A long night of science

We arrived at station HG-I, in the eastern Fram Strait, at 9 pm. Our icy surroundings had been replaced by open water as we steamed eastward, and the air was a balmy 5 C. I barely needed my second jacket to step outside. 

A sample at 9 pm isn't too bad. Research operations on Polarstern take place 24 hours a day, so sometimes the schedule has me sampling in the middle of the night. Everybody takes their turn at the night shift - that's just how it is. We'll sort this sample, I thought, then get some sleep and rise for our next sample in the morning. 

Yeah, not so much. 

The HG-I sample was our most diverse one yet. There were so many larvae in our net - and not all the same species. We had three different brittle stars, two different worms, three types of snails, a barnacle, a little trochophore, and I don't even know how many clams. Insanity!

A map showing the two main currents in the Fram
Strait and the location of HG-I (yellow star).

Plus, the ship was running ahead of schedule. I don't know how or why, but this expedition, everything is going so smoothly that we're almost always right on time or a little ahead of schedule. We were still sorting our first net tow from HG-I when it was time for our next sample! We ended up getting backed up 3 samples deep, sleeping only 3 hours, and splitting some samples in half just to keep up. 

Ladies and gentlemen, this is why we work in the Fram Strait. This deep, narrow passage of water between Greenland and Svalbard is a microcosm of environmental conditions. In the space of just about 100 nautical miles, we went from heavy ice cover and clear water in the East Greenland Current to open water, warmer temperatures, and high biodiversity in the West Spitsbergen Current. Every time I'm up here, I am reminded of the stark contrast between these two currents and the far-reaching implications for biodiversity in the Arctic. 

The West Spitsbergen Current brings warm, high-nutrient water from the north Atlantic, through the Fram Strait, and into the central Arctic. The current carries with it all sorts of zooplankton, including larvae. Species from the coast of Svalbard get entrained in the West Spitsbergen Current and carried to new fjords. Some larvae from the North Atlantic can get caught in it, too, and disperse into the Arctic Ocean. One of my team's goals is actually to figure out whether the West Spitsbergen Current is bringing new species into the Arctic basin from lower latitudes. 

The East Greenland Current, on the other side of the Fram Strait, is a whole different world. Cold, clear water from the central Arctic flows southward through the East Greenland Current. Larvae can get entrained in both currents, but because there are fewer species living and reproducing in the central Arctic, we generally find less stuff in East Greenland. Mostly, the East Greenland Current carries ice floes southward, where they melt and deposit the stones they're carrying on the seafloor.

It was a long, sleepless night of larval sorting, but our data look amazing. I am very pleased.