Monthly Archives: November 2014

Pictures from the Faroes cruise

Faroes panorama AR

 

Now that we are back from a very successful cruise to the Faroes and Viking Bank, we can decorate the website with some of the many pictures that were taken on the cruise.  Shortly I will put up a page on the Pictures menu, but first, Alejandro’s Flickr page is worth a visit for some stunning seascapes (such as the moody panaorama of the Faroes above) and pictures of some of the wildlife which paid us a temporary visit before being returned to the deep …

Hermit Crab AR

The business end of a hermit crab Photo Alejandro Roman

 

 

A change in the weather and a change of scenery

Glycymeris PB

Glycymeris glycymeris from Faroes Bank. Picture: Paul Butler

Morning of 13th November:  Continuing our shells collection cruise, our next site, a little further south on the Faroes Bank, came up with another surprise: hundreds of live collected specimens of Glycymeris glycymeris.  We know this species (which can live up to 200 years) from St Kilda, the west coats of Scotland and points south, but we weren’t expecting to find it this far west in the north Atlantic and as far as I know it has not been found elsewhere in the Faroes.

Sea PB2

Heavy weather between the Faroes and Viking Bank. Picture: Paul Butler

Shortly afterwards, the weather began to turn, and in the light of predicted bad weather around the Faroes, we decided to head across to our other main area of interest, where we were planning to collect shells for Tamara.  This was Viking Bank in the northern North Sea/Norwegian Sea.  Tamara and Rob planned a full 80 potential stations in three separate areas.  Winds reached force 8 on the journey across to Viking Bank, and we were thankful for the relative stability of GO Sars.  At a session of presentations in the ship’s seminar room, we got a bit of detail about the very promising progress with the ARAMACC projects.

However, when we resumed dredging earlier this morning, the first tow on Viking Bank turned up nothing except a few chunks of mud.

Evening of 14th November:  We’ve worked on two main sites on Viking Bank with variable success.  Modern Arctica islandica here are small compared with specimens from earlier in the Holocene.  This may reflect sea level rise in the area: early Holocene specimens, living when large parts of the North Sea were still dry land, would have been living in coastal environments, with more nutrients, and were therefore able to grow faster than is possible nowadays.  These older shells have the kind of size and thickness that we see nowadays in Arctica from around the UK coast.

While some trawls turned up the older shells in large numbers, more recent specimens, and especially the live animals that Tamara was most interested in seemed to be more elusive.  A small adjustment to the connection between the winch and the dredge may have had the effect of allowing the dredge to dig deeper into the sediment, and the final trawl of the afternoon shift produced about 30 live clams.

 

 

 

 

Arctica gold in the Faroes

GO Sars PB2

GO Sars waits in Bergen before beginning the ARAMACC cruise to the Faroes. Picture: Paul Butler

We left Bergen at 17:00 Saturday 8th Nov, and took a 36 hour transit to first station (the seas reasonably calm considering the time of year), arriving at our first collection site off the SE of the Faroes at about 5am Monday 10th Nov.

10th November: With sauna, solarium and gym, GO Sars is a well equipped ship.  I’m not sure how much time we’ll have to use them though, since all the scientists will spend 12 hours of each day collecting and processing shells (and some are having to spend time in their rooms “acclimatizing” to life at sea).  For the past 24 hours we have been working off the SE side of the Faroes, at a grid of sites where Arctica has been collected before.  Here, we’ve collected a fair number of dead shells and a few live specimens, and also some shells from animals that died more recently (articulated shells* – these are cases where the two valves are still attached even though there is no animal inside them).  Most of the dead shells are of uncertain date; experience of other sites suggests that they could have lived anything from a few hundred to a few thousand years ago.  They are generally in good condition, however, and may easily contribute to a long chronology.

Shovelling Arctica NW2

Rob Witbaard (left) and Juan Estrella shovel a pile of shells – mostly dead Arctica valves – that have just been dredged from a site off the SW Faroes. Picture: Nina Whitney

Morning of 11th November: Switching the following night to a site off the SW of the islands, we struck dead Arctica gold.  The four dredges we hauled (for six minutes each) were brimful with shell material, nearly all of it single Arctica valves.  All told we may have collected 5,000 shells in these four dredges, suggesting that the sea floor in this area is covered in these shells.  Live material was less abundant (there may be a number of reasons for our not collecting live animals as efficiently as we might have, including the effectiveness of the dredge, or the possibility that at this time of the year many animals may burrow further into the sediment), but we did retrieve thirty or so live animals, and also a large number of articulated pairs, which can generally be assumed to be very recently dead*.

 

 

 

 

*This is important for chronology construction.  Shells from live collected animals with a known date of death can be used to anchor the chronology, while the articulated shells can be assumed from their condition to have died very   recently and should easily crossmatch with the live specimens.