Picture of the Day - November 9, 2011

After two days of storms, our return passage through Gerlache Strait is lit by sunshine reflecting off the ocean and surrounding peaks. A sparkling blue-and-white morning! 

Photo and text by Ann Bucklin

COLLECTING LIVING PLANKTON FOR EXPERIMENTAL STUDIES

Collecting planktonic animals alive and in excellent condition for experimental work is difficult using conventional nets. Often the delicate animals are damaged when they enter the net and brush against the sides of the netting or when they are crowded and crushed, this usually occurs with small cod-end buckets and during tows longer than 40min. On this cruise, it is very important that we collect the salp, Salpa thompsoni in as pristine condition as possible because individuals will be put into an aquarium on the ship to study how being in different food regimes and temperatures affects the key genes that control physiological and biochemical processes.   “Blue water” diving in the upper 20 to 30 m of the water column from a zodiac away from the ship is one technique used to capture animals without damage, but that option is not available to us. Instead for sampling animals alive, we brought along a simple net system that was devised years ago to capture animals in very good condition. In 1981, Dr Michael Reeve took a conventional ring net and equipped it with a large weighted cod-end. He then lowered the net to a particular depth and then hauled it vertically very slowly back to the surface (5 to 10 m/min).  The animals collected in this manner were usually in very good condition.

While steaming down the Gerlasche Straits during the afternoon of Nov. 7th, we assembled a Reeve Net for use on this cruise. First we undid the lashing holding an old 1-m ring on a 1-m diameter pipe ring.  New nylon line was provided by Kelly Watson, a Marine Technician (MT) on our cruise. This line was used to lash a new Reeve net with 505 um mesh onto the ring. The Dacron collar at top of the net has a series of brass grommets through which the line was drawn and then lock-stitched (see Fig. 1), thus attaching the net to the ring.

Fig. 1. Paola attaching the Reeve net to the ring with nylon line.

The net is 4.1 m (13 ft) long. After getting the net attached to the ring, we assembled the cod-end bucket, which is a large PVC bucket [0.46 m (18") tall; 0.32 m (12.75") in diameter]. The cod end was inserted into a support bag made of mesh netting. The bag was then attached to the back of the net with a heavy-duty zipper.  Then the top of the bucket was taped with black electrical tape and duck tape to prevent chafing. A piece of Tygon tubing with a hose clamp inside was placed just under a lip of PVC to seal the mesh bag and prevent animals from passing down the outside of the bucket and out through the coarse mesh. 

Four ½" nylon lines run from the top of the pipe ring to the cod-end (Fig. 2). These were adjusted in length so that - when attached by shackles to straps on the mesh bag - they were loose and not supporting the bucket. The lines are intended to be used in retrieving the bucket after a tow; during a tow the net supports the bucket.

Fig. 2. Paola standing next to the Reeve Net hanging in the Baltic Room on the LM Gould. She is holding one of the lines used to haul in the cod-end bucket. Photo by P.H. Wiebe

Finally, we made a bridle from which the net will be towed.  Using Stainless steel thimbles also supplied by the MT shop, the remainder of the nylon line was used to fashion a towing bridle. 

Additional sampling gear such as the Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS) and the Isaacs-Kidd Midwater Trawl (IKMT) will be used on this cruise. After looking at samples collected by these gears, we can determine whether we have encountered a patch of higher salp abundance or not. The MOCNESS will also provide information about the depth at which the salps reside. Once we have this information, we can use the Reeve net to target the areas and depths where we can collect salps in good condition for the shipboard experiments.

-- Paola Batta-Lona (University of Connecticut) and Peter Wiebe (Woods Hole Oceanographic Institution)

Picture of the Day - November 8, 2011

Arrival of the LM GOULD at Palmer Station, Antarctica, on November 7, 2011

Photo by P.H. Wiebe

Spanning the Latitudes - The Canadian's turn to Blog

Last year at the end of October, I was returning from 32 days in the Canadian Arctic as a participant in the Joint Ocean Ice Study (JOIS), a collaboration between Canada, the USA and Japan. This project set out to study the Beaufort Sea and its ice coverage as well as look at the variability in the Beaufort Gyre. We collected water for multiple analyses (oxygen, salinity, nutrients, dissolved inorganic carbon (DIC) to name a few), took plankton samples, deployed both floating and ice-situated moorings and took ice thickness measurements from the ship. All the while being amazed by the Aurora Borealis, Polar Bears and sunsets over an ice-covered vista,

On the ice in front of the Canadian Coast Guard Ship, Louis St. Laurent  (Photo by Jeffrey Charters)

Skip ahead a year and I am preparing to head to the other end of the world. This time 30 days in the Antarctic, as the token Canadian aboard the Laurence M Gould. As an Acoustic Research Technician for the Department of Fisheries and Oceans Canada, my interests lie in the fields of fishery and plankton acoustics. What this basically means is looking at fish and plankton in the water using a big, fancy, scientific fish-finder. When the opportunity to apply to participate in the 2011 Antarctic Salp cruise was presented to me, I jumped at the chance. Not only would I get to see Antarctica, but acoustics were going to be a major part of this cruise. For the next few weeks, I plan to annoy...I mean learn from the researchers on this cruise as they utilize acoustics and different methods of plankton sampling to answer the questions posed on this survey. Needless to say, I am very excited to be here! The learning should start soon, as we spend today at Palmer Station unloading supplies for the station, hoping to head out and start our Salp survey tomorrow. Wish us luck in the form of ice-free waterways and little to no wind!

