Science Updates!

See the data and figures before the scientists spend months thinking about it!

Results hot off the press!

Back on land we’ve been busy analyzing all our samples and writing up the results! A couple of the results papers are now published!

You can read all about where we found krill in winter, and why we think they were where they were in our latest paper: Winter distribution and size structure of Antarctic krill Euphausia superba populations in-shore along the West Antarctic Peninsula.

You can also read about some of the smallest organisms we studied and some of the surprises we found in our DNA sequence data in our paper: Unexpected prevalence of parasite 18S rDNA sequences in winter among Antarctic marine protists.

More results papers to come soon, so stay tuned!

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Setting Up Sampling and Camera Equipment

The MOCNESS is controlled from the forward dry lab when it is towed by the ship to catch krill.  A computer program talks to the net through the tow cable.  The cable provides power and a communications link to the net when it is underwater.  Alison can trigger the nets to open up at different depths.  There are also screens showing things like the ship’s speed, wind, temperature, position, cable out, tension….Ship operations require you to pay attention to a lot of different things.

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The CTD is also controlled from the dry lab.  Mike is operating the CTD while Bethany and Kerry let him know when to trigger the sample bottles.  Bottles on the CTD will capture water at different depths and bring it back to the surface.  The screen on the right shows that the CTD is at 422 meters depth and going down at 50 meters per minute.

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Ships have lots of small spaces that are often crammed with pipes and equipment.  Here is where the dock lines are kept while we are at sea.  Before we get back to the dock the lines will be taken back up to the deck so we can tie up to the pier.  There are also lots of other smaller lines for handling equipment.

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Gabby and Dave are putting the final touches on the camera system before a dive.  We added some fins to the back of the camera’s frame.  These will let us tow the camera around and use a sonar to map patches of krill that are near the bottom.  Fins with flames are always better than those without.

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The camera system is getting ready to go in the water.  The back deck of the ship is heated from below, just like radiant floor heating.  This melts the ice and keeps the deck from getting slippery.  The deck is wet most of the time.

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On a recent camera dive we had a seal visit us and swim in front of the camera for about 10 minutes.  The camera was down about 200 meters.  The seal seemed to like the lights and may have been using them to help catch fish.  We still need to identify what kind of seal it was. 200 meters is very deep for some kinds of seals.

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Research Aboard the Palmer

Bethany is dipping a small filter disc into liquid nitrogen.  The nitrogen is about -176 degrees Celsius (-270 Fahrenheit) and flash freezes the sample.  The sample is then moved to a -80 Celsius freezer (-112 Fahrenheit).  The samples need to be frozen quickly to preserve the genetic information.  The samples will be processed back at URI to better understand exactly which species of plankton are in the water.

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Kerry is making notes and keeping track of samples.  She has taken hundreds of samples on this trip.  Being organized and keeping good records is very important.

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Becky is keeping track of core samples.  Everything is labeled so it is can be sorted out later and matched to other samples.

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Each net tow sample is labeled and stored.  All of the samples will be shipped home at the end of the cruise.  Some are stored in solutions to preserve them.  Some samples are frozen and need to be shipped cold.

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Gang is filtering seawater to sort phytoplankton.  Seawater is being pulled through different sized filters.  This separates the different size plankton so we can see what sizes are the most common in the water.  Thus far we have found that there are very few large plankton and lots of small plankton.

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In our last multicore we captured this jellyfish that was likely swimming just above the bottom.   The multicore collects sediment and the water just above it in a clear plastic tube.  You can see the top of the sediment in this picture.  This jellyfish was later set free.

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This is the ship’s forward dry stores.  Things like cereal, crackers and flour are kept here, just like a giant pantry.

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This is the walk in refrigerator.  The ship can hold food for 70 people for 65 days.  We’ve been out here for about 3 weeks, and are now starting to run out of fresh vegetables.

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This is the walk in freezer.  Meats and frozen items are kept here.  Since the ship does not go back to the United States the food is from local ports.  A lot of the boxes from Chile are labeled in Spanish.

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The galley is kept spotless.  Bill is one of three cooks on board.  It is often said that the cooks are the busiest people on the ship.  Three people cook four full meals a day for more than 50 people.  They also do the dishes, clean the galley and keep the self serve pantry stocked.

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Here is  a close up of a krill in a tank.  You can see how it moves in a swimming motion.

