Sampling has begun!

This summer we participated on a research cruise to the Arctic Mid-Ocean Ridge (AMOR) with the KGJ Centre for Deep-Sea Research. This was the first cruise with dedicated sampling for the Vent & Seep Fauna project. Due to COVID restrictions, the cruise started a bit slow with a 10-day on-ship quarantine for all the participants. During this time the ship had to stay close to shore, but this allowed for some bonus-sampling for other projects in the beautiful Sognefjord.

Luckily no-one got sick during the quarantine, so after the 10 days we headed for the AMOR to sample some hydrothermal vents. We were only a very limited number of people on board this year, and the rest of the team tried to follow the dives from home with a live connection through Zoom. Even fieldwork has reached the digital age!

The main sampling-aims for our project this year was a comprehensive sampling of the Ægir’s Kilde vent field, and Mohns Treasure, an extinct vent field. At Ægir’s Kilde, there are multiple chimneys with white or shimmering, warm fluids streaming out. At the base of the chimneys there are amphipods and tiny snails, which are typically fund at hydrothermal vents on the AMOR. In addition we saw several fish relaxing near the vent. These fish belong to the eelpout-family, and are believed to feed on the vent-amphipods.

Fish relaxing near a hydrothermal vent chimney at Ægirs Kilde vent field

We also found some diffuse low-temperature venting with a bush of worms, possibly Sclerolinum contortum. We got some samples, and are looking forward to finding out what else might be hiding in this worm bush!

Diffuse venting and bush of worms at Ægirs Kilde vent field

The other target locality for the Vent & Seep Fauna project on this years cruise was Mohns Treasure. This is an extinct vent field, and one might wonder why we are interested in it? There are some records of species usually considered to be vent-specific that might still be found at extinct vent sites. It is possible that these sites might support some vent fauna, at least for some time after venting has ceased. So we wanted to get some samples to see if we find any overlap with our active vent sites. However, to our surprise, we found more than we hoped for! After flying around with the ROV for a while, mapping the area, we came across some diffuse venting. White bacterial mats were easy to spot, and when we zoomed in we could see amphipods and tiny snails that look suspiciously like the vent fauna we find at other sites on the AMOR. We got some samples, and morphological analyses and DNA-barcoding will tell us if they are indeed the same species.

Diffuse venting at Mohns Treasure with amphipods and gastropods

Despite the COVID-restrictions we were very happy with the outcome of this years cruise, and got a lot of good samples that will keep us busy!