The activity experiments continue onboard

Kim and Malin working on the tail end of the activity experiments, after the animals come out of their “hotel rooms.”
Malin removing the copepods from the tubes to take photos of them under a microscope.
Cool! Here Malin is taking photos of the copepods that were used in the experiment, to later measure their lipid content. The outline of the lipid sacs can be seen on the computer monitor. The copepods used in this experiment are lipid-rich, meaning they can store energy inside their bodies and become a good food source for animals like fish and seabirds.

-Erin Kunisch (PhD candidate, UiT)

Life at 81 North

We are the northernmost people in the world (or we would like to think so)!

-Erin Kunisch (PhD candidate, UiT)

Snowy and dark! We are waiting for the multinet to come up from the water.
Cold enough at 81N that the snow makes nice patterns on the boat.
Live Arctic creatures! There are ice associated amphipods and a Clione limacina in this bucket.
Preparing the multinet before it goes overboard.
The nets tended to freeze in the Arctic weather, so we had to bring buckets of hot water out to melt the ice that had accumulated on them.

I like the night life, I like to boogie: night life of the ocean microcosm

Who said that the polar night is nap time? According to recent research, the polar night has a relatively high biological activity, disproving the common belief that everything goes to sleep during the full-night cycle in polar regions. If you ask my small critter, life goes on like usual even if the lights are off! You can think of them as teenagers at New Year’s Eve instead of grandparents getting ready for bed…

And I think that this is very interesting! So here I am, studying small copepods (small crustaceans at the base of the food web) during this Polar Night cruise. My aim is to gain an insight of their reproductive output during winter and relate it to the distribution of their different life stages.

The big picture is to understand how small copepods’ ecology differs from the bigger copepod species. It is believed that small copepods will adapt more easily than the bigger species to a warming Arctic. This is due to their different ways of living. Most big copepods hibernate for winter and possess a long life cycle adapted to the strong seasonality of the Arctic. It is predicted that in the future, the Arctic algal bloom (the food source of copepods) will arrive earlier in the spring and there will be a second autumnal bloom. Therefore, it could prove challenging to adapt to an earlier food supply when their life cycle is timed to a later productive season.

On the other hand, small copepods like Oithona similis and Microcalanus sp. have a more flexible biology, meaning they can live in a wide range of temperatures (they are found throughout all of the world’s ocean). They have shorter life cycles, but reproduce year round which means that their offspring can take advantage of any productive food event.

To help me I have Peter Glad, the Filtration Guru, whom I want to thank for his invaluable help during the cruise. Peter helped me filter the water at our different sampling stations. Water filtration gives an indication of the amount of food available to small copepods, both algae and detritus. The amount of food available can then be linked to their metabolism and their reproductive output.

Coralie Barth-Jensen (PhD candidate, UiT)

Coralie looking for small copepods. She needs live copepods for her experiments, so she cleverly sucks them up using a long tube attached to a glass pipette (shown in video above).
Coralie and Peter working through the filtered water samples.
Peter also helps with the crazy amount of labeling we do onboard!

 

Vafler (Waffles) on board!

Waffles have a special place in Scandinavian culture. Compared to Belgian waffles, Norwegian waffles are thinner, and often heart-shaped. Waffles are usually served later in the day with coffee, brun ost (brown cheese, it is amazing!), raspberry jam, and cream.

Everyone onboard is indebted to the chef and the steward for providing delicious meals, along with valfer and sveler breaks (delicious Norwegian pancakes served midday). Thank you! Hjertelig takk!

-Erin Kunisch (PhD candidate, UiT)

Waffle break!

 

The Helmer Hanssen crew also enjoys vafler.

 

Sampling in the Arctic during the Polar Night

The fish team has been using a MIK net to sample the pelagic (open water) zone during our cruise. A MIK net (shown in video below) has a large opening and can be towed at certain depths and is eventually brought to the surface.

