Deployment: OC454-02

This cruise aboard Oceanus from Piraievs, Greece did field work in the Mediterranean Sea for the NSF OCE funded project: "Pickled Protists or Community Uniquely Adapted to Hypersalinity?".

The cruise dates are from the Final UNOLS schedule (ID #10808 Version #7 Date: 1/5/2010) and agree with the cruise dates specified in the UNOLS Post-Cruise Assessment Report filed by the Chief Scientist.  The cruise dates, 7-25 - 8-05-2009, from the R2R cruise catalog include the previous transit cruise during which no sampling was done for this project.

The original science objectives included collection of water column and sediment samples at 3 different hypersaline anoxic basins, L'Atalante, Discovery, and Urania. The plan was to collect Niskin samples and SID samples (a WHOI sampler that carries out in situ fixation) from above the halocline, within the halocline, and within the brine of each basin (3 depths, two types of samples per depth, Niskin and SID). Researchers also planned to collect multicores from the bottom sediments where the halocline impinged on the seafloor, a reference sample from above the halocline, and a sample within the brine (3 depths along a transect through the halocline) from two of the basins.

Science activities conducted during the cruise included sampling in two of the three basins, Discovery and Urania Basin:

(1) 11 CTD casts to various depths as needed to support sampling objectives as determined by the depth of the halocline

(2) Water samples were collected from Niskin bottle from 3 designated depths from two basins

(3) SID samples were collected from Discovery Basin, but the SID  malfunctioned due to extreme depth before a complete sampling program could be completed in Urania Basin

(4) Partially successful deployments of the multicorer at Discovery Basin yielded some multicores from within the brine and above
the halocline, but attempts to collect a halocline sample were unsuccessful.  A brine sediment sample was successfully collected at Urania Basin, but repeated attempts to collect multicores failed.

Multicore sampling was negatively affected by several factors: the tubes failed to close properly, the multicorer didn't fire properly, and researchers had difficulty locating the halocline since neither the multicorer nor the CTD instrument package had a functioning camera system.

Although the original cruise plan included sample collection in a third basin (L'Atalante Basin), only two basins were occupied.  The cruise plan was adjusted when equipment malfunctions negatively impacted the success of the coring work.  The decision was made that co-PI Bernhard should collect some sediment cores from the second basin, Urania Basin, on the last day of the cruise instead of conducting the water column sampling in the third basin.

More information is included in the 4 August 2010 Cruise report prepared by K. Kormas, M. Pachiadaki and P. Sigala (cruise report PDF file).

Funded by: NSF OCE-0849578 (see abstract from NSF site)

Cruise information and original data are available from the NSF R2R data catalog