Benthic Studies – Boxcores, Brittlestars and Being Called Dirty
Heike Link, University of Quebec at Rimouski

It’s Saturday night, 8 pm – and my face is feeling hot from a nice sunbath on the helicopter deck. Tonight the galley had prepared a BBQ for the crew – and as the weather is spoiling us with sunshine and no winds on this day, it has definitely been one of the very special ones, that make me appreciate how lucky I am to be working in the Arctic.
I have just started my PhD in oceanography at the University of Quebec at Rimouski this March. I am working on benthic ecology, i.e. all the living things we find on the seafloor that are bigger than 0.5 mm, and about what role they play in the Arctic Ocean ecosystem.
Lots of discussions are dealing with the influence of climate change and the reducing ice cover on the Arctic Ocean, particularly on its primary production (algal blooms), and the associated zooplankton. Unfortunately, a lot of people tend to overlook the role of the benthic part in ecosystems:
Many of the animals living all the way down on the bottom of the Arctic Ocean feed on dead algae and phytoplankton, which sink down from the water column. As the animals down there consume food, they will also produce nutrients, which will diffuse back to the water column and be a part of the source for the next plankton bloom. And as the equilibrium between zooplankton and phytoplankton will change with the environmental changes, there will also be less food available for the benthos – which in turn will influence the amount of nutrients produced at the seafloor.
To understand the relationship between primary production and benthic activity, our team is measuring the consumption of oxygen and the changes of nutrients by benthic communities before and after an algal bloom.
We use a box corer to bring up a 50 x 50 x 50 cm chunk of sediment from a depth of 200 m or more underneath us. Then we incubate sediment cores of 10 cm in diameter for about 2 days to measure the oxygen and nutrient changes in the water column covering them (Fig. 1).

Fig. 1: Left - The box corer with a successful sample. Right - The incubation core setup (Photos: Haakon Hop).
To gain a better knowledge on how much and which kind life is flourishing on a dark and cold place as the Arctic seafloor, we also use an Agassiz trawl (a net dragged on the sediment). And I promise, you would be as fascinated as I am every time, to see how many crazy and beautiful animals we catch down there (Fig. 2).

Fig. 2: Catches from the Agassiz sled. Upper left – brittlestars (Photo: Haakon Hop). Upper middle – Mylène and a full Agassiz net (Photo: Lucy Calderon Pinera). Upper right – an Ampharetid polychaet worm (Photo: Mylène Bourque). Lower left: starfish Ctenodiscus crispatus (Photo: Mylène Bourque). Lower right: the Agassiz sled and the crab Hyas coarctatus (Photo: Myriam Paquet-Gauthier).
Sadly, we tend to have a dirty reputation – not for observing the little creatures, but rather for all the sediments, that we have to clean off the ship once we’re done. But at the same time, the nice brittlestars we catch seem to be too interesting for our spectators, than to be scared away by the muddy boxcore.
Want to know more? Check out Mylène’s dispatch from leg 3!

My name is Cyril Aubry. I am a research assistant of Prof. Huixiang Xie from the University of Québec at Rimouski. We are working on marine photochemistry, and more precisely on carbon monoxide, CO, in relation to the biogeochemical carbon cycle. Carbon monoxide is produced from the degradation of organic matter contained in seawater and ice.

The measurements we take provide us with a proxy for the remineralization of DOC (dissolved organic carbon) into DIC (dissolved inorganic carbon), mainly carbonates, which is hard to directly estimate as there is a high background in the marine system.
The Arctic Ocean receives the largest amount of organic carbon from terrestrial freshwater input than any other ocean. There is also an in-situ production of organic carbon from primary production, which was considerably underestimated a few years ago.
This and the lack of information on DOC loss processes in this high latitude environment are some of the reasons why we are participating in the CFL project.
This project gives us the unique opportunity to sample seawater as well as ice, and to do onboard analysis to determine CO concentrations in these samples.

Together with this exciting work opportunity, the life on the Amundsen ice breaker is a great experience. One of my most delicious ‘Carbon monoxide samplings’ was the day we had hot-dogs grilled on the barbecue at 75º North latitude, prepared by our incredible crew. That was the best way to end a day of science in the arctic…

A Few Weeks with the MVP

By Charles Brouard and Sarah Dyck

Now that the ice has started to break up the CCGS Amundsen has become an open water vessel and we can start taking advantage of the MVP. During our months of winter hibernation, the MVP is stored away, and the rosette is used via the moonpool every time we need to take a vertical profile of the water column. MVP stands for moving vessel profiler. It is a hydrodynamic CTD attached by a kevlar electro-mechanical cable to a really fast winch at the aft of the ship. Rather than stop the ship at a station and lower the heavy rosette and its CTD on a relatively slow winch, we can lower the MVP and take the measurements we need quickly while the ship is in motion. Another advantage of the MVP is the fact that, in theory, its operation is totally automated: the fish goes down to a predetermined depth off of the bottom (automatically determined by sonar), winds up automatically, waits for a specified amount of time, then descends again to take another profile a few nautical miles farther along the ship track. All of this happens while we are enjoying ourselves at the crew bar or sleeping!!!! Just joking! In reality, this complicated system needs constant supervision. During transects we need to constantly monitor MVP behavior to avoid problems as we watch for steep slopes in the bathymetry

(Fig. 1 Charles attending the MVP. Photo by Eva Alou Font).

