In the fog, we were steaming to our next station in the morning.  We are in the southern part of our cruise again so we are out of the ice, but we are heading north so we should be back in the ice shortly.  One of the first orders of the day was to collect the sediment traps that had been deployed yesterday.  The scientists deploy the sampling device for 24 hours at which time it floats along in the currents until it is retrieved the following day.  (More to come on this.)  The seas cooperated and were very calm for a successful retrieval.  

A little while later, I received a page from the bridge telling me that there was an owl flying around the bridge.  AN OWL?  I went up to the bridge and I had missed the owl.  I was reassured that he would come back because owls don’t belong in the Bering Sea and he would want to come back to the shelter of the ship.  A few minutes later, he flew back into view and we had a great look at him.  He looked very tired so we hoped that he would land on the ship to rest.  Indeed he did, landing first on a small railing, then on the A-frame, and finally on the bow where he hung out for a while.  The bird researchers determined that it was a short-eared owl.  This little guy was far from home but it was very cool to see him.  Definitely the highlight of the day.

  

 

Out in the cold and dark early morning the zooplankton ecologists wait for a net tow to come up from the depths in order to collect krill and copepods for their experiments.  Once the net comes up, they put the “bugs” into coolers and get ready to go into the cold room to sort them.  The cooler is teeming with krill, copepods, Clione (a type of pteropod), amphipods and other varieties of critters.  I follow them into the cold room where they divide the plankton and begin sorting through to get the dominant species to run their grazing and other experiments.  Dr. Carin Ashjian from the Woods Hole Oceanographic Institution and Dr. Bob Campbell from the University of Rhode Island, with the help of Phil Alatalo and Donna Van Keuren, lead the team which is conducting experiments about the grazing impacts of the mesozooplankton and the fecundity of the animals.  

“Deploying the ring net used to collect the copepods and krill needed for the team’s experiments”

 

Their first set of experiments focuses on the grazing of the dominant species of the mesozooplankton, particularly copepods and krill.  The mesozooplankton plays a key role in nutrient cycling in the ocean as they provide a key link between the primary producers (phytoplankton) and the larger animals.  Their waste settles to the sea floor providing key nutrients for the benthic system.  They sort the animals and place individual species into jars with seawater collected from the depth where the animals live.  The water is tested for the beginning concentration of chlorophyll which indicates how much food is in the water at the beginning of the experiment. Most mesozooplankton are omnivorous but the team uses chlorophyll to estimate how much of the plant biomass is eaten and to determine the proportion of primary production consumed by mesozooplankton.  The jars are then placed in various wraps to emulate the light conditions they would have at depth and they are placed in an incubator of ambient seawater for 24 hours where they rotate and mix constantly.  After this period, the jars are brought to the cold room which is kept at -1 to -1.5 degrees Celsius, where the animals are removed and put into dishes and the water is divided into various bottles for analysis.  The water will then be tested for chlorophyll concentration to quantify the changes to biomass.  The animals are then dried and packed away to be analyzed for carbon content once back on land along with samples of microzooplankton, phytoplankton and ice algae to determine the food preferences of the bugs.  In this way, Dr. Ashjian, Dr. Campbell, et al are able to quantify the role the mesozooplankton plays in the trophic structure (food web).  

“Phil Alatalo sorts through the sample for animals to use in the experiments”

 

“Copepods”

“Krill”

“On the bow, the incubators hold the samples for 24 hours in ambient sea water with constant agitation”

 

Their second experiment is looking at fecundity in females, counting the number of females with eggs, counting eggs and measuring rates of hatching.  The females are collected and put into the  “bug hotel” which I am told has a total occupancy of 120 copepods and is located in the cold room where they check in for 24 hours at which time their eggs are counted and a sub-sample is taken for the hatching studies.  These studies seeks to determine the timing and magnitude of reproduction in relation to what the copepods are eating, is it a function of lipid (fat) reserves, the presence of ice algae or other algal species?  These studies can then give the scientists an index of individual growth and food limitations on this growth.  

“Dr. Campbell carefully picks female copepods out of a sample to put into the bug hotel for their egg studies”

 

“Dr. Campbell puts a tray of female copepods into the bug hotel for the egg growth experiment”

 

The copepod team provides key information to the understanding of a key element of the ecosystem.  By sampling in different areas from north to south in the Bering Sea and at various depths and ice coverage, the team is analyzing the effects of the seasonal ice and what could happen if it is not here. Where will the carbon go if the sea warms and there is less ice, to the mesozooplankton or to the benthos (sea floor)?  

 

“Dr.Ashjian and Dr. Campbell remove the animals from the experiment jars in order to preserve them for analysis of carbon in the lab. The water is siphoned out for chlorophyll concentration studies.”

