The small creatures
We are not alone out here. Besides the sporadic visits of the majestic king of the arctic, the polar bear, and the vigilant flight of different types of Arctic birds, we don’t see many living creatures up here in the high north. But we, the biology team onboard Lance, know that there are tiny animals and plants out there thriving in the most unimaginable habitats.
We know that there are single celled algae living in the water and in the ice (they are called phytoplankton and sea ice algae). And we also know that there are small shrimp-like animals (zooplankton) that like to feed on those algae.
Since phytoplankton and sea ice algae are tiny and can’t be spotted by eye, in order to find them, we have to ask ourselves: “If I was an Arctic algae, where would I like to live? I like sunlight and nutrients (my food), and my enemies are zooplankton grazers and strong currents.”
Thick ice and snow prevent sunlight from reaching the sea water, which is where the nutrients and the grazers are. Therefore, sea ice algae are usually found in higher concentrations at the bottom of the sea ice. However, during our observations on our home floes, during Leg 5 and 6, we have discovered greenish, brownish layers of algae thriving in a wide variety of environments. We found them for example in ridges and below the snow in flooded areas.
Besides sampling and measuring lots of biological parameters on these communities (how much carbon they fix, what kind of pigments they have, how much sunlight they absorb, etc.), we also interviewed them and asked them why they like to live in those peculiar environments. Here you have their answers:
Phaeocystis from the Water Column Kingdom
I am the king of the Water Column. I can grow fast even at low light conditions and I use up the abundant nutrients available. Currents move me around and sometimes I am lucky and get some extra light, if they take me to open waters, or below an open lead in the pack ice.
To protect myself from grazers I form big round mucous colonies, which clog the researcher’s nets and filters.
Nitzschia from the South Ledge Kingdom
I’m used to life in the sea ice. My long and thin shape makes me perfect for the brine channels in the sea ice. I like to grow attached to surfaces so that I can slide on them and move searching for light and nutrients.
Living at the bottom of the sea ice can be risky since strong warm water currents can erode the bottom of the ice quickly and wash me away. That’s why I decided to set up my new home in the sea ice ledges that form ridges. If I choose the right side, I’m much more protected from the currents.
Thalassiosira from the Snow Slush Kingdom
I usually live in the water column together with my colleague Phaeocystis. However, he’s much more efficient in taking up the nutrients and is better protected against grazers. That’s why, this year when I suddenly got infiltrated through cracks from the water column into the upper layers of the ice just below the thick snow, I found my perfect new home and I started building long chains.
The snow protects me from getting sunburnt, but I get more light than below the ice. Also, the ice gives me a good substrate to grow forming chains happily and I get nutrients from the sea water that comes up through the cracks. In addition, I’m fairly well protected against under ice grazers. What else could I ask for?
Calanus glacialis from the Under Ice Kingdom
I love eating sea ice algae, they give me the energy to reproduce, but sometimes they are hard to find since they hide in ridges or simply in the ice. The best time for me is when they fall from the ice – it’s like a rain of food. And you’re telling me there’s more of this tasty algae growing between the snow and the ice? I have to figure out how to get there…