Packing up

The last day of our cruise we headed south back to Longyearbyen. It was a pretty rough ride, with seas at 8 meters and winds over 30 meters/second! But we all arrived in Longyearbyen safe and sound–back to labeling (and lots of packing up)!

-Erin Kunisch (PhD candidate, UiT)

Peter, Kim, and Jon all busy organizing and packing up.
Martí labels and says goodbye to room.
Boxes upon boxes.

Amazing time-lapse videos!

Malin Daase made two amazing time-lapse videos! The first one is of the fish crew sorting trawls. We hope you can gain a certain appreciation for identifying and sorting the different species we find in the pelagic trawls. There is something truly satisfying watching things get organized and tasks being achieved! Additionally in Kongsfjord, we caught a lot of Atlantic cod–which means we eat them (why waste good fish?) after a subsample of them are weighed and measured. You can watch how fast fish are filleted onboard–though to be fair to the student, you learn by doing!

The second video is an overview of the different nets that we used during the cruise (the MIK net and the MultiNet). We talked about these different nets and why we use them, but if you can’t remember, just take a look back at our previous posts.

Thanks to Malin for these videos, and we hope you like watching them as much as we do. Enjoy!

-Erin Kunisch (PhD candidate, UiT)

The Rijpfjorden bounty

Bucket ‘o snail fish.
Paul sorting.
The pelagic trawl in Rijpfjorden. The tiny red things are Pandalus borealis (shrimps).
Leptoclinus maculatus (Daubed shanny fish).
Bodil identifying benthic species.
Herring.
Some big amphipods! The spotted brown animals are called Stegocephalus inflatus, and the reddish animals with the interesting eyes are called Anonyx nugax.
A triceratops-looking shrimp.
Actually it belongs to the Genus Spirontocaris .
Identified shrimps!
Looking at shrimps up close is a fun ship activity.

-Erin Kunisch (PhD candidate, UiT)

What the fish crew was up to–post 2

January 11th, 2017, “Max transect”, we finally made it up “north”. This year, the fish team also worked with a project conducted by Post-doc Maxime Geoffroy that aims to relate the content of pelagic trawls with acoustic measurements. The purpose of this is to monitor the seasonal position of the back-scatter layer in the water column and to document what it is composed of (mostly mesopelagic fish and krill as we’ve noted in our trawls). This project required us to perform MIK nets and pelagic trawls on the “Max transect” north of Svalbard. The sampling plan and transect position were changed slightly due to bad weather but we managed to get most of what we initially came here for, which was very satisfying. The trawls we conducted north of Svalbard contained very few polar cod but an impressive number of Sebastes sp. and Themisto libellula, a typically Arctic amphipod that polar cod feed on extensively.

Julia in the fish lab.

Throughout the cruise, we sampled opportunistically for a number of other projects, namely a project looking at capelin otoliths, another one looking at “anything that is rare and ugly – just like Carl”, we helped Erin with her attempt to gather ice associated amphipod north of Svalbard, and collected specimen for undergraduate courses back at UiT for Bodil and UNIS for Janne.

“Anything that is rare and ugly – just like Carl”
Atlantic cod found north of Svalbard. This kind of find is not uncommon now a day even though these species are typically boreal species. Their presence could be part of the reason why polar cod are absent in these areas.
Atlantic cod.

-Marine Cusa (Research Assistant, UiT)

What the fish crew was up to–post 1

January 9th 2017, Kongsfjorden, the hunt started once again. On a cruise like this one, most of us biologists are looking for specific critters. As it stands, it has almost become a tradition for the fish group to be on the lookout for polar cod. This endemic Arctic species is the most abundant cryopelagic fish at high latitudes and is believed to play an important role in the Arctic marine food web. In recent years, polar cod have not been doing so well on the west coast of Svalbard, and the increasingly warm Atlantic water seems to have displaced them for reasons that remain to be understood. This displacement might be explained by a change in prey or an increase in competition and predation due to the northward expansion of boreal fish, such as Atlantic cod. Because of this, and as I’ve mentioned it in the past, it has become increasingly difficult to find the little fellows on the west coast of Svalbard, and instead of a catch typically composed of Arctic species, ours are now most often composed of boreal species (whether it be fish or invertebrates). Because it lacks a sill, Kongsfjorden is particularly influenced by Atlantic advection and our trawls there testified this. They did contain some rare polar cod along with the more typically boreal Altantic cod, haddock, and capelin. Part of the goal of the polar cod project that is conducted by PhD student Morgan Bender is to document how these different water masses (Arctic versus Atlantic) affect polar cod reproduction and diet. To do so, we’ve been monitoring seasonally and annually their lengths, weight, body condition index, hepato- and gonado- somatic index, and their diet. To this, we’ve added in 2017 blood samples, histology measurements, and otoliths reading.