 

Today has been a slower day.  The sun is shining and the sea is calm.  It was a beautiful morning with temperatures around freezing here in the open water.  We are heading towards the shelf edge to do some benthic sampling before heading back to our process station to assess any changes on our quest to find productivity and a possible phytoplankton bloom near the ice edge.  It is a relatively quiet day on the ship with some samples being processed and others collected.  Birds were hanging around the ship as we were on station with the multi-core in the water.  We are in 500m of water so the sampling took a fair amount of time.  

I took this opportunity to sit outside and look out at the Bering Sea and think about how beautiful and calm it is out here today and how quickly the weather out here can change.  However, the weather maps indicate that a high pressure system is coming through so hopefully that means nice weather for the next few days.

As the day continued, the clouds took over the sunny sky and the sky became dreary.  The seas remained calm.  We are doing a zigzag pattern for our stations now and came into a productive area in deeper water.  

I stayed up to see the net tows which happened around 1am.  I was anxious to see what kind of critters were in the water.  There were three net tows at this station and sure enough, there were lots critters in the water: copepods, krill, pteropods, polychaete worms and some little fish, among other critters too small to identify.  The water is mostly filled with copepods which are small crustaceans.  We are now headed north to our next station and tomorrow I will find out where we are going next.  We should be back in the ice by Sunday so I am looking forward to that! 

“The Fan Tail”

 

“The krill sampling team and the marine science technicians bring in the bongo nets in the darkness” 

 

“A bucket teeming with copepods, krill and other plankton. Without a microscope, it looks like thick red/orange soup.

 

 

 

 

Yesterday, I had a chance to sit down with the chief scientist, Dr. Carin Ashjian, a zooplankton ecologist from the Woods Hole Oceanographic Institution, to find out more about the mission of the cruise, her role as chief scientist of the expedition and her research.  

The mission of the cruise is to determine the importance of the ice and the seasonal melt on the ecosystem in order to determine how different ice conditions affect it.  Essentially, the scientists want to know how important the ice is and what would be the impact if the ice disappeared in the future.  On this cruise, the researchers are looking mostly at the base of the food chain, the phytoplankton, zooplankton, sea floor gas exchange and animals and some physical oceanography to put it all into context.  

With twelve projects going on and forty-six scientists on board, there is a lot to manage and Dr. Ashjian must make sure that everyone gets the samples they need to complete their projects.  This is quite a challenge!  Many of the projects are time dependent or location specific so a careful plan is key.  Unlike in the laboratory, variables change at sea, so while a cruise plan may seem perfect while on land in the planning stages, sea conditions, weather and in the Bering Sea, the ice, may force the original plan to be changed.  Improvisation and flexibility is the key but any changes must be made within the parameters of the project.  For example, one team is studying krill and their samples must be collected at night.  For this reason, we must be at the sampling location around 3am or the work cannot be completed in the dark.  (The sun has been setting at 11:30pm and the days are getting longer and longer.)  Much of the work is collaborative so the samples must be taken at the same location.  For this reason, most of the sampling is completed in the middle of the night.  Dr. Ashjian is responsible for discussing the cruise plan with the Captain, officers and crew and making sure that everything runs smoothly.  

In addition to the multitude of responsibilities associated with being chief scientist, Dr. Ashjian is conducting her own research on copepods and other dominant mesozooplankton (highlights coming soon).  She adds that this is one of the most challenging jobs she has had.  Thus far, all of the scientists are learning a great deal and collecting samples to analyze when back in the lab.  

Our next course of action is to look for areas of high production near the ice edge and continue sampling before heading north to do a specific transect in the ice on Sunday. 

 

 

 

I started the day photographing some net tows in anticipation of learning about the mesozooplankton (copepods, krill, etc) grazing experiments being conducted by a team of scientists on the ship.  I stayed out on deck for quite a while to observe, as various plankton was being collected along with some bottom grabs of mud.  It was quite chilly at about 25 degrees Fahrenheit with a stiff breeze.  The swells were sizable but not too bad.  The water temperature was hovering around -1.7 degrees Celsius, just above the freezing point, which is lower than the freezing point of freshwater.  

Shortly after we headed back north and were in the ice!  I was sitting at my desk and started hearing the crunch of the hull breaking through the ice at which point I looked at the images available from the bridge and saw that indeed we were surrounded by large islands of ice intermixed with slush.  It looked beautiful and endless so I headed outside to see it for myself.  (My desk area is in a lab without any portholes so it is easy to lose track of what is going on around me.)  The sun had come out and it was shining on the endless white undulating sea.  I headed up to the bridge to get a better vantage point at which time someone spotted some seals on a ice patch.  They were in the distance but it was still nice to see a seal or two.  Hopefully it is only the beginning of the beautiful things that are to come.  We remained in the ice for a little while and then just after dinner we were back in open water.  There is something amazing about crossing the ice edge.  The swells roll in seeming to go under the ice and the wake of the ship pushes the ice aside with ease.  

Now it is about 10:00 pm and it is still sunny with some clouds.  The sun sets at 11:30pm so I am hoping to see a beautiful Bering Sea sunset.  It has been cloudy every other evening that I have been out here so I am anxious to see a setting sun.