Happy to be at Palmer Station (Photo by Melissa Mazzocco)

-- Chelsea Stanley, Department of Fisheries and Oceans Canada (Sidney, BC)

WEATHERED OUT AT CAPE SHERRIFF, LIVINGSTON ISLAND

Just before 12:00 Noon on Nov. 5th, we arrived as planned at Cape Shirreff. The weather is iffy, with winds blowing 30 kts out of the N-NW; air temperature at 2.7 degrees C; and the barometer reading 993 mb.  After waiting a bit for our best weather window, a first attempt was made to launch a zodiac (Fig. 1), intended for a scout team that would survey the area and check out the research station. A few minutes after the launch, it was clear that conditions were too rough to go any further, and the zodiac was brought back aboard. We held position off Cape Sherriff for the afternoon and through the night, hoping for workable conditions for small boat operations needed to transfer people and gear to open the NOAA Marine Mammal Research Station for the summer season.

Figure 1. Launching a zodiac in rough weather takes excellent coordination of the ship’s crew and technical support team.

The next morning (Sunday, Nov. 6th), winds blew at 15 - 20 kts out of the NE, with choppy seas and a few white caps. A check of the conditions indicated: air temperature = -0.1 degrees C; sea surface temperature (SST) = -0.9 degrees C; and salinity = 33.9 PSU. The barometer reading (986 mb) was far lower than the past few days, indicating a low pressure area and indicating bad weather might be coming our way – and so it was!

By mid-morning, low fog moved in, reducing visibility from the ship and obscuring the land – not safe conditions for small boat operations. By early afternoon, it was snowing and the wind picked up to around 20 kts. Air temperature was 0.5 degrees C; the barometer reading (978 mb) indicated that the low pressure system to the west had moved in ahead of schedule. A panoramic view of Cape Sherriff (Fig. 2) shows the conditions and lay of the land clearly – so near and yet so far away!

Figure 2. Panoramic view of Cape Shirreff from open sea to the east to open sea to the west (left to right in image) assembled from 12 images merged using Adobe Photoshop.

The winds really picked up during the afternoon, blowing 30 - 35 kts. Low clouds moved in and the barometer was at 976 mb and falling. By 5:00 PM, winds were gusting out of the West to 55 kt (Figure 3).  The only good news was that the barometer was starting to move back up!  The wind and weather forecast for tomorrow indicated high winds would continue through the day. 

Figure 3. The ship’s Data Acquisition System (DAS) screen showing wind speeds and gusts up to 50 kts during Nov. 6th.

The Captain (Joseph Abshire), Marine Projects Coordinator (Jullie Jackson), Chief Scientist (me), and lead scientists (Joe Warren and Peter Wiebe) met to discuss options and priorities to work toward the cruise scientific objectives despite the bad weather.  After listening to our recommendations and considering the many competing needs and objectives of the cruise, the Captain decided to steam away from Cape Shirreff and head for our Station 22.  We hope the protected location of the station at the entrance to Gerlache Strait will allow us to occupy our first station, carrying out planned sampling and data collection. Our ETA (Estimated Time of Arrival) for Stn 22 is 5:00 AM on Monday, Nov. 7th.  We left our requests for wake-up calls with the bridge, and headed to our bunks for a short night.

Upon our arrival at Stn 22 in the early morning of Nov. 7th, it was clear that we didn’t have the protection from wind and weather we wanted to carry out our first “training station” of the cruise. Winds were still in the 30+ kt range, with gusts to 50 kts. After some discussion with the Captain and MPC on the bridge, the decision was made to head directly for Palmer Station.  We hope to be able to tie up to the dock by this evening, off-load people and cargo tomorrow, and head back to sea tomorrow evening.

-- Ann Bucklin, University of Connecticut

Picture of the Day - November 7, 2011

Photos by P.H. Wiebe

Picture of the Day - November 6, 2011

The NOAA Marine Mammal Research Station at Cape Sherriff, Livingston Island.

A team of US scientists led by Mike Goebel (Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, La Jolla, CA) and team members Kevin Pietrzak, McKenzie Mudge, Nicole (Ashley) Cook, and Jay Wright will spend up to 3 and 1/2 months here. The resulting long-term observations of Adelie, Gentoo, and chinstrap penguins, fur seals, leopard seals, and other birds and mammals are leading to new understanding of how polar and sub-polar species may respond to climate change. Although everyone is eager to transport the scientists and their gear to shore and allow them to open their summer camp, we are waiting for safe weather conditions in which to operate the small boats.

(Photo by P.H. Wiebe)