruise). But don't worry, we'll have get you some pics soon!

-Joe

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