Another crewman needs to be “on watch” at the aft of the ship, near the winch to intervene at a moments notice to take manual control in case of an emergency (the MVP is a really expensive piece of equipment and nobody wants to take the risk of losing it at the bottom of the sea , not that it ever happens of course....).

Now let's talk about the numbers! The MVP is a really fast profiler, analyzing samples of water 25 times a second. The winch itself is so fast that the fish is going to the bottom virtually in freefall (which means that the winch is supplying about 7 meters of cable per second!!!) The maximum speed that the winch is able to wind is about 3 meters per second, but we usually use a slower speed to lessen stress on the cable and avoid problems. The spool of cable is 1700 meters long, which allows us to take profiles as deep as 300 meters while moving at the speed of 12 knots. As the Admundsen Gulf is at most about 600 meters deep, and as we strive for a good safety margin, we usually need to limit our profiling speed to 5 to 8 knots, taking a profile every few nautical miles.

We now need to talk about the Fish!

The fish is what is attached to the business end of the cable. It is so named because it quite frankly looks like a fish (two eyes, an open mouth and a tail)!!! During ascent and descent, water travels through the open mouth of the fish, to the “guts”, where the instrumentation is located. The instrumentation measures conductivity, temperature and pressure which are used to calculate the density of sea water in the water column. Some sensors also allow us to measure fluorescence and transmissivity, which are parameters important to many biologists, physicists and chemists alike.

During the last three weeks the MVP has been used to profile McLure Strait, a northern passageway that has rarely been studied, either scientifically or otherwise due to ice cover. We have also completed a transect from the MacKenzie River across the Amundsen Gulf. When we began the transect from Cape Bathurst we ran into serious sea ice conditions, providing many obstacles during transit and limiting the usefulness of the MVP. We were therefore forced to use the fish as a stationary CTD when the ice conditions permitted, stopping the ship for a few minutes every time we lowered it and taking it out of the water between each cast. That is when the MVP becomes a pain to use!!! Nonetheless, even in the icy conditions of the Canadian Arctic, the MVP is a wonderful instrument allowing us to efficiently take home an incredible amount of much needed spatially distributed physical data concerning the waters of the Amundsen Gulf and its surroundings.

Algae of the Arctic Ocean and their importance for the food web

Today was cloudy, which we were not used to , and we are heading for the eastern side of Banks Island, in the Amundsen Gulf. Since my arrival on the ship, we have traveled hundreds of nautical miles, starting at Cape Perry and going as far as Mclure Strait, north of Banks Island. The main objective for our team is to measure the primary production of the Arctic Ocean. But why is this so important?

A lot of Inuit communities are depending on the ocean either for food, health or work. Global warming might have a great impact on the Arctic ecosystem, which may alter their lifestyle and well-being. The algae, which are microorganisms, are the most important ones in the ocean. They are the beginning of the food web, which means that the bigger organisms, like copepods and other zooplankton species, are feeding on algae.

The primary production of the algae is quite important, but sometimes difficult to quantify. With the rosette (fig. 1, left & right), we are collecting water at different optical depths (light intensity at different depths) measured with a natural light profiler.

Fig. 1: The rosette with CTD (Conductivity, temperature, depth) sensors

After getting the water, we add a radioactive tracer (Carbon 14) to measure the carbon uptake rate of the algae. We incubate the algae in situ for 24 hours (fig. 2) in approximately the same environmental conditions of light and temperature. To control the light intensity, we add filters on different plexiglass tubes and we measure the light inside of them.

Fig. 2: The incubator on the foredeck of the Amundsen

Then, we go back into the lab where we filter the samples in a green environment. Why’s that? Because the algae contain different pigments able to absorb different light wavelengths. However, the green is reflected by the algae, which explains their greenish color (Fig. 3).



With the radioactive products, we have to be careful and safe and we need to wear gloves and a lab coat. When the filtration is done, we analyze our samples by counting the amount of carbon 14 in each sample to determine the production rate.

