East Pacfic Rise: LADDER 1

funded by Austrian Science Foundation grant P16774-B03

Projects:

Kitchen sponges - new device for quantitative meiofauna collections

The new vent site 2 in 1

TASCs - the more the better

Its fun to dive

10/24/2006 - 11/18/2006

Chief scientist: Andreas Thurnherr (Lamont-Doherty Earth Observatory, USA)

Austrian participants:

Monika Bright, Sabine Gollner, Sigrid Katz, Bettina Pflugfelder, Andreas Laschober (journalist)

Research Vessel Atlantis

Deep Submerged Vehicle Alvin

For the first time in Austrian history, we were able to receive fundings for two Alvin dives to study the meiobenthic communities at the East Pacific Rise. In addition, Lauren Mullineaux, James Ledwell, and Andreas Thurnherr were very generous in sharing their dives so that we could collect a lot of samples and carry out many deployments and recoveries of our collection devices. We would like to thank them for their support.

More informations about Alvin and Atlantis and all cruises are provided on the WHOI website.

Kitchen sponges - new device for quantitative meiofauna collections

After a volcanic eruption in this region earlier 2006, we initiated a project to investigate the succession of meiofauna. The objective of this study is to characterize the succession in meiobenthic chemosynthetic communities and to discover the dispersal mechanims of meiofauna at vents. For this we used standard plastic kitchen sponges, known to be colonized by meiofauna.

                 

                                                 Sponges + TASCs                                                                            sponges underwater

Diving along the axial summit collapse through in this region, we found several old vents sites with extant communities, such as the pompej worm Alvinella. Other sites still extisted, but vent flow ceased and the fauna, although still in place was either dead or dying such as mussels, tubeworms, or pompej worms. We found also that some of the old sites as well as newly discovered sites were colonized with the small tubeworm Tevnia.

                  

                                           Alvinella aggregation                                                                           dead tubes and shells

           

                                                    Tevnia community                                                                   bare basalt community

In order to find out whether or not vent meiobenthos disperses through the water column, we deployed the kitchen sponges also on a set of moorings at different locations and altitude.

               

The new vent site 2 in 1

We discovered at new site at the northern edge of our study site, 9.8553555 longitude, 104.2934786 latitude, in 2508 meters death on the top. Called 2 in 1, it consists of two areas, one with patches of white bacterial mats, the other one on the eastern wall of the steep, narrow axial summit collapse through with lots of diffuse flow and Tevnia. Due to the narrow axial summit collapse through, this site is not accessible for Alvin.

2 in 1

TASCs - the more the better

We have been using TASCs (tubeworm artificial settlement cubes) for collecting tiny tubeworm babies for several years now. Because our last deployments from December 2004, shortly before the eruption in spring 2006 were covered under lava, we deployed a new set of TASCs, this time in Tevnia aggregations.

TACSs in Tevnia clump

It's fun to dive

Sigrid Katz and Bettina Pflugfelder were able to dive for the first time with Alvin. For Sabine Gollner it was the second dive and Monika Bright had her 10th and 11th dive with Alvin.

                

                                        Sabine, Mike and Bruce                                                                             Bettina and Pat

             

                                                            Sigrid                                                                                      Monika and Gavin