Cruise 2008: Guaymas Basin and East Pacific Rise Cruise

FWF research project No. P20190-B17


Quantitative Meiobenthos Collections

10/13/2008 - 11/05/2008

Chief scientist: Stefan Sievert (Woods Hole Oceanographic Institution, USA)

Austrian participants:

Laura-Amelie Riavitz

Research Vessel Atlantis

Deep Submergence Vehicle Alvin

We were invited to continue our meiofauna research at deep-sea hydrothermal vents at the East Pacific Rise 9°N. We would like to thank S. Sievert for his support.

General information about Alvin and Atlantis and all cruises are provided on the WHOI website.

Guaymas Basin

At Guaymas we were able to collect sediment cores. The sediment samples were covered with sulphide-oxidizing bacteria which form distinctive white mats. With these samples we want to characterize the vertical distribution of meiofauna occurring in this region.

Collections of the sediment cores

East Pacific Rise

We study the succession of vent meiofauna after an eruption has wiped out almost all animals in 2006 (see cruise reports from Ladder 1, 2, 3)

During this cruise I collected bare basalt. This samples will provide important information on how widely distributed vent meiofauna is and what communities are found within the AST (axial summit trough), an almost neglected habitat.

The basalt pieces were grabbed with the hydraulic arm of Alvin at least 10 m away from hydrothermal vent flux where no fauna was visible. Basalt pieces were put into bioboxes on the basket of Alvin and were transported to the surface. On the ship, I sorted the fauna and fixed the animals in formaldehyde or ethanol for later analyses in Austria.

The hydraulic arm of Alvin collecting bare basalt


                        Alvin back from its dive with the samples                        Antje and Laura extracting and fixing the animals from the basalt

CTD casts

Other scientists on board made CTD casts to take water samples from different depths and locations. During the cruise I helped them with this work and learned how to do CTD casts. CTD casts were conducted in the evening, as during Alvin dives no other devices were allowed in the water. Water samples were used to observe microorganism from the different depths.

Emelia and Laura at work

A special visit from the NBC

During our stay at Guayamas the RV Atlantis was used as a special location for the NBC “Today Show”. The famous television news journalist Ann Curry accompanied WHOI Senior Scientist Jeff Seewald and pilot Bruce Strickrott on an Alvin dive to the Hydrothermal Vents at Guayams Basin. While on the ship, the NBC crew filmed scientists working in the labs and interviewed among others chief scientist Stefan Sievert. The dive was conducted and recorded for a special segment focused on “the ends of the Earth”.

Ann Curry and Jeff Seewald being interviewed after their amazing dive