For this project, the ideal is to obtain polar cod of different size categories from Atlantic and Arctic fjords using both pelagic and demersal trawls. As previously mentioned however, finding polar cod in Atlantic fjords resembles a hide and seek hunt and can be quite frustrating. We did manage to find what we were looking for but we did not get a large sample size until we deployed the trawls in the north eastern part of Svalbard, in Rijpfjorden (nearly 600 specimen were caught in one trawl).

-Marine Cusa (Research Assistant, UiT)

The importance of polar cod in an Arctic food web. Diagram by Marine Cusa.

 

 

CTD’s and why we filter water

Throughout the cruise, we have cast a lot of CTD’s. CTD stands for conductivity (or salinity), temperature, and depth. In oceanography, a CTD is a regularly used instrument that is dropped vertically in the water column to measure water properties (the C, T, and D) at different depths. CTD’s are usually attached to large bottles that collect sea water at different depths. In the video below, the crew brings up the CTD rosette, and Martí and Peter begin filtering water.

Why do we need to know the properties of ocean water? To learn more about where certain animals live in the ocean, we use instruments like CTD’s to determine different water properties at various depths. We can then use this type of data and correlate it to the type of animlas or plants we find there, and further study how tiny marine critters can survive in different areas (or habitats) of the ocean.

Phytoplankton (tiny ocean plants) are essential for many marine animals. By filtering sea water, we can collect these small plants (as well as dead organic material) on filters with microscopic holes. Therefore, filtering water can give an indication of the amount of food available to small marine life (as Coralie mentioned in her post). Martí filters water for his project to learn more about the microbial food web during the polar night.

CTD data can also be used to compare water properties at similar locations through time. The water in western Svalbard is influenced by warmer and saltier water from the Atlantic Ocean moving its way northward into the Arctic Ocean. To determine if some of the fjords in western Svalbard will be ice-covered this year, researchers can investigate water temperatures using a CTD (see figure below). Some of the researchers on our cruise have summarized their findings on this University Centre in Svalbard (UNIS) page.

A temperature profile obtained from a CTD. Here you can see that surface water temperatures in 2016 were colder than in 2017 in Isfjord (IsK). What this indicates is that there is more Atlantic water inside Isfjord than last year, so the chances of an ice-covered Isfjord is unlikely this winter. Graphic credit: Ragnheid Skogseth/UNIS.
Coralie, Peter, and Martí around the CTD rosette.
Peter is boss when it comes to water filtration!

-Erin Kunisch (PhD candidate, UiT)

Pelagic trawling

We will also have more posts from the fish crew, but here are some photos of the fish crew and what kind of organisms they are finding up north.

-Erin Kunisch (PhD candidate, UiT)

The fish crew met onboard (before Ny Ålesund) to go through protocols.
One of the first pelagic hauls. Haddock, Sebastes (red fish), and Atlantic cod make up the larger fish you see here.
Marine showing Nestor, Paul, and Julia some of the noticeable differences between some of the fish in the trawl.
There are also a lot of tiny organisms caught in these trawls! These are Euphausiids (krill). They are small crustaceans that are important members of the Arctic food web, because they eat phytoplankton (very tiny ocean plants) and are eaten by bigger marine organisms like fish and whales.
Marine measuring and weighing the tiny organisms (a sample of the larger fish caught in the trawls are also measured and weighed).
Julia recording data.
Not the best place for this little fish to be!

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.