Things were not so calm the day the fish team brought up this net! Around this time it was -14C with winds up to 17 km/hour. Brrr. Thanks to Malin Daase for this excellent video!

-Erin Kunisch (PhD candidate, UiT)

 

11 January: Wanted! Have you seen me?

We are now in at 81N, 14E. It took us some time getting up here, but we are finally north of Svalbard!

One of the reasons to travel this far north is to look for ice-associated amphipods. Amphipods are members of the crustacean family, and can be found in many different marine and freshwater habitats. In the Arctic, amphipods can be found in the benthos (sea floor), in the pelagic (open water) zone, as well as under and within sea ice.

Arctic sea ice has been drastically changing—it has become thinner and the overall extent of sea ice has been shrinking. While disappearing sea ice has immediate consequences for larger marine mammals that rely on sea ice for a hard surface to give birth (many species of seals) and to travel and hunt (polar bears), the smaller animals that use sea ice as habitat will also be affected.

In 2012, researchers found one ice-associated amphipod species, Apherusa glacialis, as deep as 2000 meters, far away from their sea ice home. They suggested that Apherusa might be using deep-water layers to overwinter, then migrating back up to the sea ice in the spring. This hypothesis (which you can read more about here) is compelling, as many scientists wonder how ice-associated organisms (from amphipods to polar bears) will survive without sea ice. Therefore, we are on the hunt for amphipods. We are casting deep-water multinet samples (as deep as 1800m!) to see if we can find any of these ice-associated amphipods in deep water. So far, we have found two Apherusa glacialis at 800-400m depth (one juvenile and one pregnant female).

-Erin Kunisch (PhD candidate, UiT)

Erin looking at a couple of sympagic amphipods found in one of the nets.
Bodil captured this great photo of a pregnant Apherusa glacialis (you can see the small eggs she is carrying underneath her body). Females carry this pouch until the eggs develop into tiny babies, and then release tiny Apherusa. Ice associated amphipods: the tiny kangaroos of the sea.

 

 

 

Lights in the dark

While the sun never rises above the horizon up here during polar night, it does get a little brighter in the southern sky at midday, around the hours of 10am and 2pm. Add to that some light from the moon which is getting fuller every day, a little light from the stars, and a dash of aurora (northern lights), and there are quite a few photons here. In all, this makes for an interesting mix of skylight that still appears pretty dim to the human eye, but can be measured with instruments we have brought along. So each day at noon, Kim Last and I dress up in our warmest clothing and measure these photons in the sky. We have made a great set of measurements so far, starting as we left the dock in Tromsø, and continuing through today here in Krossfjorden. A big theme of the Arctic ABC project is light, and these measurements will be useful for interpreting the data generated by ice-tethered POPEs to be deployed in the near future.

But there is another bit to all of this. Many zooplankton swimming around in the waters up here produce their own light – they are bioluminescent. We have also brought along instruments to measure bioluminescence in the ocean. After Kim and I measure light from the sky, I run down to the CTD garage and lower these instruments, which we call the “light cage”. It takes about 30 minutes for the cage to descend to around 100 meters, stopping at intervals along the way to slurp up luminescent animals and record the light that they emit. Once the cage is back on the ship, I recover the data and after the cruise will examine how much bioluminescence exits at our stations, and determine the identity of the organisms doing it, which can be done by looking at the speed that the flashes of light occur.

In all, measuring light in both the sky and underwater is providing us with information on quantities of light that are not obvious to the human eye, but are important parts of marine ecology in the polar night.

-Jon Cohen (Assistant Professor, University of Delaware)

Jon with the light cage.
Programming the finishing touches to the light cage before it goes into the water.

 

All about clocks

It’s very rare indeed that you can immerse yourself in science, 24 hours a day, for days on end. But that’s exactly what’s going on aboard the HH (R/V Helmer Hanssen). We sleep (a little), eat (really great food) and work, (“crunch” data) and discuss science (when not sleeping, eating or crunching data). It’s terrific, and a privilege to be part of this cruise!

