Field work in Billefjorden 2: Glacial impact on fjord ecosystems

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Last week SIZE PhD Candidates Ulrike Dietrich, Christine Dybwad and Tobias Vonnahme went for their second part of the field campaign in Billefjorden on Svalbard. Together with Josef Elster from the Centre of Polar Ecology in the Czech Republic, they studied the impacts of different glacier types on the ecosystems in the fjord.

The Czech research vessel Clione, a 15m sailing boat, brought us to Billefjorden and all our sampling sites. Thanks, to the great 1st mate Jirka and the skipper Honza, we were able to repeat all sampling from our first winter campaign in winter plus a few additional stations and sampling for colleagues at UNIS, Akvaplan, SLU, and NTNU. An anchor winch turned out to be very helpful for lifting heavy gear up from the deep.

Our first main station was right front of the tidewater outlet glacier NordenskiĆøldbreen. The area was full of birds, seals, and a large group of belugas indicating high amount of food available. The water was milky and partly covered with ice blocks from the glacier. A few minutes after we deployed the first sediment trap, the glacier started rumbling and a wall of ice fell into the sea, which is known as calving. Soon afterwards, the area around the sediment trap was covered in ice. We hope to follow the inputs of freshwater from the glacier after analysing a long term CTD measurement attached to the sediment trap. A first look into the sediment trap showed quite some inorganic material including dropstones from the glacial ice blocks.

The second main station was further out at a site where we sampled the ice edge in April. The water was much clearer and the particles in the water appeared to be mainly zooplankton feces.

Zooplankton sampling with a WP2 net
Recovering a sediment trap, thanks to a creative skipper and an anchor winch

The zooplankton community in both stations was dominated by copepods with quite a few additional arctic species, fish larvae and jellyfish and ctenophores. A first look at the algae communities showed no diatoms, except one freshwater species near the glacier front, but a few autotrophic nanoflagellates, such as dinoflagellates and haptophytes. Further analyses of our DNA and RNA samples and a detailed investigation of our algae and zooplankton samples will complete the picture.

Ulrike, doing DNA and RNA filtrations on board, right after getting the water
Christine, fixing zooplankton samples on board

The glacier was free of snow and cryoconites (sediment filled holes in the glacier) were abundant. We sampled cryoconites in areas sampled since 2014, which are usually dominated by green algae, Zygnemales and Cyanobacteria and tardigrades, rotifers and ciliates as the only grazers.

Water sampling on the glacier
cryoconite sampling

Unfortunately, we had to leave the fjord 2 days earlier than planned due to a storm coming up. Our last sampling site for UNIS ended up at rough sea in the middle of Isfjorden in the early morning after a night of steaming back interrupted by last minute CTD casts and glacier sampling, making the field campaign a full success.