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Live camera captures krill and seafloor

This is a photomosaic of the seafloor taken in about 500 meters of water. The complete image is made by combining many smaller overlapping photos. Underwater you can’t take a single large image. You can see the corners of the original images. Chris’s student Dave made this image. Dave is working on this type of image processing for his masters degree.

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This is a single image of the seafloor. We have been looking at the bottom to see if there are krill on the bottom.

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This is typical image showing a few krill swimming in front of the camera system.

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This is a krill swarm close to the bottom.

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This image shows a swarm of krill very close to the bottom. You can see the bottom in the background of the image and a lot of krill in a tight swarm on the right side. We are not sure what the krill are doing on the bottom.

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When no signal is a good signal

A sample of our krill catch.  Krill krill everywhere...but what are they eating?

A sample of our krill catch. Krill krill everywhere…but what are they eating?

A basic question of our project is how krill survive in low/no food conditions. What do krill do to survive the long, dark winter in the Antarctic? Do they reduce their activity and ‘hibernate’? Do they find a food source we do not know about? So, while winter in the Antarctic may not be a very attractive time to visit, we came here to observe krill in conditions of low food, and that just happens to be in late fall and winter. Measuring plant pigments in the water is one way to measure how much plant-like food may be available to krill. When we took samples at many depths today, we found there is almost no pigment anywhere. A little bit at the surface and less than little at the bottom. A normal concentration in our home estuary of Narragansett Bay may be around 3-4 and up to 25. The concentration we are measuring here is 0.1. So, while making such a small measurement is not satisfying to the mind who wants to detect and discover, the result is telling us that we have found exactly the conditions we are looking for. Now, we are off to see what the krill do under these ‘stressful’ conditions. Are they stressed, or more likely, do they have ways to cope?

-Susanne Menden-Deuer

Our filter manifold.  Water is poured into each cup, and filtered to capture the plant pigments in the water.

Our filter manifold. Water is poured into each cup, and filtered to capture the plant pigments in the water.

Categories: Musings of an Oceanographer, Science Updates! | Leave a comment

Let the Sampling Begin!

Here in Wilhelmina Bay, it’s not all whale watching and penguin gazing. We’re out here to explore the science behind these amazing organisms–mostly, the small and abundant animals and marine algae supplying the food and energy for the “charismatic megafauna.”  We’ve been pulling out all of the stops, deploying all of our instruments into the water to sample the krill, phytoplankton, and even the sediment at the bottom of the ocean, in order to get a clear sense of the food web dynamics in this amazing ecosystem.

One of our krill experts on the ship, Meng, has estimated the abundance of krill in this single Antarctic bay to be 3.7 million tons!!!  3.7 MILLION TONS! This information is based on extensive surveys of the area that can detect the acoustic reflectance of krill swarms using ADCP, or Acoustic Doppler Current Profiler.

We know who’s eating the krill (our whale and penguin friends), but we want to know: what are all of these krill eating?!

Here’s a first glimpse at some of the ways that we’ve been sampling the environment in order to answer this question:

We use nets.  LOTS of nets!  By deploying these off of the ship, we can catch everything from krill to the phytoplankton that they feed on.  Here’s an example of one type of net that is used for sampling the Antarctic water column.

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We also use something called a MOCNESS–basically, a series of nets that allow us to sample krill at different depths.

We’ve also been sampling the sediment.  It has been suggested that, during times of the year when phytoplankton are less abundant, the krill may feed on sediment rich in nutrients. This sampling is fun…and VERY muddy!  Here’s a picture of our sediment “MEGA CORE”!

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This instrument is put over the side, and dropped to the bottom of the ocean (here, about 520 meters), where it sinks into the sediment to collect large columns of mud, bringing an intact sample to the surface.

We use a CTD (conductivity, temperature, depth) that can measure important properties of the water, and collect water samples at different depths, bringing the water to the surface for the scientists on board to analyze.

Once on board, we can use this water to conduct experiments that examine rates of algal growth, and the grazing of single-celled predators.  We use these on-deck incubators to conduct our experiments, while keeping the organisms cool.

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We’ve also been conducting some REALLY COOL filming of the krill in the water!  We’ll update more on that later.  Also, stay tuned for an update on some krill experiments in progress–these involve tethering the krill (putting them on a leash!) and filming their response to different prey items.

This is a first glimpse at some of the cool sampling that we’ve been conducting.  Stay tuned for more pictures and updates as our findings emerge.

And, don’t worry Mom, we’re always wearing our hard hats on the back deck 🙂

always wear your hard hat!

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