I’m interested in zooplankton behaviour and how they respond to light, or more specifically lack of it. You see, most of the planet experiences very regular light/days cycles with virtually all biological processes “entrained” to this cycle. Underpinning this is the circadian clock, a molecular machine which allows animals and plants to anticipate future cyclic events, much like you or I when we wake in the morning just before the alarm clock goes off – it’s our circadian clock, not the alarm telling us when to rise! In order to study this process we need a special device that measures cyclic behaviour, no mean feat when you are looking at a zooplankton only a few millimetres long. We use arrays of “activity monitors”, more usually found in labs working on fruit flies, which enable us to house hundreds of animals all individually swimming about in test tubes about the length of your index finger. If we see a rhythm of activity we know that this is the expression of the circadian clock and may aid survival when light is limiting. However, the activity monitors also provide data on frequency of swimming, telling us if they are hibernating or still actively looking for food. We can also tell differences between male and female swimming, useful for example, in understanding mating behaviour. Ultimately, since zooplankton are at the base of the food chain, supporting fish stocks and sea mammals, deciphering how they function and survive during the Polar Night is central to what we aim to achieve. However such science requires a lot of teamwork and without the researchers aboard the HH to help, and for inspirational discussions leading to new experiments, none of this would be possible.

Now it’s time to sign off and check on the animals, download the latest activity data. It’s a bit like being a detective I imagine, the data will hold clues and lead to the next experiment. I suspect it might be a long night.

-Kim Last (Professor, SAMS)

Kim’s activity hotel–it was a busy place during the cruise, at capacity almost every single night!
Kim working on the vials that will store individual animals (like copepods).
The “rooms” of the activity hotel.
To recreate a natural environment, no white light was used during the experiments.

9 January: Ever changing plans-an unexpected day in Krossfjorden

Now that we have safely transferred the Arctic ABC technology team to the Marine Laboratory in Ny Ålesund with all their equipment, our plan was to first to head west towards the shelf break for one deep station in the core Atlantic water inflow; then we wanted to head north towards Rijpfjorden and the shelf-break north of Svalbard. Well, again weather changed our plans and, again, we have to adapt our sampling program. The wind had picked up after we had last checked the weather forecast in the marine lab in Ny Ålesund and a storm warning was now, again, on the horizon. Besides the difficulty of operating our gear in strong winds (and people’s stomachs feeling unhappy) the team on the bridge is very concerned about icing of the vessel. With the winds coming from the northwest and high waves hitting the boat and coming over the bow, the vessel would be covered in a solid and heavy ice layer, adding a lot of undesired weight. The only option at the moment is to stay in the fjord.

While this is rather (very) frustrating, all 14 of the science crew still onboard quickly agreed that no valuable ship time should be wasted by just sitting and waiting for better conditions. The observant cook must have noticed our disappointment and handed out a round of ice cream as we sit around the couch table in the lounge next to the mess and discuss our options. With that treat and the sense of an unexpected opportunity it takes no longer than some minutes before the group comes up with all kinds of new plans! Coralie sets up a new 3-station transect stretching across Krossfjorden (just north of Kongsfjorden where Ny Ålesund is located), Kim and Jon design an additional experiment to study individual copepod behaviour of a different species than before, Martí moves his planned experiment to this fjord, the trawl team hopes for more polar cod that are in good enough shape for sampling and so on. Soon we are underway to the innermost part of the fjord in the vicinity of the glacier front. And actually the moon is lighting up just enough of the winter wonderland fjord scenery to get a sense of place. In the protected fjord waters, sampling progresses according to Plan B (well, perhaps Plan M by now). We do keep up our hopes for better weather to allow offshore sampling!

-Bodil Bluhm (Professor, UiT – The Arctic University of Norway)

On our polar night cruise, Bodil is serving as cruise leader. It keeps her busy and sometimes she has to jump out of her boots to run upstairs!