With global warming affecting mostly the polar regions, this study will help our understanding of the impacts of these climate changes on the Arctic Ocean ecosystem. After starting my masters at the University of Québec at Rimouski one year ago, I can say that I have learned and am still learning a lot about the Arctic and its fragile environment. Every person should be involved in protecting our environment, which is full of many challenges, from 100 years ago into the future.

Hello, my name is Claire Evans and I am a post doc working at the Royal Netherlands Institute for Sea Research based on the island of Texel in the Netherlands. My job is to investigate the role of viruses, the smallest of all microbes, in the marine ecosystems of both the Arctic and Antarctic. With good fortune I find myself onboard ‘Amundsen’ for two legs of the CFL study which sees me the join the ship in late April and stay until the latter part of July. During this time things changed significantly in the Amundsen Gulf with the melting and flushing of the ice revealing a more traditional watery seascape. The chemical and physical changes which occur in the water column as a result of the ice retreat stimulated the growth of phytoplankton cells, tiny unicellular plants, in the surface waters. In turn the organisms which eat the phytoplankton will increase in number in response to the development of these ‘blooms’ and the levels of bacteria will increase as they can feed on matter released by these organisms. My task here is to investigate whether viruses play a role in this microbial Arctic food web by infecting and killing the phytoplankton and bacteria. This is important because when viruses infect a cell they cause it to burst open by a process we call lysis, which releases all the chemicals and matter within that cell to the water column. This influences the biology of the sea by reducing the amount of these cells available to be eaten by larger animals. In this way viruses could decrease the amount of food available for higher organisms such as Polar Bears! Also viral lysis influences the chemistry of the oceans by causing the release of the cells contents to the seawater which can change the levels of nutrients and other important substances in the ocean. It is important to study these processes as the different environments of the Earth such as the oceans and atmosphere are all linked in terms of their chemistry and biology. If we can better understand processes such as viral lysis in the Arctic and how significant they are it allows us to fit another important piece into the jigsaw that is the mysterious workings of our blue-green planet!

Horton River Dispatch

Elizabeth Shadwick, Debbie Armstrong and Dan Nguyen

Everyday aboard the CCGS Amundsen is an adventure, but particularly so when the day begins with a helicopter flight to the mouth of the Horton River, which feeds into Franklin Bay.
For approximately one week, we’d been focussing our efforts on sampling a series of stations located near the outflow of the Horton River to Franklin Bay. Satellite imagery indicated a significant outflow of particulate matter from the river (see attached figure 1). Since both the input of freshwater and of riverine particulate matter, are of interest to many of the researchers on board, we wanted to collect surface water samples from the Horton River. A few days earlier, we tried to use the zodiac to collect river water sample, but due to poor visibility and very shallow water, we could not get close enough. This meant that the samples that we brought back to the ship had a salinity of about 10 (the salinity of Arctic Ocean water ranges from 28 to 32 at the surface, while river water, which is fresh, has a salinity of 0).

It seemed the helicopter was our only option to reach the river, and to be frank, all scientists onboard are excited at the prospect of a helicopter ride. After soliciting all those interested in river water samples for bottles and instructions for water collection, we three lucky participants gathered on the heli deck.
We were given special orange survival suits, which differ from the ones that we normally wear out on the ice in that they do not float - (apparently in case of an emergency landing on the water. You don’t want to be stuck in the aircraft because your floater suit won’t allow you to dive down and swim out the door...). Once suited up, in our one size fits all or, in this case none suits, with cameras ready, we were off. The flight was spectacular. What is left of the fast ice near land is quickly breaking up and melting, making for incredible patterns on the water as seen from above. The pilot allowed us to open one of the passenger doors during the flight so that we could get clear photos of the land below.

Figure 2: Horton River (photo by Elizabeth Shadwick)

The river was only a short flight away, and we landed on a small stretch of rocky beach just beyond the mouth of the river. It has been three weeks since we have walked on land, so it was a treat to do this and it delighted us all. We waded into the river, which also means we got ‘booters’, unintentionally bringing back some of the Horton in our rubber boots. We filled various bottles and syringes with river water, which was surprisingly already 12 oC.
After the sampling there was time for a quick photo shoot with the chopper (figure 3) – and then we were off back to the ship. The ride home was equally spectacular – the scenery up here is really something to see (figure 4).

Figure 4: Sampling site (photo by Guilliaume Carpentier) from left, PhD student Elizabeth Shadwick, a MSc student, Dan Nguyen and a lab technician, Debbie Armstrong

Figure 4: ice breakup just East of the Horton River inflow (photo by Elizabeth Shadwick).

Upon return, we did a quick hose down to rinse the mud off our suits and boots (which we emptied and left to dry), and headed down to the mess for lunch. All in a days work!