Van Mooy KN207-01

Ship

Cruise Party

Departure: Apr 21, 2012

Arrival: May 4, 2012

Operations Area

Science Objectives

Intact polar diacyglycerols (IP-DAGs) are the fatty-acid bearing lipid molecules that compose bacterial and eukaryotic cell membranes.  As such, they are one of the most abundant classes of lipid molecules in plankton, and play a major role in the marine carbon cycle.  However, until very recently, the molecular diversity of IP-DAGs was poorly understood; the structural identity and characteristics of IP-DAGs were inferred almost exclusively from their constituent fatty acids.  Led by advances in high performance liquid chromatography/mass spectrometry (HPLC/MS) methods, we have established that the IP-DAGs in the upper ocean are dominated by sulfolipids and betaine lipids.  These non-phosphorus containing IP-DAGs were largely unknown to chemical oceanography.  In contrast, phospholipids, which have been the focus of considerable research, compose a disproportionally small fraction of total IP-DAGs.  Over the last three years we have made some progress in understanding the planktonic origins of non-phosphorus IP-DAGs and have identified the possibility that sulfolipids and betaine lipids are substituted for phospholipids by phytoplankton when dissolved phosphate becomes scarce.  But we still lack even a cursory understanding of biochemical functions and geochemical fates of non-phosphorus IP-DAGs.  Given that these molecules are among the most abundant lipid molecules on the planet, this represents a profound and unexpected gap in our understanding the marine carbon and phosphorus cycles.  In this proposal we outline a research plan to begin to rectify this situation.  Specifically, we will ask:

•  How do non-phosphorus lipids contribute to variations in the C:N:P of particulate organic matter in the Sargasso Sea?

•  What are the relative degradation rates of phospholipids and non-phosphorus lipids in surface waters?

•  Which groups of microbes utilize the carbon and phosphorus from different IP-DAGs?

 • What are the relative contributions of different IP-DAGs to particulate organic matter export to the deep-sea?

Science Activities

Additional Info

Stations:

Supporting documentation:

Shipboard Equipment

Shipboard Communication

CTD/Water Sampling

Critical CTD Sensors

Hydrographic Analysis Equipment

MET Sensors

Sample Storage

Navigation

Navigation

Winches

Wire use and application

Standard Oceanographic Cables

Portable Vans

Specialized Deck Equipment

Over the Side Equipment

Special Requirements

Additional Cruise Items/Activities

Hazardous Material

Radioactive Material

Additional Information

Checklist

BERMUDA:

Office: (508)-289-3811
Mobile: (617)-999-4163
Email: csmith@whoi.edu

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